k^cwae® raovd[r?§ow_ LIBRARY OF THE MASS. MED. COLLEGE. Rules and Regulations. 1. Students attending any of the Lectures in the Massachusetts Medical College may take books from the Library during the course, by depositing Five Dollars with the Dean ; and the students of any of the Medical Professors may have the same privilege on the same terms throughout the year. 2. The Library shall be open on the afternoon of every Saturday, from 3 to 5 o'clock, for the de- livp.rv ___v_L_i_ai_irrx .__f l.<-/-lr_.______________■______________ -^ ■S and Surgeon General's Office ZD m !___»_*' Z/ec&on, the sum deposited; otherwise the whole amount will be returned to the depositor, when he ceases to use the Library. '^rNj \ . - ^■^xP^x •%, THE PRINCIPLES AND PRACTICE OPHTHALMIC MEDICINE AND/SURGEM T. WHARTON JONES, F.R.S., LECTURER ON ANATOMY, PHYSIOLOGY AND PATHOLOGY AT THE CHARING CROSS HOSPITAL; FOREIGN MEMBER OF THE ROYAL MEDICAL SOCIETY OF COPENHAGEN; CORRESPONDING MEMBER OF THE IMPERIAL ROYAL MEDICAL SOCIETY OF VIENNA, ETC. ETC. ONE HUNDRED AND TWO ILLUSTRATIONS. EBITED BY ISAAC HAYS, M. D., SURGEON TO WILLS HOSPITAL, ETC. yfcONGF-' \ PHILADELPHIA: LEA AND BLANCHARD 1847. / 1/V tf Entered according to Act of Congress, in the year 1847, by LEA AND BLANCHARD, in the Clerk's Office of the District Court for the Eastern District of Pennsylvania. PHILADELPHIA: t. K. AND P. G. COLLINS, PRINTERS. "VUii _\ Enlargement and induration of the Meibomian glands - - 413 Vesicles or phlyctenule on the cutaneous surface of the eyelid near its margin - - - " - - 415 Warts on the eyelids - - - " ' ' .1(- Horny-like excrescences connected with the skin of the eyelids - - *xo Encysted steatomatous tumour of the eyelids ' 41Q Grando and chalazion - - - " -418 Encysted tumour of the eyelids -"'.,' ' A18 Hydatids in the cellular substance of the eyelids - - ' ' *l° Nevus maternus and aneurism by anastomosis of the region of fa ^ Scirrhoid callosity of the eyelids - ] 41_ Cancer of fa eyelids "","." ' 420 Phtheiriasis of the eyebrows and eyelashes • XVI CONTENTS. CHAPTER VIII. Section I.—DISEASES OF THE CONJUNCTIVA - - - 421 Pterygium........-- 421 Pinguecula.......... 423 Trichosis bulbi - -.......423 Abnormal development, or hypertrophy of the conjunctiva cornee - 424 Fungous excrescence of the conjunctiva cor nee - 424 Various kinds of tumours of the conjunctiva - 425 Entozoa in the cellular tissue under the sclerotic conjunctiva - - 426 Section II.—DISEASES OF THE SEMILUNAR FOLD AND LACHRYMAL CARUNCLE.......426 Inflammation of the semilunar fold and lachrymal caruncle - -427 Catarrhal inflammation of the semilunar fold and lachrymal caruncle 427 Inflammation and abscess of the lachrymal caruncle - - - 428 Chronic enlargement of the lachrymal caruncle and semilunar fold 428 Polypous and fungous excrescences of the lachrymal caruncle and semilunar fold.........429 Cancer of the lachrymal caruncle - - - - . -429 CHAPTER IX. DISEASES OF THE LACHRYMAL ORGANS. Section I.—DISEASES OF THE SECRETING LACHRYMAL ORGANS...........430 Disordered states of the lachrymal secretion - 430 Suppression of the lachrymal secretion.....439 Epiphora or watery eye - - - - - - . -431 Inflammation of the lachrymal gland.....43 \ Fistula of the lachrymal gland, or true lachrymal fistula - - 432 Extirpation of tumours in the neighbourhood of the lachrymal gland or of the diseased gland itself -----. 432 Section II—DISEASES OF THE DERIVATIVE LACHRYMAL PASSAGES.........- 434 Inflammatory swelling, abscess, or sinuous ulcer in the region over the lachrymal sac.........405 Catarrhal inflammation of the derivative lachrymal passages - 435 Acute inflammation of the derivative lachrymal passages - . 436 Chronic inflammation of the derivative lachrymal passages - -438 Atony or relaxation of the lachrymal sac.....44O Mucocele.......1_ .. . Fistula of the lachrymal sac....... 442 Atony or relaxation of the papille, with a dilated state of the pumcta 442 Shrunk papilla and contracted state of the puncta - - .442 Obliteration or obstruction of fa lachrymal points and canalicules 443 CONTENTS. Xvii Exploration of the nasal duct, to determine whether it is obstructed or obliterated.........445 Obstruction of fa nasal duct, and fa different operative methods adopted with a view to remove it and to restore a passage to the tears ----------- 450 Obliteration of fa nasal duct ------- 456 Lachrymal, calculi --------- 457 CHAPTER X. DISEASES OF THE ORBIT. Section I—INFLAMMATIONS, &c, OF THE ORBIT - - 457 Inflammation of the orbital cellular tissue.....457 Inflammation of the periorbita and bones of the orbit - - - 459 Section II.—ORBITAL GROWTHS AND TUMOURS - - - 460 Sarcomatous tumours in the orbit - - - - - -461 Encysted tumours in the orbit - - - - - - -461 Operation of extirpating sarcomatous and encysted orbital tumours 461 Hydatidgenous cysts in the orbit ------ 462 Medullary tumour in the orbit ------- 462 Melanotic tumour in fa orbit.......463 Aneurism by anastomosis in the orbit ------ 463 True aneurism in the orbit ----- - 463 CHAPTER XI. INJURIES OF THE EYE. Section I.—INJURIES OF THE CONJUNCTIVA AND EYE- BALL ...........463 INJURIES OF THE CONJUNCTIVA FROM INTRUSION OF FOREIGN BO- DIES INTO THE OCULO-PALPEBRAL SPACE .... 463 Mechanical injuries....... " 464 Chemical injuries......" " 4"4 INJURIES OF THE EYEBALL AND ITS PROPER TUNICS - - - 466 Concussion of the eyeball........466 Contused wounds of the eyeball.......467 Dislocation of the eyeball Evulsion of fa eyeball B xviii CONTENTS. Section II.—INJURIES OF THE EYEBROW AND EYELIDS - 475 Contusion with ecchymosis ....... 475 Incised, lacerated, and contused wounds of the eyebrows and eyelids 476 Poisoned wounds - - - - - - - - -477 Burns and scalds --------- 477 Section III.—INJURIES OF THE LACHRYMAL ORGANS - 47S Injuries of the lachrymal gland and ducts - - - - - 478 Injuries of the derivative lachrymal organs.....478 Section IV.—INJURIES OF THE ORBIT.....480 Blows, fyt., on fa edge of the orbit......480 Penetrating wounds of fa orbit ...... 480 GLOSSARY.......... 4gl INDEX...........487 LIST OF WOOD ENGRAVINGS. 186 187 194 199 205 Figure 1. Duets of the lachrymal gland . . . Page 25 -------2. Characters of conjunctival and sclerotic vascularity . 30 -------3. Natural appearance of the iris and pupil in profile . 36 -------4. Abnormal do. do. do. . . 36 ■ 5. Forceps for plucking out eyelashes . . .53 -------6. Central opacity of the cornea concealing the pupil . 184 -------7. The same eye with the pupil dilated by belladonna . 184 -------8. Partial staphyloma -------9. Total spherical staphyloma -----10. Staphyloma knife . -----11. Iridauxesis (from Klemmer) -----12. Conical cornea -----13. Anterior radiated fissures of the lens . . . 224 -----14. The stellate appearance in cataract . . . 224 .-----15. The shadow thrown by the pupillary margin of the iris on the surface of a cataract . . . .225 -----16. Mode of securing the eyelids for operations for cataract and other operations on the eyeball . . • 242 ----- 17, 18, 19. The different sections of the cornea in the opera- tion of extraction of the cataract . . • 245 ------20. A cataract knife ...... 246 -----21. The act of making the lower section of the cornea . 247 ------22. Mode of holding the cataract knife . . . 247 . 23, 24. Faulty sections of the cornea . . . . . 252 -----25. Knife for enlarging the corneal section . . . 252 ------26,27. Daviel's scissors . . • • 253 ------28. Instrument for opening the cap^ile of the lens in extraction 255 ------29. Daviel's curette or spoon ..... 255 ------30. Maunoir's scissors . . . • • .258 ----- 31. Small hook . . . . • .258 ------32. Covering for the eye after operation . . • 260 -----33. Fine hooked forceps ..... 264 _____34. Diagram illustrating couching of the cataract . . 266 -----35. Diagram illustrating reclination .... 266 -----36, 37. Cataract needles, straight and curved . . . 267 _____38. Diagram illustrating sclerotic puncturation with a curved needle . . • • • ... 269 _____39. Diagram illustrating reclination through the cornea . 272 _____ 40. Diagram illustrating division through the cornea . . 277 ______41. Diagram illustrating artificial pupil by incision through the sclerotica ...... 284 .-----42. Adams' iris knife ...... 284 XX LIST OF WOOD ENGRAVINGS. Figure 43. Diagram illustrating the operation by incision through the sclerotica ...... 285 ■-----44, 45, 46, 47. Diagrams illustrating artificial pupil by incision through the cornea . . . . .286 •-----48. Maunoir's scissors ...... 287 ■-----49. Hooked forceps ...... 289 -----50. Tyrrell's hook . . . . . .289 1-----51. Mode of holding the curved scissors . . . 290 ■-----52. Diagram illustrating artificial pupil by central excision . 291 1-----53. Diagram illustrating artificial pupil by separation . . 292 -----54. Jaeger's keratome ...... 293 1-----55. Simple hook ...... 293 -----56,57,58,59,60. Diagrams illustrating artificial pupil by sepa- ration \ . . . . . 294, 295 -----61. Do. do. do. . . . . . . 296 -----62. Diagram illustrating artificial pupil by a combination of incision and excision . . . . .301 -----63. Coloboma iridis . . . . . . 303 -----64. Common muscae volitantes .... 323 -----65. Diagram illustrating complementary colours . . 331 1 66. Diagrams for stereoscopic experiment . . . 355 -----67. Diagram, from Ruete, illustrating the axes of revolution on which the eyeball is moved by its different muscles 360 -----68, 69. Illustrations of Adams' operation for ectropium . 386 -----70. Illustration of the operation for ectropium by transplanta- tion of skin . . . . . . 390 -----71, 72. Illustrations of the Author's operation for ectropium . 392 -----73. Illustration of Dieffenbach's operation for ectropium . 396 -----74, 75. Illustrations of eversion at the outer angle, and Wal- ther's operation of tarsoraphia .... 397 ■-----76, 77. Ectropium from caries of the orbit, and Ammon's ope- ration • • • • . . 398 - 78. Graefe's entropium forceps - 79. Trichiasis ...... - 80. Horn spatula for introducing behind the eyelids in operating on them .... • 81. Pterygium ..... ■ 82. Trichosis bulbi . • ■ 83. Knife for incision of the lachrymal sac • 84. Operation of incision of the lachrymal sac ■ 85. Catgut style for dilating the nasal duct ■ 86, 87. Metallic styles .... 88, 89. Gold tubes for insertion into the nasal duct 90. Conductor or handle for inserting the tube 401 404 406 421 423 447 448 452 453 454 455 EXPLANATION OF THE PLATES. PLATE I. Figure 1.—This represents catarrhal inflammation of the conjunctiva, as described in ss. 301-309 and 454-459; and also the mode of examining the conjunctival surface of the lower eyelid, as described in s. 34. Figure 2.—A well-developed granular state of the conjunctiva of the upper eyelid in Egyptian ophthalmia, as described in ss. 495 and 983. The enlarged papillae are separated into groups by furrows or fissures. The figure also illustrates the mode of examining the conjunctival surface of the upper eyelid, as described in s. 36. Figure 3.—A case of phlyctenular, or scrofulous ophthalmia, in which there is a burst phlyctenula on the cornea, with a fasciculus of vessels run- ning from the conjunctiva into it, as described at s. 625. This figure also illustrates the mode of examining the eye in such cases, which occur in children, and in which there is great intolerance of light, as described in ss. 54, 56. Fig. 1. PLATE I. Fig. 2. Fig. 3. PLATE IL Figure 1.—This figure represents a case of iritis, as above described in s. 364 et seq.; and also illustrates the mode of depressing the lower eyelid for examination of the front of the eyeball. See ss. 50-56. Figure 2.—Arthritic iritis, as described in ss. 830-835. Figure 3.—Arthritic posterior internal ophthalmia, as described in ss. 894 -904. The figure also illustrates the mode of raising the upper eyelid for examination of the front of the eyeball. See ss. 50-56. m PLATE II. Fig. 3. PLATE HI. Figure 1.—This represents a case of medullary fungus of the eyeball in its second stage, as described in s. 1167 et seq. Figure 2.—A case of sclerotic staphyloma from traumatic inflammation of the eye. In this figure there is a good representation of varicose vessels. See ss. 875, 1075, &c. Figure 3.—A case of melanosis of the eyeball, in which the iris has been detached at one part of its Circumference, and the black mass is making its appearance from behind, as also through the sclerotica near the cornea. See s. 1193 et seq. PLATE III. Fig. 2. Fig. 3. PLATE IV. Figure 1.—The third case of hydatid in the anterior chamber, referred to in ss. 1150,1151. The body and head of the animal are protruded from the tail vesicle. Figure 2—Represents a case of dislocation of the lens into the anterior chamber; the lens being still clear, see s. 2641 et seq. This figure also illustrates the mode of fully exposing the front of the eyeball for examina- tion, as above described in s. 50. Figure 3—Represents the third case of cyst, in connection with the iris, above described in s. 1164. ' Fig. 1. PLATE IV. Fig. -. INTRODUCTION. PECULIARITIES OF OPHTHALMIC MEDICINE AND SURGERY. As there enter into the composition of the eye all the various tissues of the body, to say nothing of tissues pecu- liar to itself, so the same elementary forms of disease present themselves in it as in other parts; and so far the pathology and therapeutics of the organ of vision admit of being illustrated by, and are capable of illustrating, general pathology and therapeutics; the latter the more especially, as from the external situation of the eye, and the transpa- rency of its front, the progress of disease and the effects of remedies may be observed, which in other parts of the body can only be guessed at. But as all organs differ from each other in respect to structure as organs, and in respect to function, so also do they differ in respect to special pathology and therapeutics. In the case of the eye, these points of difference are per- haps more numerous and decided than in any other organ. From this it is evident, that, although diseases of the eye must be treated on the same general principles as the dis- eases of any other part of the body, yet in consequence of the great peculiarity of its structure and functions, it is unsafe in practice to trust to these general principles only; for much depends on the observance of numerous minute details. Such being the case, and considering the importance of the organ of vision, a course of medical education cannot be considered complete unless ophthalmic medicine and surgery have for some time specially engaged the student's attention. XXX INTRODUCTION. HISTORY OF OPHTHALMIC MEDICINE AND SURGERY. The oculists of Egypt,—a country where diseases of the eye are endemic,—were in early times in request among the other nations of the East, as appears from the story in Herodotus, of Cyrus, King of Persia, sending to Amasis, King of Egypt, for the most expert oculist of his dominions. From Egypt the art of treating diseases of the eye was introduced into Greece. The'Greeks being good observers, we find that, notwithstanding the want of accurate ana- tomical knowledge, which materially obstructed their study of the diseases of other organs, they were enabled, on account of the exposed situation of the eye and its trans- parency, to become great proficients in ophthalmic medi- cine and surgery. Some idea of the extent of the know- ledge of the diseases of the eye possessed by the Greeks may be had, by considering that many of the names now in use have actually descended from them, and by casting a glance at the summary given by Celsus; for though Celsus wrote at Rome, it is to be remembered that his sur- gery was entirely that of the Greeks. As the Greeks received from the Egyptians their first instructions in the art of healing, so the Romans were debtors to the Greeks. In fact, the medical practitioners of ancient Rome were either Greeks or persons who had been educated in the schools of Greece. That medici ocu- larii were not wanting among the Romans, we have suffi- cient evidence in the inscriptions on seals, &c, which are ,to be met with in collections of antiques. Ophthalmic medicine and surgery continued to be suc- cessfully cultivated and practised by the later Greeks, and much on the diseases of the eye is contained in the works of the Arabian writers, derived, no doubt, from the Greek manuscripts which fell into their hands. Until the commencement of the last century, little more was known of the diseases of the eye than what is found in the Greek and Arabian writers. But as the anatomy and physiology of the eye began to be more carefully studied, so its diseases became better understood. The INTRODUCTION. XXXI true seat of cataract which had been demonstrated by Rol- fink, Borel and others, was now confirmed by Brisseau; and Kepler had, by his discovery of the real use of the crystalline lens, proved the retina to be the true seat of vision, and had explained the mode in which glasses (in- vented three or four hundred years before) help the sight. It was in 1728 that Cheselden first succeeded in making an artificial pupil—an operation, the idea of which appears to have been previously suggested by Woolhouse, surgeon to James II. About the middle of the same century, Da- viel, a French surgeon, practised extraction through an incision of the cornea, as a regular method of removing cataract; while, a few years later, Pott adopted laceration of the capsule, and the breaking up of the lens as a dis- tinct mode of operating for cataract, independent of couch- ing. . , It thus appears, that the first grand improvements in oph- thalmic medicine and surgery were all made by English and French surgeons. Before the establishment of the ophthal- mic school of Vienna, ophthalmic medicine and surgery were in so low a state in Germany, that those who could afford it went to France to be operated on for cataract A complete revolution in this matter, however, has taken place since, and the Germans have far outstripped the French, and were fast outstripping the English surgeons, until the breaking out of the Egyptian ophthalmiain the army forcibly recalled the attention of the latter to the subject of eye- diseases. More recently, the French have begun to bestir themselves also. The ophthalmic school of Vienna, the establishment ot which, in 1773, forms an important era in the history of ophthalmic medicine and surgery, owes its celebrity in a meat measure to the labors of Professors Beer and John Adam Schmidt during the end of the last, and commence- ment of the present, century, the former at the General Infirmary, the latter at the Josephine Academy. Beer is distinguished for the accurate descriptions and histories of the diseases of the eye which he has given in his works, and by the great reputation which he acquired by his clinical lectures, which attracted students from all xxxu INTRODUCTION. quarters. His cotemporary, Schmidt, though less generally known than Beer, was superior to him, perhaps, in original- ity and genius. To John Adam Schmidt, ophthalmic medi- cine and Surgery are indebted for some most valuable con- tributions. He it was who gave the first correct account of iritis; for, strange as it may appear, surgeons were unacquainted with the real nature of that disease until the publication, in 1801, of his work on "Iritis and Secondary Cataract, occurring after Operations for Cataract."* In- deed, it may be said that we owe most of our knowledge of the internal inflammations of the eye to the Germans, though it must be confessed that they have occasionally refined too much in their distinctions. Since the establishment of the Ophthalmic School of Vienna, the ophthalmic clinic has become an essential part of the medical curriculum of every German university; and, indeed, the language of Germany is so interwoven with the literature of ophthalmic medicine and surgery, that he who would claim to be an authority in the latter must be well acquainted with the former. In Britain, ophthalmic medicine and surgery have always attracted a considerable share of attention. Indeed, Eng- lish surgeons have contributed as much to the real ad- vancement of ophthalmic medicine and surgery as those of any other nation. The establishment of Ophthalmic Institutions in London has been an example well followed up in other parts of the kingdom. I cannot forbear instancing, in particular, the Eye Infirmary of Glasgow, as being the source whence has emanated the standard work of Mackenzie. Until very recently, the school of Medicine of Paris, so famous for medical science in general, offered no adequate opportunity for the study of ophthalmic medicine and sur- gery, and French medical literature, so rich in other respects, boasted of no work of any merit on the subject. All this, however, is^changed now, from the labours of French sur- geons themselves, from those of Germans and Italians settled among them, and from the greater spread of information on the subject in the French language, through the medium of * Ueber Iritis und Nachstaar nach Staaroperationen. INTRODUCTION. XXX1U the Annates dWculistique of M. Cunier, established in Bel- gium, when the ravages of the Egyptian ophthalmia in the army of that country, some years ago, forced the import- ance of ophthalmic medicine and surgery strongly on public attention. LITERATURE OF OPHTHALMIC MEDICINE AND SURGERY. The subjoined is a list of the principal works on Oph- thalmic Medicine and Surgery in the English, German, and French languages. ENGLISH WORKS. W. Adams, Practical Observations on Diseases of the Eye, &c. London, 1814. G. J. Guthrie, Lectures on the Operative Surgery of the Eye. London, 1823. R. Hull, Cursory Notes on the Morbid Eye. London, 1840. W. La\#ence, A Treatise on the Diseases of the Eye. 2d Ed. London, 1841. S. Littell, A Manual of the Diseases of the Eye, &c. A reprint of an American work, Edited by H. Houston. Lon- don, 1840. . W. Mackenzie, A Practical Treatise on the Diseases ot the Eye. 3d Ed. London, 1840. R. Middlemore, A Treatise on the Diseases of the Eye. 2 vols. London, 1835. J. Morgan, Lectures on Disease of the Eye. London, 1839 J C Saunders, Treatise on some Practical Points relat- ing to the Diseases of the Eye. 2d Ed. London, 1816. B. Travers, A Synopsis of the Diseases of the Eye, and their Treatment. 3d Ed. 1823. F Tyrell A Practical Work on the Diseases ot the Eye, and 'their Treatment, Medically, Topically, and by Opera- tion. 2 vols. London, 1840. xxxiv INTRODUCTION. J. Vetch, A Practical Treatise on the Diseases of the Eye. London, 1820, J. Walker, Oculist's Vade-Mecum. Manchester, 1843. J. Wardrop, The Morbid Anatomy of the Human Eye. Vol. I. Edinburgh, 1808. Vol. II. London, 1818. A. Watson, A Compendium of the Diseases of the Human Eye. 2d Ed. Edinburgh, 1828. GERMAN WORKS. F. A. v. Ammon, Zeitschrift fur Ophthalmologic Dresden and Heidelberg, 1830—1837. F. A. v. Ammon, klinische Darstellungen der Krank- heiten und Bildungsfehler des menschlichen Auges, der Augenlider und der Thranenwerkzeuge, &c. Berlin, 1838. A. Andreae, Grundriss der gesammten Augenheilkunde. Magdeburg, 1837. K. I. Beck, Handbuch der Augenheilkunde. 2d Ed. Heidelberg, 1832. Beer, Lehre von den Augenkrankheiten. 2 vols, with colored plates. Vienna, 1813, 1817. M. J. Chelius, Handbuch der Augenheilkunflke, &c. 2 vols. Stuttgart, 1839 and 1843. F. Th. Fabini, Doctrina de morbis oculorum. 2d Ed. Pesth, 1831. J. N. Fischer, Klinischer Unterricht in der Augenheil- kunde. Prague, 1832. — v. Graefe und v. Walther's Journal der Chirurgie und Augenheilkunde. Berlin, 1820—1842.—Continued now as v. Walther und v. Ammon's Journal fiir Chirurgie und Augenheilkunde. K. Himly, Die Krankheiten und Missbildungen des menschlichen Auges und deren Heilung, &c. Leipzig-, 1843. J. C. Juengken, Die Lehre von den Augenkrankheiten 3d Ed. Berlin, 1842. A. Rosas, Handbuch der theoretischen und praktischen Augenheilkunde. 3 vols. Vienna, 1830. INTRODUCTION. XXXV A. Rosas, Lehre von den Augenkrankheiten. Vienna, 1834. C. G. F. Ruete, Lehrbuch der Ophthalmologic. Braun- schweig, 1845 and 1846. C. H. Weller, Die Krankheiten des menschlichen Auges, ein Handbuch fur angehende Aerzte, &c. 4th Ed. Berlin, 1830. FRENCH WORKS. Ch. J. F. Carron du Villards, Guide Pratique pour l'Etude et le Traitement des Maladies des Yeux. 2 vols. Paris, 1838. F. Cunier, Annales d'Oculistique. From 1838 to the present time. Brussels and Paris. A. P. Demours, Precis Theorique et Pratique sur les Maladies des Yeux. Paris, 1821. M. F. Rognetta, Traite Philosophique et Clinique d'Oph- thalmologie, base sur les principes de la Therapeutique Dynamique. Paris, 1844. Sanson, Lecons sur les Maladies des Yeux, faites a la Pitie, recueillies et publ. par J. B. Pigne. Paris, 1837. V. Stdber, Manuel Pratique d'Ophthalmologie ou Traite des Maladies des Yeux, Paris, 1834. Velpeau, Manuel Pratique des Maladies des Yeux, d'apres les Lecons Cliniques de M. le Prof. Velpeau, Chirurgien de l'Hopital de la Charite, par G. Jeanselme. Paris, 1840. AMERICAN WORKS. George Frick, M.D., A Treatise on the Diseases of the Eye; including the Doctrines and Practice of the most eminent modern surgeons, and particularly those of Pro- fessor Beer. Baltimore, 1823. William Clay Wallace, A Treatise on the Eye. Con- taining Discoveries of the Causes of near and far sighted- ness, and of the affections of the Retina, with remarks on XXXVI INTRODUCTION. the use of Medicines as substitutes for spectacles. Second Edition. New York, 1839. S. Littell, Jr., M. D., A Manual on the Diseases of the Eye; or, Treatise on Ophthalmology. Second Edition. Philada., 1846. Wm. Lawrence, F. R. S., A Treatise on the Diseases of the Eye. A reprint of an English work, Edited, with numerous Additions and Illustrations, by Isaac Hays, M. D. Philada., 1847. THE PRINCIPLES AND PRACTICE OF OPHTHALMIC MEDICINE AND SURGERY. CHAPTER I. Section I.—OPHTHALMOSCOPY, OR EXPLORATION OF THE EYES IN ORDER TO A DIAGNOSIS. § 1. This exploration is of two kinds, viz., subjective and objective. The subjective exploration of the eye comprehends an inquiry into the patient's sensations in the affected organ, such as pain, tolerance of light, and state of vision. The ob- jective exploration is directed towards the morbid conditions which admit of being perceived by the surgeon himself. A. SUBJECTIVE EXAMINATION OF THE EYES. a. Pain; its seat and character. 2. Pain, as if a foreign body were in the eye, with itchiness and' smarting of the edges of the eyelids, and sometimes pain across the forehead, indicates conjunctival inflammation. Rheu- matic pain, around the orbit, or in the temples, occurring in nocturnal paroxysms, points to inflammatory congestion of the sclerotica, as in iritis, &c. Deep-distending pain in the eyeball, with or without circumorbital or temporal pain, marks deep internal inflammation of the eye. b. Intolerance of light, or photophobia. 3. Intolerance of light, in a greater or less degree, is a very frequent symptom in the ophthalmia.; but that in which it occurs in the highest degree is the scrofulous ophthalmia of children. Intolerance of light may also occur in other affec- tions not coming under the head of the optehalmiae. 2 18 OBJECTIVE EXPLORATION OF THE EYES. c. State of vision. 4. Is the sight short (myopia), or long (presbyopia)? The pupil being greatly dilated, (mydriasis.) § 94, with indistinct- ness of vision, are objects seen more distinctly by looking through a small aperture in a card, blackened on the surface, held next the eye? Are objects seen distorted? Are they seen of another than their true colour, surrounded by a colored halo (chroopsia) ? Is vision dim ? if so, is it defective by day (day-blindness) ? or it is defective by night (night-blind- ness)? or it is defective both by day and night? Do the eyes soon become fatigued, and the vision confused, when near ob- jects are examined (asthenopia)? Are objects seen double (diplopia)? And if so, is the vision double when one eye only is used ? or is it double only when both eyes are used ? Is the half or a part of objects only seen (hemiopia, &c) ? Is there an appearance of motes or flies floating in the field of vision (muscse volitantes)? Do objects continue to appear before the eyes, but of an opposite tint or colour, for a few seconds after they are no longer looked at (ocular spectra) ? Are flashes and scintillations of light ever seen (photopsia)?— Such are the principal questions which may suggest themselves in the course of an inquiry into the state of vision. B. OBJECTIVE EXPLORATION OF THE EYES. 5. In this exploration, the eyes should be first examined without touching them. This it is of importance to do, espe- cially in inflammations, in order to avoid causing an increased determination of blood, lachrymation, &c, which in such cases are apt to be occasioned by the slightest touch, and which might complicate the appearance natural to the inflammation, and give an erroneous view of the nature of the case. In an hospital, the pupils should not, on any account, be permitted to touch the eyes of a patient, before the surgeon has made his examination. 6. The surgeon should, in succession, glance at the eye- brows and orbital margins, the eyelids and their movements, the borders of the eyelids and state of the eyelashes, and the corners of the eyes, and note the presence or absence of lachry- mation, the form and appearance of the eyeballs generally— their size and degree of prominence—movements and direc- tion—the correspondence of their axes; the appearance and colour of the white of the eye, the appearance of the cornea the colour of the iris, and the state of the pupil. EXPLORATION OF EYEBROWS, ETC. 19 7. Besides this direct examination of the eyes themselves, the general bearing of the patient, and the expression of his features should be carefully observed. The information thus obtained will sometimes reveal the nature of the case, or will guide in the further exploration of it. By the general bearing of the patient, and the expression of his features, it will be seen, for example, if he is affected with intolerance of light—if he be blind from amaurosis, or blind from cataract. 8. The patient, intolerant of light, keeps his head bent down, and covers his eyes with his hands, in order to protect them from the light. The eyelids are spasmodically closed, and at the same time the eyebrows are knit and depressed, and the cheeks drawn up, so that there is great distortion of the whole features. There is greater or less lachrymation. 9. Whilst the confirmedly amaurotic patient moves about with an air of uncertainty, his head erect, and the eyes wide open—not converged and fixed on any object, but staring for- ward as if on vacancy—perhaps moving about in a vacillating manner or squinting, the cataractous patient is more steady in his gait; and with his head bent forwards, his eyes half-closed, his eyebrows knit and depressed, he moves and directs the eyes naturally and steadily, in an exploratory manner. 10. This survey, constituting the first step in the objective exploration of the eye, may be taken during the time the patient is coming into the room, relating the history of his case, and describing his present sensations in the eyes. In the subse- quent steps of the objective exploration, attention should be carefully directed to the relations which may exist between the subjective and objective phenomena of the case. 11. Most probably the result of the preceding objective sur- vey, in conjunction with the subjective examination, will have been such as at once to direct the practitioner to the part affect- ed, on which he will accordingly fix his attention, and subject it to the necessary exploration in order to an exact diagnosis, not neglecting, however, to take a rapid, but methodical survey of the other parts of the eye, lest anything should be overlooked. The account of the mode of conducting the objective explora- tion of the different parts of the eye in detail, to which I now proceed, will necessarily include references to the principal morbid conditions of the organ. a. Exploration of the eyebrows, and orbital margins. 12. The affections of the eyebrows and orbital margins do not require much exploration for their diagnosis, a glance and 20 EXPLORATION OF EYELIDS, ETC. a few touches being in general sufficient, except in the case of a fistulous opening at the margin of the orbit, when it may be necessary to introduce a probe to ascertain the extent and di- rection of the fistula, and state of the bone. 13. In injuries and affections of the eyebrow and orbital margins, the eyelids are almost necessarily more or less im- plicated; and it is to be remarked, that in the case of blows, contusions and wounds of the eyebrow and margin of the orbit, there may have occurred injury of the fifth pair, concussion of the retina, or even of the brain, and as a consequence, amau- rosis. 14. In the exploration, attention is directed to the state of the skin all round the margin of the orbit, and of the hairs of the eyebrow. The skin may be the seat of an eruption, or of cicatrices. The hairs may have fallen off, or they may be the seat of phtheiriasis. Tumours will not unfrequently come under notice in the eyebrows, or connected with the margin of the orbit. The injuries met with are burns, from which the eyelids in general suffer most; contusions and wounds with ecchymosis. 15. The affections found more particularly seated in the margin of the orbit, besides fracture, &c, which may compli- cate the injuries just referred to, are inflammation and abscess, involving the periosteum and bone. Abscess manifests itself _ by a dark red swelling, which at last bursts and discharges a thin or curdy matter. The carious or necrosed bone is felt bare and rough, on the introduction of a probe thr6ugh the opening, now become fistulous. Lastly, the margin of the orbit may be thickened from periostosis, or hyperostosis, or be the seat of an exostosis, or of an osteo-sarcomatous tumour. b. Exploration of the eyelids and their tarsal border, includ- . ing the state of the cilia and Meibomian apertures. 16. The points to be noticed in regard to the eyelids, are, first, their position, their connections, and their movements; then their organic condition generally, and that of their tarsal border in particular; the direction of the eyelashes, the state of the Meibomian apertures, and of the Meibomian discharge, as indicated by the presence or absence of incrustation of the eye- lashes. 17. The morbid changes in position, which the eyelids may be found to present, are, eversion or ectropium, inversion or entropium, retraction and shortening or lagophthalmus. The morbid connections are, adhesion to each other's edges, EXPLORATION OF EYELIDS, ETC. 21 or ankyloblepharon, which may be either mediate or imme- diate, total or partial, congenital or accidental; and adhesion of the inner surface of one or both eyelids to the globe, or sym- blepharon, which may likewise be mediate or immediate, total or partial. 18. In proceeding to indicate the morbid changes which the movements of the eyelids may present, it may be useful to premise that it is chiefly by the movements of the upper eye- lid that the open or closed state of the eye is produced. The upper eyelid is both vertically and horizontally larger than the lower, and in the closed state during sleep covers much more of the front of the eyeball; but in voluntary or forced closure of the eye, the lower eyelid is drawn up, being at the same time impressed with a horizontal movement towards the inner angle, by the action of the orbicularis palpebrarum muscle, and meets the upper lid half-way. Or, if the upper lid be im- movably retracted under the edge of the orbit, either by dis- ease, or by the finger for the sake of experiment, the lower eyelid can of itself almost entirely cover the whole front of the eyeball. When the action of the orbicularis ceases, the lower eyelid falls back into its former state by its own elasticity and that of the skin of the cheek. It is by the levator palpebral, that the open state of the upper eyelid is maintained. In winking, the upper eyelid falls and the lower rises considera- bly, in consequence of the momentary action of the orbicularis. 19. Nictitation may be observed to be morbidly frequent. The eyelids may be affected with a twitching or quivering mo- tion, which is, however, sometimes so slight as not to be very apparent to the observer, though felt by the patient himself to be very annoying. Or, they may be spasmodically closed in- termittently, or remittently, or continuously,—a symptom usu- ally of the presence of a foreign particle in the eye, inflamma- tion of the conjunctiva, or of intolerance of light. 20. The movements again may be defective, or lost from paralysis. There may be a constant open state of the eye, from palsy of the orbicularis muscle. Or, the upper eyelid may hang down over the eye from palsy or atony of the levator palpebrae superioris—paralytic ptosis. In the former case, there will probably be found palsy of the other muscles of the same side of the face; in the latter, there will probably be found, on raising the eyelid with the finger, dilatation of the pu- pil, and the eyeball more or less fixed, and turned towards the temple from concomitant paralysis of those muscles of the 22 EXPLORATION OF EYELIDS, ETC. eyeball which, in common with the levator palpebrae, are sup- plied by the third pair of nerves. 21. The eyelids may be the subject of various injuries, such as burns and scalds; contusions with ecchymosis, wounds in- cised or lacerated, or poisoned, as by the stings of the scorpion, wasp, &c. 22. The eyelids are sometimes the original and principal seat of erysipelas. In erysipelas of the face they are always involved. They may be the seat of phlegmonous inflam- mation, in which case, the redness, which is intense, and swell- ing are circumscribed, and the part very painful to the touch. Sometimes they present black sloughs from gangrenous inflam- mation. Both erysipelatous and phlegmonous inflammation of the eyelids are to be distinguished from the sympathetic in- flammatory oedema of these parts, which attends some of the inflammations of the eye, especially the purulent inflammations of the conjunctiva. 23. The eyelids are often simply cedematous, sometimes emphysematous. 24. In children the eyelids are often the seat of porrigo lar- valis. 25. The eyelids may be the seat of syphilitic ulcerations. In infants affected with syphilis, the eyelids, and other parts of the face and body, are covered with an eruption of flat broad pustules which break, scab, and spread. Such children have a peculiarly wrinkled and withered expression of face. 26. The eyelids may be the seat of narvus maternus, of warts, and of different kinds of tumours. Lastly they may be found cancerous. 27. In regard to the tarsal borders of the eyelids, it is to be premised that they are broad surfaces. The border of the upper eyelid is about one-twelfth of an inch broad; that of the lower about one-fifteenth. The edge bounding the border anteriorly corresponds to the insertion of the eyelashes, and is round. The posterior edge is much 'sharper and more defined than the preceding, and is the place where the delicate integu- ment of the border of the eyelid is continued into the palpebral conjunctiva. On the border of either eyelid between the two edges or boundaries just described, but nearer the posterior than the anterior, and parallel to them, there is observable, on close inspection, a row of minute pores—the excretory mouths of the Meibomian follicles. Fig. 1. 28. The tarsal border of the eyelids may be found inflamed— perhaps ulcerated—(ophthalmia tarsi,) in which case, the eye- EXPLORATION OF EYELIDS, ETC. 23 " lashes will be incrusted partly with dried Meibomian discharge, partly with the discharge from the ulcers. Hordeolum or stye is another form of inflammation at the free margin of the eye- lids. Inflammation and abscess of the Meibomian follicles simulate the appearance of stye externally, but are rarer oc- currences. The eyelids at their edges or close to their edges may present small tumours, thickening, and callosity, unattended by any great degree of inflammation, viz., grando, chalazion, tylosis, &c. 29. The eyelashes are sometimes the seat of phtheiriasis, which is apt to be overlooked, except a close examination be made. Madarosis, or loss of the eyelashes, is at once recog- nized. 30. The eyelashes are often found in greater or less numbers directed against and irritating the eyeball, constituting trichiasis and distichiasis. The surgeon should always take particular care to assure himself therefore of the direction of the eye- lashes ; and in order to do so, and to see properly the broad surface of the tarsal border, and the state of the Meibomian apertures, the eyelids should be slightly everted by gentle pres- sure with the point of the finger on the skin of the eyelid, the evelashes being kept between the finger and the skin. "31. By this means it will generally be at once seen if any of the eyelashes are growing in against the eyeball. Sometimes, however, such eyelashes are so pale and fine that they are apt to escape notice. The presence of these may be detected by attention to the following point when they might otherwise be overlooked:—the tears, of which there are in such cases gene- rally more than usual, rise up around the pale mis-directed eyelashes, and between the eyelid and eyeball, by capillary attraction, and occasion a marked reflection of the light at the place. 32. One or more of the Meibomian apertures may become covered with a thin film apparently of epidermis which prevents the escape of the secretion, so that the latter accumulates and raises the film up into a small elevation like a phlyctenula. The Meibomian discharge, is increased, whenever there is any irritation of the edges of the eyelids, and especially of the pal- pebral conjunctiva. ...... 33 The posterior edge of the tarsal border, which is in its natur'al state sharply defined, may be found rounded or oblite- rated in consequence of chronic inflammation of the palpebral conjunctiva and of the integument of the tarsal border. In such 24 EXPLORATION OF CONJUNCTIVA, ETC. cases, as no Meibomian secretion can be pressed out, it would seem that the Meibomian apertures are obliterated. c. Exploration of the conjunctival surface of the eyelids, and of the palpebral sinuses. 34. The lower eyelid is readily everted for the purpose of examining its inner surface, by simply drawing down the skin of the lid and cheek; and in order that the lower palpebral sinus may be fully exposed, the patient is to be desired to turn the eyeball upwards, while the lower eyelid is thus held drawn down and everted. 35. The upper eyelid does not admit of being so readily everted as the lower; and as the operation is attended with some uneasiness to the patient, it ought not to be had recourse to unless the glimpse of the inner surface of the eyelid, which may be obtained by raising the upper eyelid, and drawing it slightly from contact with the eyeball by pressing up the skin of the eyebrow and eyelid itself, prove insufficient to satisfy the surgeon of the state of parts. If there is reason to suppose that a foreign body is lodged under the eyelid, then eversion is the only means of detecting and removing it. 36. In order to evert the upper eyelid, lay hold of the eye- lashes between the forefinger and thumb of the left hand, for the right eye—and vice versa—in such a way, that whilst the eyelashes are securely held, the points of the thumb and fore- finger may extend a little beyond their insertion, so that the former may be applied to the broad border, and the latter to the outer surface of the eyelid. Having thus got a secure hold of the eyelid, draw it away from its contact with the eyeball, and then, whilst applying counter pressure downwards on the outer surface of the eyelid, opposite the orbital margin of the tarsal cartilage, raise the ciliary margin upwards. The counter pres- sure may be applied either by the thumb of the free hand, or what most people find better adapted to the purpose, by a thick probe. 37. The whole extent of the upper palpebral sinus cannot be exposed like the lower. To explore it a probe must be used, whilst the everted lid is kept as much as possible with- drawn from the eyeball, and the patient is directed to turn the eyeball downwards. 38. By everting the eyelids, the state of the palpebral conjunctiva is ascertained; whether it be inflamed or granular and whether there be growths connected with or projecting at the inner surface of the eyelids, as chalazia. By the eversion EXPLORATION OF LACHRYMAL ORGANS. 25 of the eyelids, also, foreign bodies in the eye are readily detect- ed and removed. Small particles are especially apt to adhere to the inner surface of the upper eyelid. d. Exploration of the angles of the eye, and of the lachrymal organs as regards their general state. 39. The inner and outer corners of the eye, where the eyelids join, are called canfhi. The outer canthus, generally speaking, forms an acute angle; but on close examination, it is observed that the apex is rounded off, somewhat prolonged and turned slightly downwards. The conformation of the inner canthus is altogether peculiar and rather complicated. At the inner canthus, the palpebral fissure is prolonged into a secondary fissure, the borders of which being destitute of cartilage, are not firm and square, but soft and rounded. The secondary fissure is closed by the action of the orbicularis muscle at the same time as the eyelids. The space within the inner or nasal canthus is called lacus lachrymalis. 40. The state of the outer canthus is readily ascertained by slightly drawing the eyelids from each other. The most ordi- nary morbid condition met with there, is abrasion or ulceration of the skin. Sometimes there is eversion—sometimes inver- sion. Fig. l. Fig. 1.—An eye, with the eyelida divided vertically, and the outer halves everted, to show the orifices of the ducts of the lachrymal gland, into which hairs are inserted. The letters a and b indicate respectively the upper and the lower puncta lachrymalia. Along the border of the eyelids are observed the Meibomian apertures. 41. The parts situated at the inner canthus are exposed, by drawing the eyelids from each other, and at the same time 26 EXPLORATION OF LACHRYMAL ORGANS. slightly everting them. At the inner extremity of the border of either eyelid, where the fissure of the nasal canthus begins, the small papillary eminence called lachrymal papilla is seen, with the small orifice in its summit called lachrymal point, of such a size as to admit a thick bristle. These lachrymal points are, from their size and situation, sufficiently conspicuous not to be confounded with a Meibomian aperture. In the natural state, the lachrymal papilla, are inclined towards the lacus lachry- malis. The lower papilla is somewhat more prominent than the upper, and situated somewhat more towards the temple. At the bottom of the lacus lachrymalis, is the lachrymal carun- cle, and between it and the white of the eye, the semilunai fold. The semilunar fold and lachrymal caruncle may be found swoln and enlarged, (encanthis inflammatoria;) some- times the seat of growths, (encanthis funagosa.) 42. In reference to the exploration of the state of the secret- ing lachrymal organs, it is to be remembered that the lachrymal gland consists of two masses, an upper and a lower. The for- mer is that which lies in the lachrymal fossa of the frontal bone; the latter, composed of a loosely connected aggregation of small lobules, extends from the upper mass down to the outer part of the upper margin of the tarsal cartilage of the upper eyelid, in the substance of which it lies at the outer part, and may be seen shining through the conjunctiva on everting the upper eyelid. The ducts of the lachrymal gland are some twelve in number, very slender, and open by as many minute orifices on the surface of the conjunctiva, lining the inside of the upper eyelid, arranged in a row, extending from the outer canthus inwards for about half an inch, and parallel to, but a little above, the outer part of the upper margin of the tarsal cartilage. Fig. 1. 43. In exploring the derivative lachrymal organs, the appear- ance of the region of the lachrymal sac should be particularly noted. If, with watery eye, there are marked redness, circum- scribed swelling, and pain even on the slightest touch, the case is one of acute dacryocystitis. If there is less marked redness, merely unnatural fullness, with pain only on pressure, and when pressure is made, if there takes place regurgitation of tears with puriform mucus, through the puncta, the case is one of chronic dacryocystitis. If there is a large livid indolent tumour, more or less hard, pressure on which does not cause any evacuation of matter either through the puncta or into the nose, the case is one of mucocele. If there is a large flaccid tumour without pain, much or any redness, readily yielding to the pressure of EXPLORATION OF FRONT OF EYEBALL. 27 the finger; and if on that pressure a mucous matter is evacuated through the puncta, but especially into the nose, the case is one of relaxation of the lachrymal sac. Lastly, if there is a fistulous opening leading into the sac, the case is one of fistula of the lachrymal sac. 44. The state and position of the lachrymal papillae and puncta should next be examined. 45. In addition to the examination now detailed, instrumental exploration of the derivative lachrymal passages may in certain cases be required, to determine the nature and seat of obstruc- tion. But for this, see under the head of diseases of the lach- rymal organs. 46. The state of the lachrymal discharge is to be noted. If the eye is overflowing in tears, it is to be determined whether this is owing to increased discharge from the gland—epi- phora—or to diminished or obstructed derivation of the tears towards the nose—stillicidium lachrymarum. The point is determined by ascertaining the state of the derivative apparatus. If this is free from disease, the case is one of epiphora; if not, it is one of stillicidium. It is, however, to be observed, that stillicidium and epiphora may co-exist. e. Examination of the direction and movements of the eye- balls. 47. Both eyes may be affected with squint, though one only appears to be so. To determine this, in the case of convergent squint, for example, cover the eye which appears well directed, by holding the hand before it, and direct the patient to look straight before him with the previously distorted eye. While he is doing this, look behind the hand at the other eye, and if it now be seen to be distorted, there is double squint; if on the contrary it remains straight, it is not affected, but the squint is confined to the one eye alone. 48. A partial rotatory movement of the eyeball to and fro on its antero-posterior axis (oscillation) may be met with; or a movement from side to side—(nystagmus.) f. Examination of the front and interior of the eyeball. 49. The circumstances to be noted in this examination are, the state of the white of the eye, that is, of the ocular conjunc- tiva, and of the sclerotica, including the expansion of the ten- dons of the recti muscles underneath, the state of the cornea, the state of the iris and pupil, the state of the aqueous chambers and humour, the presence or absence of opacity behind the 28 EXPLORATION OF FRONT OF EYEBALL. pupil; and lastly, the degree of prominence and consistence of the eyeball. 50. Mode of exposing the front of the eyeball for examina- tion.—The patient should be seated before a window, in such a way that the light falls obliquely on the eye to be examined, from the temporal side, whilst the surgeon, placed before the patient, applies the pulp of his thumb on the skin of the upper eyelid, previously well dried, near its ciliary margin, whilst it is gently closed, and raises it by traction of the skin. In doing this, no pressure should be made on the eyeball, but the skin of the raised eyelid may be secured by pressure against the margin of the orbit. The lower eyelid is to be depressed to the extent that is necessary in a similar way, by the fore or middle finger of the other hand. In separating the two eyelids, however, it is to be remembered that when the upper is much raised, the lower should not be much depressed; and when the lower is much depressed, the upper should not be much raised, in order to avoid putting the external commissure too much on the stretch. 51. The eyelids being thus opened, the surgeon can look directly into the eye, or from any one side, by requesting the patient to move the eye in different directions. 52. To avoid irritating the eye too much, the eyelids should not be kept more than a few seconds separated at a time; they should be occasionally allowed to close, and after a few seconds, re-opened when the examination requires to be prolonged. 53. In exploring the state of the interior of the eye, illumi- nation greater than is afforded by the window merely, is some- times necessary. In this case, the light is thrown concentratedly into the eye by means of a convex lens, about two inches in diameter, and three or four inches focus. 54. For the examination of the eyes in children, especially when affected with intolerance of light and blepharospasmus, considerable management is required, and even some degree of gentle force. 55. The surgeon is to seat himself on a chair, with a towel folded longways, laid across his knees. On another chair, on the surgeon's left hand, and a little in front of him, the nurse, with the child, sits in such a way that when she lays the child across her lap, its head may be received on the towel, and be- tween the knees of the surgeon, and thus held steadily. The nurse now confines the arms and hands of the child, whilst the surgeon, having dried the eyelids with a soft linen cloth, pro- ceeds to separate them by applying the point-of the forefinger STATE OF OCULAR CONJUNCTIVA. 29 of one hand to the border of the upper eyelid, and the point of the thumb of the other hand to the border of the lower, and then sliding them against the eyeball, but without pressing on it, towards their respective orbital edges. This mode of pro- ceeding obviates the eversion of the eyelids, which is so apt to take place under the circumstances. The eyelids being thus opened, they are readily kept so during the examination, by the command which the points of the finger and thumb, resting against the edges of the orbit, have of their borders. 56. By this means the whole front of the eyeball is exposed, but it often happens that, to avoid the light, the eye is spasmo- dically turned up, so that the cornea is in a great measure con- cealed. By waiting a few seconds, however, enough of it will in general come into view to enable the surgeon to judge of the state in which the eye is. Having completed this part of the exploration, there is not much difficulty in so everting the eye- lids as to ascertain the state of the palpebral conjunctiva. 57. State of the white of the eye—ocular conjunctiva.— The ocular conjunctiva is connected to the sclerotica underneath by cellular tissue loose enough to allow the former to slide somewhat upon the latter. At the margin of the cornea the cellulo-vascular and nervous basis of the sclerotic conjunctiva stops—what of the conjunctiva extends over the cornea being reduced to the epithelium. This epithelium, however, forms a thicker layer than on the sclerotic conjunctiva. It is, of course, intimatelv adherent to the proper substance of the cornea. 58. The blood-vessels of the ocular conjunctiva ramify in a direction from the circumference of the eyeball towards the cornea, and form a vascular circle or wreath around it, but send no vessels in the healthy state into it. Except the ramifications derived from the seven recto-muscular vessels, which are often enlarged and varicose, the vessels of the ocular conjunctiva cannot be seen except in the inflamed state of the membrane. 59. The presence or absence of redness is a point which should be first noted in exploring the state of the ocular con- junctiva. If there is redness, it is easy to determine whether it is the redness of ecchymosis or the redness of inflammatory congestion. The redness of ecchymosis is dark and occurs in patches, abruptly defined, without any appearance of vascular ramifications: whilst the redness of inflammatory congestion presents contrary characters, as will be detailed in their proper places. The ocular conjunctiva maybe the seat of an aphthous eruption, or of growths of various kinds, such as pterygium, Pinguecula, warts, fungus, trichosis, and the like. It may be 30 STATE OF SCLEROTICA. found stained from the long-continued use of nitrate of silver drops, &c. 60. The cellular tissue between the conjunctiva and scle- rotica is sometimes the seat of extravasations of blood, subcon- junctival ecchymosis, sometimes the seat of an accumulation of serous fluid, as in the oedema attending erysipelatous ophthal- mia. It is sometimes the seat of a more serious form of oedema, that known by the name of chemosis, and common in the purulent inflammations of the conjunctiva. It may also be the seat of emphysema, and is occasionally so of phlegmon. 61. State of the white of the eye—sclerotica, including the tunica tendinea, or expansion of the tendons of the recti muscles.—In the natural state, the sclerotica, including the tunica tendinea, is white and glistening, like other fibrous membranes. The peculiar appearance of the white of the eye is owing to its shining through the semi-transparent conjunctiva. The bluish tinge of the white of the eye in childhood is owing to the thin- ness of the sclerotica at that time of life, allowing the dark choroid to shine through. 62. In the healthy state, the sclerotica is even more bloodless than the conjunctiva. The blood-vessels seen in it in certain inflammations are very minute, and converge in straight lines towards the margin of the cornea. Opposite the insertion of the ciliary ligament, some of these vessels pierce the sclerotica to gain the interior of the eye, where they join the vessels of the iris; whilst others anastomose with the circumcorneal ves- sels of the conjunctiva. Fig. 2. STATE OF CORNEA. 31 63. If the white of the eye is red from inflammatory con- gestion, it becomes a question whether the congestion be in the conjunctiva or sclerotica.—In conjunctival inflammation, the vessel's of the sclerotic conjunctiva are large, somewhat tortuous, and arranged in a reticular manner; the colour is scarlet, or brick red, and it may be deeper towards the orbit, but more or less shaded off towards the cornea. In sclerotic injection, the redness is in the form of a pink or lake-colored zone, encircling the cornea; the injected vessels being very minute, and disposed in straight radiating lines, as if from its margin, where the tint is deeper, whilst it is shaded off, and disappears towards the orbit, the converse of what occurs in the injection attending conjunctival inflammation. The seat of the injected vessels, whether in the sclerotic conjunctiva or in or on the sclerotica it- self, is easily proved, supposing any doubt exists, by making the conjunctiva slide on the sclerotica, when the vessels, if seated in the conjunctiva, will be observed to move along with it, whereas, if seated in the sclerotica, or closely applied to its surface, they will remain stationary. When both conjunctiva and scle- rotica are injected at the same time, the pink hair-like vessels of the sclerotica are seen stationary through the larger meshes of the sliding conjunctiva. But when the conjunctiva is very much injected, the state of the sclerotica cannot be seen. 64. Tumours on the white of the eye are to be examined as to whether they have their seat in the conjunctiva only, or have their roots in the sclerotica. A part of the sclerotica may be found unnaturally prominent, and bluish-black—sclero- tic staphyloma. 65. State of the cornea.—The prominence and breadth of the cornea, the state of its margin, its connection with the sclerotica, and its transparency and non-vascularity* in the mature and healthy state, as also its relations to the iris, and its composition of three principal layers of different tissue, viz., the proper substance, forming its principal thickness; the thick epithelium, or conjunctival layer, on its anterior surface; and the membrane of Descemet, on its posterior surface, are cir- cumstances to be had in remembrance in examining whether it be the seat of disease. 66. In order to ascertain the prominence of the cornea, a profile examination of it should always be made. The cornea may be found unnaturally prominent; the prominence may be spherical, as in corneitis, or conical, as in conical cornea. * The cornea is nourished by transudation from the vessels forming the conjunctival and sclerotic circumcorneal zones. 32 STATE OF MARGIN OF CORNEA. Besides these unnatural states of prominence, in which the transparency of the cornea is usually still more or less retained, there is the opaque prominence of staphyloma, which may be either partial or complete. The cornea may be found unnatu- rally flat. By a profile examination, also, it will be seen in any doubtful case whether an opacity is seated in the cornea or not. Facets and small ulcers of the cornea will also be detected. 67. The usual diameter of the cornea is 9-20ths of an inch transversely, somewhat less vertically, the outline of the cornea not being quite circular, but rather oval, and this is the literal sense; its small end being that next the temple. Any morbid increase or diminution of diameter which the cornea may pre- sent, is usually an accompaniment of increase or diminution in the size of the eyeball generally. 68. State of margin of the cornea.—Externally the sclero- tica overlaps, or encroaches more or less on the edge of the cor- nea. In certain constitutions, and especially in old persons,* the overlapping part of the sclerotica is thicker and more opaque than usual—perhaps also encroaching more extensively on the cornea. The conjunctiva covering the overlapping sclerotica, especially when the latter is to any considerable extent, is like the sclerotic conjunctiva generally, composed of both chorion and epithelium; and although it adheres to the subjacent over- lapping part of the sclerotica very closely by cellular tissue, it by no means presents the same intimate union with the subja- cent structure which the extension of conjunctival epithelium over the transparent cornea does. The conjunctiva covering the overlapping part of the sclerotica has a vascular connection with the latter, no otherwise than by the anastomoses of the proper vessels of each—a vascular connection, which indeed subsists between the sclerotica and conjunctiva elsewhere. The disposition just described is connected with a point in the pathology of the eye, viz., the bluish-white ring which is ob- served to encircle the cornea more or less completely in certain internal inflammations of the eye, and so frequently in what is called arthritic iritis, that it has been considered a diagnostic of it, but certainly without just grounds. 69. In reference to the cause of the appearance, it is to be remembered that the insertion of the ciliary ligament is at some little distance from the apparent margin of the cornea; that the vessels which form the red zone of the sclerotica in the internal inflammations of the eye, and in inflammation of the proper substance of the cornea, are vessels which send branches in- * The arcus senilis is not here referred to. OPACITIES, ETC., OF CORNEA. 33 wards to the iris, opposite the ciliary ligament, branches out- wards to anastomose with those of the conjunctiva, and lastly, branches which, following the original direction, go to be con- tinued into those newly developed in the proper substance of the cornea. These vessels are not apparent in the healthy state, and one set of them only may become apparent in in- flammation. Thus, in inflammation of the iris, they will be apparent only as far as opposite the insertion of the ciliary liga- ment. Between this and the clear part of the cornea, is the opaque overlapping part of the sclerotica, which of course, not being in the way of the progress of the vessels towards the in- flamed part, remains white as usual; and the cornea not being affected, there are no vessels developed in its proper substance. Hence the overlapping part of the sclerotica is seen in contrast between the abruptly terminating red sclerotic zone, on the one hand, and the transparent cornea, (appearing dark on account of the dark structure behind it,) on the other, and forms the bluish-white ring. 70. From this explanation, the bluish-white ring round the cornea ought to exist more or less in all internal inflammations of the eye, unless obscured by vascularity of the conjunctiva in inflammation of the cornea. So it does; but in persons of otherwise sound constitution, and not of advanced age, the overlapping sclerotica is so transparent, and sometimes also so narrow, that it is not strongly contrasted by the transparent cornea. It is otherwise, however, in certain persons, espe- cially such as are advanced in life, in whom the encroachment of the sclerotica and fully developed conjunctiva on the cornea exists to a great degree, and in a very opaque state; the bluish- white ring then appears in the exaggerated distinctness which has commonly attracted the notice of surgeons. 71. The condition of the eye necessary for the distinct ap- pearance of the bluish-white ring round the cornea, occurring principally in old persons of bad constitution, and these being the very persons in whom an internal inflammation of the eye very often presents what is called the arthritic character, are circumstances which readily explain the error of supposing the bluish-white ring round the cornea diagnostical of arthritic iritis. . 72. In degeneration of the structure ot the cornea, the limit between its margin and the sclerotica may be quite obliterated. 73. The changes in the transparency which the cornea may present, are very various in seat, degree, extent, and nature. As regards seat, they are distinguished according to the different 3 34 STATE OF THE ANTERIOR CHAMBER, ETC. layers of the cornea which they implicate. But as regards na- ture especially, they are to be distinguished into those in which opacity is for the time merely a secondary consideration in the case, viz., phlyctenular, pustules, abscesses, and ulcers, which are concomitants of inflammation, and those in which the opacity, whether removable or not, is now the principal defect, viz., opacities properly so called. 74. A foreign body adhering to the cornea may simulate an opacity. 75. Minute opacities of the cornea, otherwise previously not very evident, are brought into view when the pupil is di- lated, being rendered distinct by contrast with the black back- ground formed by the pupil. 76. When in its mature state, vessels are observed in the cornea; they are new formations developed from the lymph exuded into its substance, from the vessels, in a state of in- flammatory congestion, of the adjoining conjunctival or sclerotic circumcorneal zone. New vessels may be observed:—1, be- tween the epithelium and proper substance; 2, in the proper substance; 3, between the proper substance and membrane of Descemet—these being the situations where lymph is exuded in inflammation. 77. Foreign bodies getting into the eye, especially when projected with force, may adhere to or become imbedded in the cornea. The cornea is subject to be variously injured by me- chanical or chemical agents. Certain chemical agents, such as mineral acids and lime, have the effect of rendering the epithe- lium of the cornea, in common with that of the conjunctiva, white and opaque, and causing it to become detached, and to peel off from the proper substance of the membrane. 78. The relation between the iris and cornea should not be passed unnoticed in reviewing the state of* the cornea. When the cornea is penetrated by ulcer or wound, the aqueous hu- mour escapes, and the iris is apt to be prolapsed. Of this prolapsus iridis there may be different degrees, according to the extent of destruction of the cornea; and as effects of differ- ent degrees of former prolapsus, there may be found synechia anterior, partial staphyloma, total staphyloma. 79. The cornea may be the seat of growths and tumours. 80. State of the anterior chamber, and aqueous humour.— The size and form of the anterior chamber are determined by the diameter and state of prominence of the cornea, on the one hand, and the position of the iris on the other—whether the STATE OF THE IRIS AND PUPIL. 35 latter inclines forwards to, or backwards from, the cornea- circumstances to be determined by examining the eye from the side. (s. 85.) 81. The state of the aqueous humour is next to be attended to—whether it is of natural transparency, or whether it be mixed with any foreign matters, in the form of lymph, pus, or blood. 82. State of the iris and pupil.—The colour, striated aspect, and position of the iris, and the state of the pupillary margin, are the points first to be noted; then the form, size, and espe- cially the motions of the pupil. 83. When the iris is inflamed, its colour is changed—if blue, to green; if brown, to reddish brown; and the striated appearance of its surface becomes indistinct, and its brilliancy impaired. In syphilitic iritis, its pupillary margin presents a tawny colour. Change of the colour of the iris may also fol- low an injury of the eye; but it is sometimes met with in cases in which it is alleged there has been no preceding inflammation, or any other apparent cause. In the cases referred to, how- ever, the change of colour is attended with some impairment of the sensibility of the retina, or with cataract, indicating that there is something wrong about the nutrition of the eye—pro- bably slow inflammation. 84. Sometimes dark spots are observed on the iris, looking as if its proper substance were at the place gone, and the uvea appearing, or even protruding through. Somewhat similar spots may be met with in healthy eyes; but the spots here referred to are met with, and sometimes very large, after long- continued unhealthy inflammation of the iris, syphilitic, arthritic, or cachectic. In such cases, the pupillary margin is adherent to the lens, and the middle of the iris projects towards the cornea. The proper substance of the iris, which remains evident, is much changed in colour, and presents a remarkable fibrous appearance. This change in the structure of the iris is called iridoncosis, or staphyloma uvese, being supposed to be a protrusion of the uvea through the proper substance of the iris. 85 In its natural state, the iris is plane, neither inclining back towards the lens, nor forwards towards the cornea. Sometimes it is met with, in consequence of different morbid states of the eye, inclined towards the cornea. A. deceptive appearance of this often occurs, if the eye be viewed from the front only; but all doubt is avoided by looking at it in profile. If the iris still retains its natural planeness, the pupil will be seen 36 STATE OF THE IRIS AND PUPIL. nearer the margin of the iris which is next the observer, thus:— Fig. 3. Whereas, if the iris be inclined towards the cornea, the pupil will be seen towards the opposite margin, thus :*—Fig. 4. 86. Sometimes the iris is inclined back from the cornea, being concave forwards, instead, as in the preceding case, convex. Sometimes, and especially in the cases just mentioned, the iris is seen to be tremulous—to shake on every motion of the eye, which indicates a dissolved state of the vitreous humour. 87. Besides other changes in the pupillary margin, such as the tawny colour in syphilitic iritis, thickening, a fringed appear- ance, &c, there may be, adhesion of it to the capsule of the lens (synechia posterior), producing distortion, contraction, and diminution in the mobility of the pupil. Analogous changes in the state of the pupil may be produced by other causes, but that they are owing to morbid adhesions will, in general, be observed, on careful examination, and very certainly if bella- donna be applied: for by this the free parts of the margin of the pupil will be dilated, and the adhesions rendered very evi- dent, whilst the distortion of the pupil will be much increased. 88. The iris may be adherent by some part of the cornea, synechia anterior, or partial staphyloma, according to the extent of the iris and cornea implicated, and the consequent presence or absence of prominence at the place. In this case also the pupil is found distorted, contracted, and more or less confined in its motions. These changes are readily detected, especially by viewing the eye from the side, and by the use of belladonna. * It is curious to see how very generally artists, in representing the eye in profile, have committed the error of drawing the pupil as it appears only when the iris is unnaturally inclined towards the cornea. Another common mistake in profiles of the eye is the monstrous size of the palpebral fissure. C0L0B0MA IRIDIS. 37 89. The pupil may be found completely closed, and this state may be either simple or complicated, with morbid adhe- sions, &c. 90. Excrescences or tumours sometimes present themselves connected with the iris. 91. The deviations in the form, size, and especially the mo- tions of the pupil, now to be noticed, are such as are independ- ent of morbid adhesions. 92. Mode of examining the state of the pupil—-The pa- tient is to be seated opposite the light. The surgeon, standing or sitting before him, closes both the patient's eyes by bringing down the upper eyelids. These he rubs over the cornea with his thumbs, and then suddenly opens one eye to the light, and carefully notices how far the pupil was dilated, and how quickly it contracts on exposure to the light. Both eyes are again to be closed and rubbed in the same way, and then the other eye suddenly opened and examined/ 93. If the surgeon were to examine both pupils at the same time, by unshading both eyes simultaneously, a mistake might be committed, as the pupil of a blind eye may move in concert with that of the other which is sound. But when the move- ments of the pupil of the latter are prevented by its being shaded, the pupil of the former will in general be found to be quite unaffected by the light. 94. The pupil may be found much dilated, and either slug- gish in its movements, or altogether immovable; or, it may be contracted, and either sluggish or immovable. In these cases which are respectively named mydriasis (4) and myosis, there may be no other disturbance of vision than what the state of the pupil will account for, or there may be amaurotic defect of vision. 95 Changes in form or position of the pupil, not owing to morbid adhesions, are sometimes met with in syphilitic iritis, arthritic iritis, choroiditis, amaurosis,—a result probably of some affection of the ciliary or iridal nerves. 96 In consequence of blows, &c, the ins may be detached at some part of its ciliary circumference, the result of which is a false pupil. . , . . 97 Coloboma iridis, which consists of a Assure in the ins extending from the pupil towards the ciliary margin of the iris, is sometimes met with, either as a congenital malformation or as the result of injury. .... t u ,, 98 Congenital absence of the ins sometimes presents itself. It is readily distinguished by the uniform dark, though not 38 OPAQUE APPEARANCE BEHIND THE PUPIL, ETC. black appearance, behind the cornea ;* unless cataract has form- ed, which is, in general, sooner or later the case. If cataract has formed, the opaque lens is seen to its very circumference. 99. Exploration of opaque appearances behind the pupil.— Though the nature and seat of an opaque appearance behind the pupil may be, to a certain extent, determined by the expe- rienced surgeon, without artificial dilatation of the pupil, it is always advisable, especially for the young surgeon, not to pro- nounce a formal opinion of the exact nature and seat of the opaque appearance behind the pupil in any case, until after an examination has been made with the pupil dilated. 100. Artificial dilatation of the pupil.—The dilatation of the pupil by belladonna or hyoscyamus, besides its use in the treatment of the internal ophthalmia., is a most valuable means of exploring the state of the pupil and the pupillary margin of the iris, as above shown, and also of exploring the nature and seat of opaque appearances behind the pupil. 101. The action of belladonna is stronger than that of hyos- cyamus. They are usually applied either in the form of ex- tract, reduced to the consistence of honey, which is smeared on the eyebrow and outside of the eyelids, or in that of a so- lution of the extract, (ext. belladonn. gr. xx, aq. destillat. f j, solve et per linteum cola,) which is dropped into the eye. They may be also applied in the form of a solution of their active principles, atropine or hyoscyamine, dropped into the eye, as originally recommended by Dr. Reisinger. (Atropiae sulphat. gr. ij—jv, aq. dest. §j; or hyoscyamiae gr. jv—viij, aq. dest. ^j.) 102. When the belladonna is applied in the form of soft ex- tract externally, the dilatation of the pupil takes place less quickly than when applied in the form of a solution dropped into the eye, the effect in this case being produced in a quarter of an hour or so. 103. Opaque appearance behind the pupil depending on opacity of the crystaline body.—When opacity of the crys- taline is considerable, its seat can scarcely be mistaken even when we look into the eye directly, but when less considerable, it may in general be pretty certainly determined by looking into the eye sideways, when it will be known to be in the crys- taline by the greater or less closeness of its situation behind * In a case of congenital absence of iris, which I had the opportunity of seeing through the kindness of Mr. E. Smith, Billitersquare, when the light fell upon the eyes in a certain direction, a dark red reflection from their bot- tom was observed. OPAQUE APPEARANCE BEHIND THE PUPIL, ETC. 39 the iris. The opacity of the crystaline may, however, be so slight as not to occasion any very striking change in the black appearance of the pupil. In such cases, the state of the crys- taline is ascertained by the catoptrical examination. 104. Catoptrical examination of the crystaline body.—The pupil being dilated by belladonna, and the patient sitting with his back to the window, if a lighted taper be held before the pupil, three images of it are seen situated one behind the other, if the cornea and crystaline are of their natural transparency. Of these images, the anterior and posterior are erect, the middle one inverted. The anterior is the brightest and most distinct, the posterior the least so. The middle one is the smallest, but it is bright. If the taper be moved, the two erect images follow its motions in the same direction, but the inverted image moves in the opposite direction, though not so quickly, nor through so great a range as the other two. The anterior erect image is produced by the cornea, the posterior by the anterior surface of the lens, and the middle or inverted image is produced by the concave surface of the posterior wall of the capsule. 105. The posterior erect and the inverted images are not produced, if the anterior part of the crystaline body be opaque, whether the rest be opaque or not, but if it is the centre or the posterior part only which is opaque, the posterior erect image is produced, but not the inverted one. When the opacity is as yet slight, the images may be produced, but will be more or less indistinct. Of course the anterior erect or corneal image is not affected, unless the cornea is diseased. 106. The state of the posterior segment of the eye cannot be so directly explored as the state of the anterior segment, but may be inferred more or less accurately from the presence or absence of opaque appearances behind the pupil depending on reflection of light from the bottom of the eye, and from the attending subjective phenomena, together with the objective phenomena presented by the anterior segment, and by the eye considered as a whole. 107. Opaque appearance behind the pupil depending on re- flection of light from the bottom of the eye.—An opaque ap- pearance behind the pupil is determined to be of this nature, and at the same time, therefore, distinguished from opacity of the crystaline by the following marks:—The opaque ap- pearance is evidently deep seated, but where it is seated exactly, it is not easy to determine, especially as it changes its place according to the direction, in which the light is ad- mitted to the eye, it being always seen most distinctly on 40 COLD APPLICATIONS TO THE EYES. the side opposite the light, indistinctly or not at all on the side next the light. It is most distinct in the ordinary state of the pupil, but when the pupil is dilated by belladonna, it ceases to be very evident. The three images observed in the catoptri- cal examination are distinct. 108. The opaque appearance in glaucoma.—The peculiar green opaque appearance in glaucoma partakes partly of the characters just described as belonging to opaque appearances depending on reflection from the bottom of the eye, and partly of the characters belonging to opacity of the crystaline. Thus, it appears deep and to change its seat according to the direction in which the light is admitted, and when the disease is advanced, the inverted image in the catoptrical examination is indistinct or obliterated. The cause and true seat of the appearance, in regard to which there is a difference of opinion, will be con- sidered under the head of glaucoma. 109. Consistence of the eyeball to the touch.—By pressing on the eyeball with the finger through the medium of the tarsal edge of one of the eyelids, the consistence of the eyeball should be ascertained; whether it be normal or of unusual hardness or softness. Hardness of the eyeball indicates dissolution of the vitreous body, and too great quantity of the fluid. Softness or flexibility of the cornea or sclerotica, indicates atrophy of the vitreous body. Section II.—APPLICATION OF REMEDIES TO THE EYES OR THEIR NEIGHBOURHOOD, AND PER- FORMANCE OF MINOR OPERATIONS ON THEM. a. Cold applications to the Eyes. 110. Cold lotions.—Cold spring water is the best cold lotion. It is applied by means of compresses of old linen or lint, which should be broad enough to extend over the neigh- bouring parts as well as over the eye, but not so heavy as to press unpleasantly. When once commenced, the application of the cold lotion requires to be assiduously kept up as long as is necessary, one compress, as soon as it becomes warm, being replaced by another just taken out of the water. 111. Cold douche bath.—This consists in a fine stream of cold spring water allowed to play on the closed eye and neigh- bouring parts. The application may be continued for about MEDICATED VAPOURS TO THE EYES. 41 a quarter of an hour at a time. There are particular douche apparatuses. A simple form of one may be readily constructed with a glass tube of the thickness of a barometer tube, and from three to three and a half feet long, bent like a syphon six inches from one end, whilst at the other it is drawn out small, and also bent, but only for about two inches; the short limb of the syphon being immersed in a vessel of water placed at a convenient height, the air is sucked out at the small end, when a fine stream of water will issue from it. 112. Dry cold.—In the weak and rheumy eyes of old per- sons, and in a similar state remaining after an attack of ophthal- mia, it is often agreeable, and indeed, productive of great relief, occasionally to draw some cold body across the eyelids. For this purpose a long slender bottle with a smooth round bottom, and filled with ice, has been recommended. b. Warm Applications to the Eyes. 113. Warm cataplasms and fomentations.—As applica- tions to the eye, fomentations are much more convenient and ele- gant than poultices. Warm water simply may be used for the purpose, or chamomile decoction, poppy decoction, and the like. The application is made by means of compresses, as just de- scribed for cold lotions. The application requires only to be made occasionally, and that merely for a period of from five minutes to a quarter of an hour at a time. Warm cataplasms and fomentations should never be allowed to become cold on the eyes. After their removal, the eyes are to be gently dried with a soft linen cloth, and care taken that they be not exposed to a draught of air. 114. Watery vapours.—In order to receive watery vapours on the eyes, the patient holds his face over a vessel containing hot water ; a cloth being thrown over all. When it is wished to have steam play more directly on the eye, a funnel is invert- ed over the vessel, and the tube directed towards the eye at a proper distance. After the application, the face and eyelids are to be well dried, and exposure to any draught of air carefully avoided. c. Medicated Vapours to the Eyes. 115. Medicated watery vapours.—In some cases, the hot water is mixed with some aromatic or narcotic substance, such as tincture of opium, tincture of camphor, compound tincture of camphor, tincture of hyoscyamus, a spirituous or vinous solu- tion of extract of belladonna, (5j —SjO in the proportion of a 42 STIMULATING VAPOURS. teaspoonful or two to the cupful of hot water about to be used for steaming. 116. Dry warmth and vapours of aromatic or narcotic substances.—Bags of aromatic or narcotic herbs hung over the eyes are employed partly to keep up dry warmth, and partly for the sake of the exhalations they give out. The bags are made of coarse lawn or muslin, washed and rubbed soft. Be- ing lightly filled, the bag is sewed close, and then quilted at dif- ferent places, so as to keep the materials equally spread out, and to prevent them from sinking down. The bags ought to be made as light as possible, not more than of the thickness of a finger, and about the size of a playing-card. They are fixed to a band passed round the forehead, so as to hang free: they ought not to be bound over the eye. The bags are warmed before being applied. The materials used for filling the bags are aro- matic species, (chamomile flowers, sage, rosemary, thyme, &c,.) mixed or not with shavings of camphor. The species are re- duced to a coarse powder, from which all dust is to be separated by a sieve. To fill a bag of the size above indicated, one and a half to three drachms of herbs, flowers, &c, will be required. Bran or bean-flour is used as an excipient and diluent of the aromatic or narcotic materials. When camphor is the only active substance employed, it may be applied by means of a compress, prepared by enclosing a layer of cotton wool, impreg- nated with it, between two layers of gauze. The impregna- tion is readily effected by soaking the wool in strong spirit of camphor, and then allowing it to dry quickly ; when dry, the wool is teased out. 117. Examples of materials for herb-bags. R—Flor. chamomill. ----sambuc. aa p. j. Farin. fabarum, pp. ij. M. F. Pulvis. H.—Pulv. hb. belladonna. £j. Farin. amygd. dulc. §j. M. F. Pulvis. 118. Stimulating vapours.—The vapour of the weaker vola- tile fluids is applied by spreading the fluid out on a warm sur- face and allowing it to evaporate near the eyes. Thus, having poured a few drops of the fluid into one hand, and spread it out on the palms of both, by rubbing them quickly together, the hands are to be held one before each eye more or less close COLLYRIA, ETC. 43 according to the strength of the material and degree of action desired. d. Collyria, fyc. 119-—The word Collyrium, as at present understood, means an eye-water, but formerly it was applied to any medicine for the eyes, whatever its form. Recurring partially to the original and wider acceptation, it is purposed under this head to treat not only of eye-waters, but also eye-salves and eye-powders. The skin of the eyelids, and the conjunctival surface, are the parts of the eye which, under ordinary circumstances, are most open to the contact of remedies ; the derivative lachrymal pas- sages, though also directly, are less easily accessible. Of the other parts of the eye the proper substance of the cornea, when laid bare by ulceration, and the iris when it is prolapsed in con- sequence of a wound or penetrating ulcer of the cornea, are those which may become the subject of the direct action of medicinal substances. The lachrymal gland and Meibomian follicles may be influenced by the action of collyria on their excretory orifices, in consequence of the sympathy depending on continuity of structure. The internal tunics, also, by virtue of their contiguity, may be sympathetically affected by applications to the con- junctiva; though in general, when these are irritating, rather injuriously than beneficially. 120. Eye-waters and drops are solutions of astringent, stimu- lant or narcotic substances, or of all combined. Their state of concentration regulates the mode of application, hence the divi- sion into eye-waters properly so called, and drops for the eyes. 121. Eye-waters properly so called,a.re the weaker solutions, and are used to bathe the eye occasionally in the course of the day. The fluid is to be put into a cup in sufficient quantity and made tepid. The patient, holding his head over the vessel, is to lave his eye with the water by means of apiece of sponge or soft linen rag; and after this has been done for a few minutes, some of the fluid maybe dropped fairly into the eye by an assist- ant squeezing the soaked rag over it, while the patient lies on his back, and endeavours to hold his eyelids apart. After this, the eye may be laved again for a minute or so, and then care- fully dried with a soft linen cloth. An eye-glass is not to be recommended. 122. A principal object in the process above described is to remove any discharge from the eye. In the blennorrhceal oph- thalmia, when the eyelids are enormously swollen and cannot be opened, it may be necessary to inject the eye-water between 44 COLLYRIA, ETC. the eyelids, after they have been cleansed as much as possible by means of the bathing simply. In using the syringe, however, care must be taken not to injure the patient's eye by pressure or the like, and on the other hand, the operator should guard his own eyes from receiving any spirt of matter. 123. In order to act on the inner surface of the lachrymal pas- sages, the simplest way of applying the eye-water is to drop it into the inner corner of the eye, and leave it there a short time till some is taken up by the puncta. It is sometimes also inject- ed directly through the puncta and canalicules by means of Anel's syringe. Injections are occasionally thrown into the lachrymal passages from the opening of the nasal duct into the nose ; but when an external opening into the lachrymal sac exists, whether it has been made by operation or the bursting of an abscess, we have the readiest access to the mucous surface of the lachrymal passages. 124. Examples of eye-waters. R—Belladonnas extract 3fs. Aquae purae ^ viij. Solve et per linteum cola. Sig. Sedative eye-water, to be used tepid. R—Aluminis gr. xvj. Aqua. ros. ^viij. Solve. Ft. aqua ophthalmica. R—Sulphat. zinci gr. xvj. Aquae ros. §viij. Acid, sulph. dilut. gr. xvj. F. Solutio pro aqua ophthalmica. R—Hydrarg. bichlorid. gr. j. Ammoniae hydroc'hlorat gr. vj. Aq. ros. ,^viij. Solve, &c. R—Lapidis divini* gr. xvj. Aquas destillat. gj. Solve et cola. Colatura. adde aqua, rosarum ^vij. Misce, &c. Sig. Eye-water. * R—iEruginis, Nitratis potassae, Aluminis aa partes xvj. Terantur simul et liquefiant in vase vitreo in balneo arenae. Liquefactis adde camphora. tritae partem j : Misce. Massa refrigerata servetur sub nomine Lapidis Divini. COLLYRIA, ETC. 45 N. B. To any of the four last solutions, a drachm of vinum opii may be added. The following may be mentioned as directions for use :—To a wineglassful, add as much hot water as will make the whole lukewarm. With the quantity thus prepared, the eyes are to be bathed as directed. 125. Drops. These may be applied by means of a quill or glass tube, but a large camel's hair pencil will be found the most convenient instrument. It is to be remembered, however, that to avoid accidents, each patient should have a separate pencil, which ought to be well washed every time it is used. The lower eyelid being slightly everted, its inner surface is to be touched with the loaded pencil, when the fluid will be imme- diately drawn off and diffused over the lower part of the con- junctiva. Pains must also be taken to allow the drop to make its way underneath the upper eyelid by drawing this from con- tact with the eyeball, and then moving it slightly up and down. It is frequently necessary to evert the upper eyelid, and to pencil its conjunctival surface directly. 126. Applied in the ordinary way, salves, eye-waters, and drops, scarcely ever come into contact with the conjunctiva of the upper eyelid and eyeball* in any degree of concentration, and too often what does get there acts rather as an irritant than otherwise. I consider it of great importance to insure the ac- cess of an application to the upper parts of the conjunctiva, because I have seen cases treated unsuccessfully, or rather irri- tated for a long time by applications, which, when properly introduced, did not fail of a speedy beneficial operation. 127. In order to apply drops to the eye of a child with the least possible trouble, the surgeon is to seat himself on a chair, with a towel, folded longways, laid across his knees. On another chair, on the surgeon's left hand, and a little in front of him, the nurse with the child sits in such a way, that when she lays the child across her lap, its head may be received on the towel, and between the knees of the surgeon, and thus held steadily. The nurse confining the hands and arms of the child, the surgeon easily draws down the lower eyelid and drops in the fluid; he then draws the upper eyelid up a little, and also from contact with the eyeball, in order to allow the drop to get underneath. The eyelids are then alternately to be drawn from each other, and made to approach so as to favour the spreading of the fluid over the whole conjunctival surface. * In illustration of this, it may be mentioned, that in most or all the cases in which, from the abuse of the nitrate of silver drops, the conjunctiva has become discoloured, it is the lower part of this membrane which is so affected. 46 EYE-SALVES. 128. Examples of eye drops. Vinum opii, pure, or diluted with one or two waters, is often used for dropping into the eye. R_Nitratis argenti gr. iv—x. Aquae destillatae gj. Solve. R—Hydrarg. bichlorid. gr. fs. Aquae destillatae ^vij. Solve et cola. Colatura. adde vini opii gj. Misce. R—Lapidis divini gr. v—x. Aquae destillatae 3vij. Solve et cola. Colaturae adde vini opii -jj. Misce. R—Extract, belladonnas gr. xx. Aquae destillatae §j. Solve et per linteum cola. R—Atropiee sulphat. gr. ij—iv. Aquee destillatae §j. F. Solutio. 129. Eye-salves.—Salves are applied to the borders of the eyelids, or to the whole conjunctival surface. In the former case only, should the patient or his attendants be intrusted with the application. In the latter case, more discrimination, as well as tact, being required, the surgeon should apply the salve himself. 130. Before applying a salve to the edges of the eyelids, all incrustations of matter about the roots of the eyelashes must be removed. This is done by first rubbing the part with fresh butter or lard, and after a while bathing it with tepid water; the incrusting matter is thus softened, and may readily be sepa- rated with the finger-nail or head of a pin. 131. The anointing of the edges of the eyelids may be per- formed by means of a hair pencil, or simply with the point of the finger. The eyelid being held slightly everted, the salve is applied along its border to the mouths of the Meibomian follicles, then smeared outside the insertion of the eyelashes, and afterwards carefully rubbed in at their roots, the eyelids being at the time kept gently closed. 132. When a salve is to be applied to the whole surface of the conjunctiva, a piece the size of a split pea is to be taken up on the point of a probe, or on the point of the nail of the little EYE-SALVES. 47 finger, and insinuated under the upper eyelid, while this is drawn forward from contact with the eyeball. When the salve is fairly in the eye, the upper eyelid is to be gently drawn down, and rubbed over the eyeball with the finger for a minute or two, in order to diffuse the salve, now melted by the heat of the eye, between the eyelids and eyeball, and consequently all over the conjunctiva. 133. If the palpebral conjunctiva be the part on which the salve is principally to exert its action, the application may be limited to it, in which case the pain is less severe than in the former. Having everted the eyelids, the exposed conjunctival surface is to be rubbed with the salve either by means of a hair-pencil or the point of the finger. 134. Salves are sometimes applied to the lachrymal passages, by smearing the meshes, catgut-strings, &c, which are intro- duced into the nasal duct, whether from the nose or through an external opening into the lachrymal sac. 135. In regard to the application of a strong salve to the eye, it is necessary here to give a caution, viz., not to insert it in a lump within the lower eyelid and leave it there. I have seen the conjunctiva of the inferior palpebral sinus in a sloughy state from a lump of nitrate of silver ointment having been put in, and no care taken to diffuse it by rubbing the eyelid over the eyeball. In the case of ointment inserted under the upper eyelid, the natural motions of the part will make up in some degree for the neglect of the surgeon. 136. Examples of eye-salves. R—Oxid. hydrarg. rrbri bene laevigat. gr. iii—vi—xv. Axungiae praeparat. ^ij. Misce accuratissime: ft. unguentum ophthalmicum. The two weaker forms are used for anointing the edges of the eyelids, and may be entrusted to the patient. The stronger form should be applied only by the surgeon himself. Applied to the whole conjuctival surface it is found a very efficient re- medy in various inflammations of the conjunctiva, and ulcers, specks, &c, of the cornea. It is less severe in its operation than the nitrate of silver ointment. The citrine ointment of the pharmacopoeias, diluted with three or more parts of lard and oil, is a useful application to the edges of the eyelids. R—Argent, nitrat. gr. ij—x. Aq. destillat. q. s. ad solvend. nitrat. Unguent, cetacei gj. Prius solvatur nitras; dein misceatur accuratissime solutio cum un- guento. 48 EYE-POWDERS. This ointment has been used with much success not only in chronic, but also in cutting short acute inflammations of the conjunctiva; but the pain it causes is very severe. The following is what is known by the name of Janin's ointment for the eyes. R—Praecipitat. alb. gr. xv. Tutiae praeparat. Boli armen. ppt. aa. gfs. Adip. suilli gi—gij. M. exactissime: ft. ungt. ophthalmicum. 137. -It is of great consequence that eye-salves should contain no gritty particles; the powders entering into their composition, therefore, should first be reduced by trituration to as impalpable a state as possible, and then carefully levigated with a little water or oil, previously to being mixed with the excipient. Substances soluble in a small quantity of fluid, such as the nitrate of silver and sulphates of zinc and copper, may be dissolved. When camphor enters as anin gredient into an eye-salve, it should first be dissolved in a fixed oil. The excipient best adapted for eye- salves is prepared lard, simple cerate, or spermaceti ointment. 138. Eye-powders or Dry Collyria.—The application of irritating powders to the eye is much less frequent now than formerly. They were principally used against specks of the cornea. Insufflations of calomel have been strongly recom- mended in the puro-mucous ophthalmia. The powder, reduced to the greatest impalpability, pulvis subtilissimus, is blown into the eye through a quill, or applied by means of a moist hair pencil. The surgeon should always do the operation himself. Refined sugar or sugar-candy reduced to a very subtle pow- der has been principally used either alone, or as an excipient and diluent of other substances. 139. Examples of eye-powders. R—Sacch. purif. Oxid. zinci aa pp. seq. Misce, et tere ut fiat pulvis subtilissimus. R—Oxyd. hydrarg. rubri gr. x. Sacch. purif. 3J. Misce, et tere, &c. R—Calomelanos Sacch. pui;if. aa pp. aeq. Misce, et tere, &c. To this one-third of a part of powdered opium may be added. APPLICATION OF LEECHES TO THE EYES. 49 R—Aluminis usti, Sulphat. zinci, Boracis aa 9j. Sacch. alb. 9ij. Misce, et tere ut fiat pulv. subtiliss. The proportions above given may be varied according to circum- stances. e. Potential cautery. 140. It is sometimes required to touch fungosities of the conjunctiva, ulcers of the cornea, prolapsed iris, partial sta- phyloma, &c, with caustic. The caustics usually employed, are the nitrate of silver, or caustic potass pencil, and the butter of antimony. The latter is applied by means of a hair pencil dipped in it, and freed from any excess. In performing the operation, an assistant secures one eyelid, the surgeon the other, and that in a way according to the part which is to be cauter- ized. The surgeon then proceeds to make the application of the caustic, carefully confining it to the particular spot. This being done, some sweet oil is to be pencilled on the part before the eyelids are allowed to close. Cauterization of the skin of the eyelids, by sulphuric acid, to remedy entropium, by producing contraction of the skin, will be described under the head of Entropium. f. Local abstraction of blood. 141. Cupping.—When blood is to be abstracted by cupping in diseases of the eyes, it is usually on the nape of the neck, or on the temples, that the operation is performed. 142. Application of leeches to the eyes.—The region corre- sponding to the margin of the orbit all round, the side of the root of the nose, and the temple, close to the outer angle, are the places where leeches are most advantageously applied in inflammation of the eyes. A leech, or two, are sometimes applied within the nostrils, and occasionally to the conjunctiva, though the latter is a place of application not much to be recom- mended__first, because the resulting wounds are elevated, and cause irritation like foreign bodies; and secondly, because scarification is preferable. 143. Half a dozen is the average number applied around one eye in a grown-up person.* In infants, when it is necessary to abstract blood, one leech to the middle of the upper eyelid is sufficient. In very young infants, it is -to be remembered, * [The author here speaks of the European leech; of the American fifty or sixty may be applied.] 4 50 SCARIFICATION OF CONJUNCTIVA. however, that the after-bleeding from even one leech may prove fatal, if allowed to continue. The abstraction of blood by scarification is, therefore, to be preferred, especially as the affection of the eyes in infants requiring abstraction of blood, is the ophthalmia neonatorum, in which a scratch or two on the conjunctiva of the everted lids produce a considerable and bene- ficial discharge of blood. 144. When the after-bleeding (which, it is to be remarked, usually takes place in any quantity from certain of the bites only, and generally more freely on a first than on subsequent application), has been kept up sufficiently long, by means of warm fomentations, these are to be laid aside, and the skin carefully dried, when the bleeding will in general cease of itself; if not, pressure is to be made on the bites with the point of the finger, for a short time, or the bites touched with much-diluted nitric acid (gtt.j— 3ij). 145. Discoloration of the eyelids from ecchymosis, generally results from the application of leeches, for which the patient should be prepared. From idiosyncrasy, erythema, or erysipe- las—with very considerable oedema perhaps—is sometimes the result of the application of leeches to the face. In ordering leeches, therefore, to the face, inquiry should be made if leeches were ever applied before, and if any such tendency to erythema manifested itself. Though alarming to the patient, the erythema and cedema in general soon subside. A saturnine lotion may be used as an application in such a case. Sometimes, especial- ly under the circumstances just mentioned, suppuration of the wounds takes place, and knotty cicatrices are left. [These cicatrices usually produce some degree of disfigure- ment, and in females, therefore, the practitioner should not apply leeches to the cheek, or close around the orbit. Indeed, we consider it preferable not to apply leeches to those regions in any case, as they are there often productive of irritation, and we always direct their application to the temples or behind the ears.] 146. Scarification of the conjunctiva.—The simplest instru- ment for this purpose is a common lancet, rounded at the point. 147. Scarification of the conjunctiva of the lower eyelid.— In order to this, the lower eyelid is to be everted, by apply- ing the points of the fore and middle fingers of the left hand on the middle of the eyelid, and in such a way that the extreme points correspond to the insertion of the eyelashes. The skin of the eyelid and neighbouring part of the cheek is now to be drawn down a little; and when this is effected, the extreme SCARIFICATION OF CONJUNCTIVA. 51 points of the fingers are to be directed backwards, gently push- ing them a little between the lower margin of the orbit and the eyeball. By this means the conjunctiva is fully exposed, stretch- ed, and rendered prominent. Two or three scratches are then to be made with the instrument, held perpendicularly to the surface, in a direction from one angle of the eye to the other. The blood flows more or less freely in drops, and is to be taken up with a pit of dry lint held to the edge of the eyelid, but not allowed to touch the scarified part, as this is apt to cause the blood to stop. When, however, the blood begins to coagulate on the scratches, and its further flow is stopped, the flakes of coagulated blood may be removed with a bit of wet lint. The flow of blood is promoted by every now and then allowing the eyelid to become less everted, and then again fully renewing the eversion. 148. Scarification of the conjunctiva of the upper eyelid.— The upper eyelid is not so easily everted as the lower; but in those cases in which scarification is most required, the eversion is generally more easily effected, on account of the swollen state of the conjunctiva. The upper eyelid being everted, as already described (s. 36), it is to be kept so by means of the eyelashes pressed against the upper margin of the orbit, whilst the scarifications are made, and as long as the blood flows. When the conjunctiva is much congested. and sarcomatous, as in ophthalmia neonatorum, more scarifications are to be made than in the lower eyelid. In some cases of chronic inflamma- tion, the conjunctiva of the upper eyelid is red and spongy looking, towards the angles, but not much affected in the mid- dle. In these cases, the scarification is to be confined to a slight scratch or two on the red and spongy places. 149. In granulated conjunctiva, a mode of scarification, which I have employed with advantage, consists in making a small crucial incision through each granulation, or when they are small and closely compacted, by making a number of cross h3.tcll6S. 150. It has been objected to scarification, that the traumatic irritation which is occasioned does more harm than all the good effected by the loss of blood. But this is certainly not a cor- rect view of the matter. In the proper cases, great and decided advantage is often obtained from scarification—not, however, so much by the mere quantity of blood abstracted, as by relieving the congestion of the conjunctiva, and thus preparing it to be more beneficially acted on by the applications made to it imme- diately after. 52 COUNTER-IRRITATION. 151. Division of enlarged vessels in the sclerotic conjunc- tiva.—This may be readily effected by means of a small sickle- shaped needle introduced through the conjunctiva under the vessel, and made to cut itself out, by which manoeuvre the ves- sel is divided. But it is usually found better to excise a portion of the vessel in order to obviate the reunion of the divided ends, and the refilling of the vessel, which readily take place. To effect this, the eyelids require to be held apart by an assistant, as both hands of the surgeon are necessarily engaged, the one in taking up with a hooked forceps a fold of the conjunctiva, containing the portion of vessel to be excised,—the other in snipping it and a piece of the vessel away with a pair of curved scissors. The scissors should be held with the convexity to- wards the eye, and ready for use, before the fold is taken hold of with the forceps. Generally, though the fold of conjunctiva is snipped away, the vessel is not cut, but merely exposed; in this case the exposed part of the vessel is to be seized directly with the forceps and cut away. 152. Excision and incision of chemosed conjunctiva.—In chemosis, the elevated fold of conjunctiva all round the cornea is excised or incised, partly for the sake of the bleeding there- by occasioned, and partly to relieve the tension of the conjunc- tiva, and the pressure it exerts on the cornea. Three plans have been had recourse to:— 1. The excision, by means of a hooked forceps and curved scissors, of small folds of the chemosed conjunctiva, here and there; or, the excision of the whole of the chemosed conjunc- tiva all round the cornea. 2. Simple incisions into the chemosed conjunctiva, concentric with the cornea or in no particular direction. 3. The plan recommended by the late Mr. Tyrrell, of making incisions in the conjunctiva, in a direction radiating from the cornea, and at the places corresponding to the intervals between the insertion of the recti muscles. For this purpose, the eye- lids being held apart, the one by the surgeon, the other by his assistant, the incisions are made by means of a cataract knife, which, with its back to the cornea and point towards the circum- ference of the eye, is to be made to transfix the overlapping fold of conjunctiva, and then pushed on till it cuts itself out. g. Counter-irritation. 153. In diseases of the eye, counter-irritation is usually made on the nape of the neck, behind the ears, or on the crown of the head, [or on the arm,] by means of repeated blisters, tartar-emetic FOREIGN BODIES IN OCULO-PALPEBRAL SPACE. 53 plaster, or rubefacient liniments. When the counter-irritation is required to be long-continued, it is made by means of warm plasters between the shoulders, a seton in the nape of the neck, or issue in the arm. 154. Counter-irritation may sometimes be applied nearer the affected organ, as on the temple, or the forehead, above the eye- brow, by means of small blisters, or the momentary application of a salve containing strong liquor ammonia,, in the proportion of 3ij or 3iv to Ij of lard. Counter-irritation has been recom- mended, in some cases, to the outside of the eyelids by means of cauterization with nitrate of silver, and even by the applica- tion of blisters. h. Evulsion of eyelashes. 155. The instrument best adapted for the per- formance of this simple but nice operation, is a forceps with broad points, like tweezers, fig. 5; but a common good anatomical forceps will do. The eyelid being slightly everted and drawn from the eyeball with his left hand, (s. 30, 31,) the surgeon, with the forceps in his right hand, proceeds to pluck out one hair after the other singly; and the mode of doing so is to take hold of it with the forceps as near its root as possible, and to pull it out steadily —not too quickly nor with a jerk, as by doing so the eyelash is more apt to be broken short. If the eyelash should break short, its stump must be care- fully looked for, seized with the forceps and plucked out^ for if left, it would irritate more even than the eyelash did when whole. If eyelashes are to be plucked out from both eyelids, the operation should be commenced on the lower. i. Foreign bodies in the oculo-palpebral space of the conjunctiva, and their removal. 156. When a foreign body has got into the oculo-palpebral space of the conjunctiva, it is in common language said to have got into the eye. 157. Chemical or mechanical irritation of the conjunctiva is followed by a spasmodic closure of the eyelids and the discharge of a flood of tears. If the irritation have been produced by a substance in a state of vapour, the conjunctiva is in this way protected from its further action, and the smarting soon subsides. Strong acid vapours, however,—of hydrochloric acid for exam- 54 FOREIGN BODIES IN OCULO-PALPEBRAL SPACE. pie,—may at once produce serious injury by decomposing the epithelium of the conjunctiva and cornea. 158. Consistent substances of a kind not calculated to adhere to the conjunctiva, are either immediately washed out of the eye by the tears, the discharge of which they have excited, or in the case of small particles, they may be found after some time lying enveloped in mucus in the lacus lachrymalis, having been carried there by the movements of the eyelids, and proba- bly also by the action of the vibratile cilia of the palpebral conjunctiva. 159. When a foreign solid particle lies between the firm part of the eyelid and the eyeball, it causes great irritation, and ex- cites the orbicularis muscle to strong spasmodic action. This serves but to aggravate the distress, by fixing the particle, if it be of a nature to adhere to the conjunctiva. 160. In a case in which a foreign body has got into the eye, and from the seat and severity of the irritation it is supposed to be lodged between the firm part of the upper eyelid and the eyeball,—if on gently raising the upper eyelid, and carefully examining the surface of the cornea and white of the eye, the foreign particle be not detected there, and if after taking hold of the upper eyelid by the eyelashes, and drawing it down over the edge of the lower eyelid, so that the ciliary edge of the latter may sweep the inner surface of the upper eyelid, the particle is not felt to be removed, the upper eyelid should be everted, and its conjunctival surface examined as above described (ss. 36, 38), when most probably the offending particle will be discovered adhering to it. If the foreign particle is not at once detected, the possibility of its being transparent should be taken into consideration, and an examination of the whole exposed surface made with great care. 161. The foreign particle having been detected, it may readily be removed by the touch of a hair pencil, moistened and brought to a point, or of a toothpick, or the eyed end of a probe, or any other flat blunt-pointed instrument. 162. Foreign bodies when within the lower eyelid do not cause so much irritation as when within the upper, and their detection is more easy, the lower eyelid being more readily everted than the upper, (s. 34.) 163. Foreign bodies which have entered the oculo-palpebral space, sometimes get lodged in the palpebral sinuses of the con- junctiva, and may there be retained for a length of time, with- out causing much or any irritation, the conjunctiva of the sinuses being so loose, and the subjacent cellular and adipose tissue of FOREIGN BODIES IN OCULO-PALPEBRAL SPACE. 55 the orbit so soft, that the body is not much pressed on by the opposing surfaces. The large size of the bodies which have been found lodged in the palpebral sinuses without having given rise to irritation, is astonishing. 164. When, therefore, notwithstanding the absence of much, or any irritation, there is still reason to believe that a foreign body is in the oculo-palpebral space, and when, by the mode of examination above described, it has not been detected, atten- tion should be directed to the palpebral sinuses, and an explo- ration of them made as above described, (ss. 34, 37.) 165. A foreign body, especially when projected with force into the eye, may at once adhere to the ocular conjunctiva— generally the conjunctiva cornea.. It sometimes happens that the husks of small seeds, and other analogous bodies, such as the wing-case of certain insects, or, as I have seen in a fisher- man, one of the valves of a minute bivalve shell, getting into the eye, adhere very closely to the sclerotic or corneal conjunc- tiva. Inflammation having set in, these foreign particles are liable to be mistaken for pustules or phlyctenule, resulting from the inflammation. This, therefore, should lead to a careful examination in any suspected case, when the nature of the body on the cornea cannot fail to be recognized. Removal is readily effected by any of the instruments above mentioned. 166. The ignited sparks detached from iron instruments in the course of various operations, called fires, and which so frequently strike and sink into the conjunctiva cornea of the workman, appear as small dark points on the surface, with some dimness of the cornea around. They give rise to more or less pain, especially when the eyelids are closed, together with redness and lachrymation. 167 The foreign body is at first firmly fixed, but afterwards becomes loose, ft is in general easily turned out of its nidus by means of a toothpick or small silver spatula.* When re- moved it is found, on close examination, to be black oxide of iron fused into a minute globule. 168 If the removal from the eye, of such foreign bodies as are above mentioned, is effected soon, the distress is in general at once relieved or greatly mitigated. Sometimes a sensation remains as if the foreign body were still in the eye; this is owing either to vascular injection or to abrasion of some part of the conjunctiva. 169 Caustic, or hot substajnces, whether solid or fluid, getting into the eye, so quickly exert their action, that much, if not all, * [We usually employ for this purpose a cataract needle.] 56 EVACUATION OF AQUEOUS HUMOUR. the injurious effects have already occurred before means can be taken for their removal. 170. While solid caustic substances are still in the eye, the best application to make in the first instance is sweet oil. After that, the surgeon may proceed to remove the foreign substance, and to effect this some pains will often be required, especially if it has been lime or mortar, for the particles of these substances are apt to adhere very closely to the conjunctiva. Exploration of the palpebral sinuses should not be neglected lest pieces may have lodged there. After the eye has been freed as completely as can be done from particles of lime or mortar, water should be injected into the eye in order to carry away what remains of the caustic may exist. 171. When gunpowder has been exploded into the eye, be- sides the burn which results, the grains may fix in the conjunctiva and in the cornea—in which case, unless carefully picked out, they will leave indelible marks and opacities. 172. Particles of such substances as potass, nitrate of silver, <__e., getting into the eye, quickly become dissolved in the tears, and their injurious operation may spread like that of a caustic fluid, before they can be removed. 173. In this case, and in the case of caustic fluids, the ap- plication, in the first instance, should be some substance calcu- lated to decompose them and render them inert, so as at least to arrest their further destructive action; thus, in the case of sulphuric acid, which has sometimes been thrown into the eyes of persons with a criminal intention, a solution of subcarbonate of soda—gr. iv aq. ,§j, or magnesia suspended in water, should be immediately used as a lotion and injection for the eyes. 174. Simply hot substances, such as melted tallow, pitch or lead, quickly cool of themselves, and all that requires to be done in the first instance is their removal. If pitch cannot be readily removed, sweet oil will promote its separation. 175. The effects of the intrusion of different foreign bodies into the eye, and their treatment, will be considered under the head of Injuries of the Eye. k. Paracentesis of the cornea, or evacuation of the aqueous humour. 176. The various objects for which this operation is had recourse to, are detailed in their proper places. Here the operation itself only falls to be described. It is simply the first step in making the section of the cornea for the extraction of a cataract. A cataract-knife or a lancet-shaped knife is the OPHTHALMIC INFLAMMATION. 57 instrument best adapted for the purpose. If the operation is undertaken when the eye is very intolerant of light, there is great difficulty in exposing the cornea sufficiently for the pur- pose, as on the eyelids being opened, the eyeball is involun- tarily rolled upwards. One eyelid requires to be secured by an assistant, while the surgeon takes charge of the other. The knife is entered at about one-twentieth of an inch from the scle- rotica, and, in doing so, the principal precaution to be observed is not to push the point on in the substance of the cornea, under the impression that it has penetrated into the anterior chamber. The thickness of the cornea and the direction of its surfaces, are such, as to require the point of the instrument to be at first directed towards the centre of the pupil. The point of the instrument having fairly pierced the cornea, its handle is to be inclined towards the temple before pushing the blade farther into the anterior chamber. The extent to which the blade is pushed into the anterior chamber should be such, that its point do not advance beyond the temporal margin of the pupil, so that were the aqueous humour suddenly evacuated, the iris might be between the point of the instrument and the lens. Hence the propriety of using an instrument of the shape mentioned, which is calculated to make a sufficiently large puncture with- out penetrating far into the anterior chamber. The puncture having been sufficiently made, the instrument is to be withdrawn a little and slightly turned on its axis, so as to make the wound gape, and thus allow the aqueous humour to flow out. In proportion as this takes place, and the iris approaches the cornea, the knife is withdrawn. CHAPTER II. OPHTHALMIC INFLAMMATION. 177. As many of the most important of the diseases of the eye consist either in inflammation itself, or in its effects, and as all our operations on the organ must be regulated by the kind and degree of inflammation we expect to follow, an accurate knowledge of the ophthalmia, must ever be considered the master-key of our subject. Ophthalmic inflammation, therefore, is worthy of the most particular attention of the prac- 58 INFLAMMATION IN GENERAL. titioner. Preparatory to entering on its study, it will be useful to give a brief exposition of the nature of inflammation in general. Section I.—INFLAMMATION IN GENERAL. 178. When a part of the body visible externally is affected with inflammation, the observer perceives it to be the seat of redness, swelling, and heat; the patient moreover says that he feels it to be the seat of heat and pain. The conditions on which these symptoms depend are briefly these:— a. The redness is owing to the stagnation and accumulation of red blood-corpuscles in the small vessels—in other words, to congestion. b. The swelling depends partly on the distension of the small vessels by the accumulated blood, but principally on the infiltration of the part with exuded matters. c. Heat.—The objective increase of heat, or that actual increase ascertainable by the thermometer, may be, in a general way, correctly enough attributed to the increased accumulation of blood, and other attendant conditions, favouring a more active operation of those causes on which the natural production of heat depends. The patient's sensation of increased heat depends partly on the actual increase of heat as ascertained by the ther- mometer, and partly on an increased susceptibility of the sensi- tive nerves. d. Pain.—The pain which may occur at first is owing to the change of state of the sensitive nerves, occasioned by the excit- ing cause of the inflammation. The increase of pain, the new kinds of pain, and the extension of pain to other parts which subsequently occur, are owing, in addition to the irritation pro- duced by the pressure exerted, by the distended vessels and by the exuded matter, on the common sensitive nerves already in a state of excitement, to sympathy, &c. When there is much throbbing, the attending pain is aggravated at each pulsation in consequence of the increase of pressure occasioned at the time. The nature of the process which leads to these conditions —in other words, the theory of inflammation, now claims consideration. FIRST STEPS OF INFLAMMATORY PROCESS. 59 A. INFLAMMATION PROPER. a. Phenomena attending the first steps of the inflammatory process. 179. Retardation of the flow of blood in the small vessels, coincident with dilatation of their calibre, and accumulation, and at last stagnation of the blood corpuscles in the vessels, consti- tute the first phenomena, constantly appreciable by the micro- scope in the inflammatory process, as observed in the frog. The macroscopical phenomena of inflammation in man, being similar to those observed in the frog, seem to warrant the inference, that the microscopical ones also are essentially the same in him as in the frog. The explanation of these phenomena, therefore,—their sequence and relations,—is justly considered the key of the whole theory of inflammation. 180. That the dilatation of the small vessels is primary, and the retardation of the flow of blood in them secondary,—the ne- cessary physical result of the preceding dilatation—is the opinion maintained by most recent authors. And the opinion is to be considered just but only so far as it goes, for it does not embrace the whole truth. The truth appears to be this:—The dilatation is primary, but the retardation of the flow of blood is only partially the effect of it, being greater than the dilatation is sufficient physically to account for. The other cause in opera- tion is what at last determines the accumulation and stagnation of the blood, as will be explained below. By the accumulation of the blood, however, there is a secondary dilatation of the vessels—one from distension, but which more particularly im- plicates the capillaries—perhaps the sole dilatation of which the capillaries proper are the seat, as will immediately be shown. 181. Having thus determined that there is primary dilatation of the vessels, the next subject of inquiry is the nature of the dilatation. Does it depend on an active state of the walls of the vessels, or on a state of relaxation ? The prejudice that inflammation is a state of increased action of all the parts con- cerned, which has led some (justly believing that constriction is the active state of the vessels) to maintain that the vessels are constricted in inflammation, has led others (knowing that the vessels are really dilated in inflammation) to maintain that their dilatation is an active state. These opinions, however, are equally inconsistent with established physiological princi- ples, as they are opposed to the results of direct observation. 182. The fact is that, as was originally suggested by Vacca, 60 CAUSE OF THE STAGNATION OF THE BLOOD. and in corroboration of which microscopical observations were first adduced by Wilson Philip, and now admitted by most authors on the subject, the dilatation of the arteries in inflam- mation is a state of relaxation or paralysis, not of activity. The increased force of the pulsation of the arteries leading to an inflamed part, and on which throbbing depends, it is to be par- ticularly remarked, is not owing to increased contractile power of the walls of the arteries, but, on the contrary, to diminished contractile power. Being thus relaxed, they yield more readily to the impulse of the blood propelled into them at each stroke of the heart. 183. Whether the capillaries and venous radicles have con- tractile coats, and therefore subject to dilatation from relaxation is a point which has not been so satisfactorily determined.— I am disposed to believe that dilatation of the capillaries and radicles of the veins is secondary to the retardation of the flow of blood in the arteries, and is owing to distension from the accumulated blood. The constriction of calibre which the capillaries are said to present, though to a small amount, may be ascribed to elastic reaction of their walls, as it exists at the time when the arteries are constricted, and when the flow of blood is accelerated and not impeded by any tendency of the red corpuscles to accumulate. b. Cause of the accumulation and stagnation of the blood corpuscles in the relaxed and dilated vessels. 184. Retardation of the flow of blood has no effect in pro- ducing accumulation and stagnation of the red corpuscles, and though in consequence of it accumulation and stagnation of colourless corpuscles may take place, this is never to such an extent as to arrest the flow of the red corpuscles. 185. The appearances attending the stagnation of the red corpuscles, viz., the red corpuscles agglomerating together, and applying themselves here and there flat against the walls of the vessels and adhering to them, whilst other red corpuscles apply themselves to those already adherent, are such as might be supposed to be the effect of a suspension of the conditions by which, in the natural state, the red corpuscles keep in the mid- dle of the stream, neither adhering to the walls of the vessels nor to each other, and do not readily enter the smallest capillaries —the effect, in fact, of the establishment of an attraction between the red corpuscles on the one hand, and the walls of the vessels on the other, as well as among the red corpuscles themselves, instead of the absence of attraction or the actual repulsion which CAUSE OF THE STAGNATION OF THE BLOOD. 61 naturally exists. But supposing all this—supposing that attrac- tion does come into operation, the question remains, How is the attraction called forth? or what are the conditions on which it immediately depends ? or even which attend it ? 186. Before entering upon an exposition of the theory which appears to me to harmonize most completely with all the facts of the case, I assume the following propositions:— 1. That the constriction and dilatation of the calibre of the small arteries at least, if not of the capillaries, are owing to contraction and relaxation of their walls by virtue of the vital endowment of contractility or tonicity which they possess ; the exercise of which contractility is dependent on nervous influ- ence. 2. That the constant moderate exercise of this endowment on which the ordinary state of tone of the vessels depends, is determined by the constant moderate discharge of nervous in- fluence. 3. That whilst a greater state of constriction of the vessels than ordinary is owing to an increased discharge of nervous influence, the relaxation, atony, or paralysis of the walls of the vessels on which their dilatation depends, is owing to the suspension of nervous influence. 4. That the relaxation, with dilatation of the vessels from suspension of nervous influence, is the precursor of the retarded flow of blood and stagnation. 187. How the suspension of nervous influence from the walls of the small arteries on which their dilatation depends, is produced, involves the question of the mode of operation of the exciting cause of inflammation. To this attention will by and by be directed. At present inquiry has to be made how the suspension of nervous influence from the small arteries, and the consequent relaxation and dilatation of these vessels are connected with the retardation of the flow of blood and subsequent stagnation. 188. In entering upon this inquiry, I have in the first place to remark, that it appears evident that the well-known agglo- meration of the red corpuscles of newly-abstracted blood, is owing to their being withdrawn from some influence under which they were while in the body—an influence which keeps down the tendency to aggregate. 189. The circumstance that the red corpuscles of extrava- sated blood aggregate, shows that that influence is exerted on the blood only while within the vessels. But the circum- stance, that the red corpuscles do aggregate in inflammation 62 ACTION OF EXCITING CAUSE OF INFLAMMATION. within the vessels, shows that the influence here spoken of may cease to be exerted on the blood even there. 190. Now it has been seen, that it is not when the vessels are constricted, and consequently when they are receiving nerv- ous influence, but when they are dilated, and when, conse- quently, there is a suspension of nervous influence from them, that aggregation of the red corpuscles and consequent stagnation of blood take place in the capillaries. The natural inference from this is, that the influence which keeps down the tendency of the red corpuscles to aggregate, is communicated to them by the nerves accompanying the small vessels—arteries, as well as capillaries. 191. When, then, the nervous influence is withdrawn from the small arteries, and they have in consequence become re- laxed and dilated, and when any nervous influence which may naturally be discharged on the capillaries is from the same cause withdrawn, the blood flows slowly into the capillaries as into an indifferent cavity, and in the same condition, as regards tendency of the red corpuscles to aggregate, as blood newly drawn from the body, or extravasated, as well as with the same change in appearance. 192. Aggregation of the red corpuscles accordingly takes place, some at the same time adhering to the walls of the ves- sels. The latter, a phenomenon which is to be attributed in like manner to the suspension of nervous influence. 193. The other cause, besides dilatation of the paralyzed vessels, referred to s. 180, of the retardation of the flow of blood, now appears, from what has been above said, to be the commencing agglomeration of the red corpuscles, and attraction between them and the walls of the vessels. By the dilatation of the vessels, retardation of the flow of blood as a whole—as a fluid is determined; the additional retardation by the commenc- ing attraction affects the corpuscles only, hence their accumula- tion in increased quantity while the plasma passes on. c. Mode of action of the exciting cause of inflammation. 194. Seeing that the essential condition of stagnation of the blood in inflammation, is suspension of supply of nervous in- fluence to the small vessels, the action of the exciting cause of inflammation must consist in producing this suspension. 195. In explanation of the mode in which this takes place, Professor Henle has suggested the following theory:— The exciting cause, of what nature soever it may be, whether external or internal, acts primarily on sensitive nerves, exalting their activity. The motor nerves of the vessels which have ACTION OF EXCITING CAUSE OF INFLAMMATION. 63 sympathetical relations with the excited sensitive nerves, are secondarily affected. But this affection of the motor nerves of the vessels, which supervenes by reflex action on the excite- ment of the sensitive nerve, is not a corresponding state of excitement, but an opposite one of depression—of suspension of action—of paralysis. 196. This form of sympathy, in which the state of excite- ment of one nerve determines depression of another, Henle calls antagonism ; the name of sympathy, in a restricted sense, being applied to that form in which a state of activity of one nerve is called forth by a corresponding state of another.— This latter form is more common in the domain of the cerebro- spinal system ; the former in the domain of the ganglionic sys- tem, the source of the nerves of the vessels. 197. Sometimes, however, sympathy is exemplified in the vessels by constriction supervening on irritation and preceding dilatation. But, in most cases, relaxation and dilatation of the vessels are not preceded by constriction, but directly supervene on the irritation, no matter whether that irritation have been violent or moderate. Hence Henle contends, that the relaxation of the vessels on which their dilatation depends, cannot be a mere consequence of exhaustion of the vessels from previous action, as has been suggested, but can only be antagonistic. Into this, however, it is not necessary to enter; for, provided suspension of nervous influence and consequent dilatation of the vessels do take place, it is indifferent for the theory of the proximate cause of inflammation above expounded, whether that state of the vessels be the result of antagonism or of ex- haustion succeeding a state of activity induced by sympathy. 198. Inflammation excited by exposure to cold, often affects some part other than that to which the cold was immediately applied. In such a case it may be said—hie stimulus, ibi fluxus; but in most cases of external inflammation which come under notice, the congestion occurs at the place where the irri- tation was applied-—ubi stimulus, ibi fluxus. Hence the widely-spread belief, that the irritation affects the vessels directly; but to say nothing of physiological examples of reflex action on remote vessels which may be adduced in contradiction of the belief referred to, such, for example, as the circumstance that irritation of the conjunctiva, or of the mucous membrane of the nose, excites the congestion in the lachrymal gland, on which the discharge of tears, resulting from the irritation, immediately depends; a pathological one—in various ways more instructive —will be adduced below in the inflammatory congestion of the 64 EXUDATION. conjunctiva and sclerotica which supervenes on a wound of the cornea. 199. Explanation of the occurrence of inflammation of a part after section or disease of its nerves.—In those cases in which inflammation of an organ occurs after section of some part of the sympathetic system—inflammation of the eye, for example, after section of the sympathetic in the neck,—as also in those cases in which inflammation of the eye supervenes on section of the fifth pair, and inflammation of the lungs and stomach on section of the par vagum, the inflammation was at one time attributed to the suspension of some peculiar in- fluence supposed to be exerted by the nerves over the nutritive process. It is now, however, admitted, that the nerves do not exert any peculiar influence over nutrition, but that they act indirectly only, and that by virtue simply of their ordinary sen- siferous and motiferous endowments. Even the sympathetic, as first declared by Stilling, acts in no other way. Why it ap- pears to be more particularly the nerve governing nutrition, is explained by the circumstance, that it is the principal source of the nerves of vessels. 200. Section of some part of the sympathetic nerve appears to produce inflammation, by directly suspending the nervous influence from the walls of the vessels of the part. 201. The inflammation which takes place after section of such nerves as the fifth pair, the par vagum, &c, appears to belong, as is suggested by Henle, to the same category as that which occurs after section of branches of the sympathetic; it being assumed, that sympathetic filaments or nerves of vessels are mixed with the fifth pair, par vagum, &c,—a postulate— in favour of which there are not only anatomical facts, but also physiological analogies. d. Exudation. 203. On stagnation of the blood, exudation speedily super- venes. At first serous, the exuded fluid comes at last to be pure plasma, or at least a fluid containing a greater or less quan- tity of fibrine. 204. None of the&orpuscles of the blood pass out along with the exuded fluid as long as the vessels are entire. But it is often observed, that at certain points the walls of the vessels in which the blood was stagnated have given way -and permitted an extravasation of both red and colourless corpuscles. 205. With exudation is completed the inflammatory process properly so called. INFLAMMATION OF NON-VASCULAR PARTS. 65 e. Inflammation of non-vascular parts. 206. In certain non-vascular parts, morbid actions may go on in all respects similar to those which usually attend or result from inflammation. The cornea, for example, though it is vascular whilst being developed, is, in its fully-developed and healthy state, non-vascular, and yet inflammation of the cornea is spoken of. 207. The cornea, there is reason to believe, derives the mate- rials necessary for its nutrition from the blood circulating in the vessels of the adjoining parts of the conjunctiva and sclerotica. Let us inquire what takes place in the cornea when there is applied to it such an irritation as would excite inflammation in one of the vascular parts of the eye. 208. When the cornea is injured, then, congestion of the ves- sels of the adjoining parts of the conjunctiva and sclerotica takes place, and exudation into the substance of the cornea by and by ensues. Thus, though non-vascular, and, of course, not the seat of inflammatory congestion, it becomes the seat of a very important part of the inflammatory process—the most important part, perhaps, as regards the events of the process. 209. The cornea in this state may therefore be said to be, to all intents and purposes, inflamed—the only difference in respect to it, as compared with vascular parts, being, that the vascular congestion is not in it, but in adjoining structures. 210. On the other hand it is to be remarked, that although these adjoining structures are the seat of the congestion, little or no exudation may take place in them or on them, and they .may therefore be said to be scarcely or not at all the seat of inflam- mation as regards the events of the process. When the con- junctiva and sclerotica are really inflamed, exudation in or on them may occur, but then the congestion is different in seat and extent from what it is when the cornea is the seat of the inflam- mation, and there may be no exudation into the cornea—the cornea may remain unaffected. 211. In the progress of inflammation of the cornea, this struc- ture may become vascular, but such an event is owing to the development of new vessels, such as also happens in inflamma- tion of vascular parts, and as will be considered below. 212. Though inflammation of the cornea, considered as a non-vascular part, has been thus dwelt on, the truth is, that all tissues, as regards their component elements, are, properly speaking, non-vascular, and differ from the cornea only in the degree of proximity to the vessels, and therefore in inflamma- 5 66 CHANGES IN THE BLOOD IN INFLAMMATION. tion only in the degree of proximity to the source of the exuda- tion. 213. But this very difference affords a natural analysis of the inflammatory process. It enables us to observe separately the two great stages of inflammation proper,—the congestion and exudation,—the congestion in one place, the exudation in an- other. It also enables us to observe, as will be shown below, in an uncomplicated manner, the eventual stages of inflammation, such as reorganization and suppuration. Lastly and especially, it enables us to analyze the mode in which the inflammatory irritation is communicated to the vessels—the mode of action of the exciting cause. 214. In what is ordinarily called a vascular part, the irrita- tion, for aught that could be said to the contrary, except by a round-about process of reasoning, as above seen, might act directly on the vessels, as some maintain; but in the case of irritation, applied to the cornea alone, and not either to the con- junctiva or sclerotica, it cannot do so. And for the very simple reason, that there are no vessels in it to be acted on. The vessels which are affected are those of the conjunctiva and sclerotica. 215. The mode in which these vessels are affected, in conse- quence of irritation applied to the cornea alone, appears to be this:—Excitement of the sensitive nerves of the cornea (for the cornea has nerves, though no vessels) calls forth antagonistically, according to Henle's principle, a state of depression, a tempo- rary paralysis of the motor nerves of the contractile fibres of the walls of the small arteries opening into the capillary network of the conjunctiva and sclerotica adjoining the cornea. The consequence of this is, first, relaxation and dilatation of those arteries, and then accumulation and stagnation of blood in the capillaries, in the manner already explained. f Changes in the blood in inflammation. 216. Change in the stagnant blood.—The red corpuscles, stagnant within the vessels, cease to be distinguishable individu- ally, and appear as if fused together into a uniform red mass. This change in the appearance of the blood supervenes on stagnation more or less quickly—a circumstance which seems to show that it is owing to some condition coming into opera- tion subsequently to the stagnation. 217. The apparent fusion of the red corpuscles, stagnant within the vessels, being like what is observed in buffy blood out of the body, and the same as may be artificially produced CHANGES IN THE BLOOD IN INFLAMMATION. 67 by an increase of viscid matter and diminution of salts in the plasma, it appears to me very probable that the change is owing to the action of the plasma, inspissated as regards its proteine constituents, but deprived of a portion of its water and salts by exudation of serum. 218. To transudation of colouring matter from the blood in the vessels into the adjacent parenchyma, as also to the endos- motic changes in the red corpuscles connected with their apparent fusion, the variations in the tint of the redness of an inflamed part appear to be owing. 219. Changes in the general mass of blood.—Inflammation may arise without any previous change in the general mass of blood, and if limited in extent, may run its course without the supervention of any such change. As, however, in inflamma- tion of any severity and extent, changes in the general mass of blood early show themselves, and as these changes, when they occur, exert an important influence by reaction on the inflam- mation and its events, they here require some consideration. 220. The most characteristic and important change which the general mass of blood in inflammation presents, is an in- crease in the quantity of fibrine, and a decrease in that of the red corpuscles. In connection with this change in respect of composition, there is a remarkable increase in the tendency of the red corpuscles to aggregate into rolls, when the blood is drawn from the body. 221. In consequence of the decrease in the quantity ot red corpuscles, blood drawn in a well-marked case of inflammation appears paler, thinner, and more fluid than natural. So much more fluid is it, that if a prick be made in the finger of the patient, the blood, instead of oozing slowly out in the form of a drop, flows out quickly, and spreads on the surface of the 222 In consequence of the increase in the quantity of the fibrine and of the increased tendency of the red corpuscles, diminished in quantity, to aggregate together, blood drawn in inflammation presents the buffy coat-an effect produced by the following process, as I have elsewhere explained: the minute process leading to the separation of the liquor san- guinis from the red corpuscles, the visible condition for the formation of the buffy coat, consists in an exaltation both of the rapidity and closeness with which the red corpuscles naturally aggregate into rolls, and these again into a sponge- work, thus squeezing out the liquor sanguinis from among the corpuscles, and allowing the greater specific gravity of the latter 68 RE-ESTABLISHMENT OF THE CIRCULATION. to come more fully into play, whereby the liquor sanguinis, which in such cases is in relatively greater quantity, collects at the top, and coagulating, gives rise to the buffy coat."* B. TERMINATIONS OR EVENTS OF INFLAMMATION. Inflammation terminates either in the healing process or in mortification. a. Nature of the healing process. 223. In the course of the healing process, epiphenomena may occur, which, on account of their prominence and prac- tical importance, are usually spoken of as separate and distinct terminations or events; but the inflammation may not termi- nate on their supervention, and it is obvious that in the abstract they are merely species of the healing process, and this though their tendency may sometimes be to interrupt rather than pro- mote the cure. 224. With this explanation, resolution, adhesion, suppura- tion, and granulation, are to be looked upon as different species of the healing process, in which inflammation may terminate. Only it is to be remarked, in regard to resolution, that it being the immediate and direct process by which the healing of inflammation takes place, it is also truly a termi- nation of inflammation. 225. Inflammation itself, it is known, may, by virtue of the species of the healing process in which it tends to terminate, act as a means of cure of some other disease. Again, one species of the healing process may counteract the wrong direc- tion which another species is taking. Lastly, the termination in mortification itself, may come in as a curative process. 226. As stagnation and exudation are the essential parts of inflammation, so the essential objects of the inquiry into the healing process of inflammation are, how the circulation is re- established in the part, and what becomes of the exuded matter. a. Microscopic phenomena attending the re-establishment of the circulation, and their explanation. 227. Re-establishment of the circulation is observed to take place in consequence of a breaking up of the agglomerations of the red corpuscles, and a loosening of them in the vessels, whereby they yield to the vis a. tergo, and are carried along in the stream of the circulating blood. * Br. and For. Med. Rev., Oct., 1842. RE-ESTABLISHMENT OF THE CIRCULATION. 69 228. The absorption of exuded matter, and the disappear- ance of the red tinge of the adjacent parenchyma, which had resulted from the transudation of hsematin, eventually ensue, and in time the dilated vessels fully recover their usual calibre. 229. In regard to the re-establishment of the circulation, it is, in the first place, to be observed, that though the vessels may be found still dilated, this is not to be assumed as an in- dication that nervous influence has not been again restored to them. The overstretched fibres are unable all at once to con- tract as usual; and as regards the capillaries, they have not re- covered their elasticity weakened by over-distension. 230. The re-establishment of the circulation may be said, in a general way, to depend on the cessation of the disposition which the red corpuscles had to remain aggregated, and to ad- here to the walls of the vessels, in consequence of which they now yield to the vis a tergo. 231. As to the cause of this cessation of the disposition of the red corpuscles to remain aggregated, and to adhere to the walls of the vessels, if the opinion as to the immediate cause of the stagnation of the blood above enunciated, ss. 191, 192, be well founded, it may be naturally inferred that the return of nervous influence to the walls of the vessels is the cause sought for. When, however, the changes in the stagnant blood are taken into consideration (ss. 216,217), it must be admitted that besides restoration of nervous influence, some other cause is in operation. 232. As the apparent fusion of the red corpuscles, which supervenes more or less quickly on stagnation, even when the mass of blood is healthy, is like that which is presented by the red corpuscles of buffy blood, and appears to be owing to the action of plasma inspissated as regards its proteine constituents, but deprived of some of its salts by exudation of serum (s. 217), so the additional cause sought for, may perhaps be found, by comparing with the changes of the red corpuscles in the process of re-establishment of the circulation, those presented by the red corpuscles of buffy blood out of the body, after the coagulable plasma has been by their close aggregation pressed out from among them. The red corpuscles have then lost much of their disposition to remain aggregated, as is shown by the little cohesion of the under part of the clot. This, without going minutely into the matter, may be said to be owing partly to the abstraction of the coagulable plasma from among the red corpuscles, and partly to the direct action on them of the serum, which is by and by separated. The addi- 70 NEW ORGANIC ELEMENTS IN EXUDED MATTER. tion of a saline solution, at the same time that it causes collapse of the distended corpuscles, disposes them to separate. 233. To apply the inference which may be drawn from the comparison now made, in explanation of the process of re- establishment of the circulation in inflammation:—In conse- quence of the abstraction of coagulable plasma from among the red corpuscles, stagnant within the vessels by exudation, and the reabsorption of the serum into the obstructed vessels, the red corpuscles are disposed more readily to separate from each other, and from the walls of the vessels, and thus to yield to the vis a tergo. 234. The fate of the exuded matter constitutes, as above mentioned, one of the essential objects of the inquiry into the nature of the healing process of inflammation, but before pro- ceeding with this inquiry, it is necessary to consider more par- ticularly than has yet been done, the exuded matter itself. |3. Exuded matter. 235. Exudation takes place either into the interstices of the parenchyma, or on surfaces natural or raw, and raw rather. In the case of a natural surface, its epidermis, or its epithe- lium, if it be resisting, is raised up into a blister by the exuded matter. 236. As already said, the exuded matter from being at first serous, comes at last to contain a greater or less quantity of fibrine, and in this state it is a clear viscid fluid usually called lymph. 237. Examined microscopically, the recently exuded matter appears quite amorphous, without any trace of organization. 238. The corpuscles which it is very soon found to contain, are new formations developed after exudation. y. Absorption of exuded matter. 239. If much matter has not been exuded, absorption of it takes place, as the circulation in the obstructed vessels becomes re-established, and this the more readily if the exuded matter is still fluid. 8. Development of organic elements in the exuded matter. 240. When absorption does not take place, the exuded mat- ter becomes organized; in it, as in a blastema, organic elements are formed. The process by which this takes place is altogether the same in principle as that by which the normal development is originally effected. RESOLUTION OF INFLAMMATION. 71 241. There are three principal ways in which the exuded matter has been found to be developed and disposed of. 1. After having attained a certain development, the organic elements are, if formed in the interstices of a parenchyma, dis- solved and removed by absorption, or if formed on a surface, thrown off. 2. The organic elements undergo further development into tissues, homologous or heterologous. The homologous are principally epithelium, cellular tissue and vessels. In regard to new vessels, it is here proper to remark, that it is a not uncommon, though a very erroneous, notion, that many of the vessels which for the first time become visible in an inflamed part—the conjunctiva for instance—at the commencement of inflammation, are new productions. Not only is this not the case, but even in an advanced stage of inflammation, when exuda- tion has taken place, it may be that no new vessels are formed, although the exuded matter undergoes development into other structures. It is also proper to remark, that what is often meant by "organization," is the development of new vessels; but as has been already said, organization of exuded matter may take place quite independently of the development of blood-vessels. The development of new vessels, in fact, is in itself a process of organization which presupposes the development or organization of other tissues. New vessels are not formed for the purpose of "vitalizing" "effusions of the organizable materials of the blood," for such effusions are already vitalized. It is from such effusions that the new blood-vessels themselves are de- veloped, and this along with the development or organization of other tissues, such as the cellular. The blood-vessels are formed in order to fetch and carry away the materials concerned in the nutrition and further development of these tissues. 3. The organic elements formed in the exuded matter are pus-corpuscles, which undergo no further development, but are discharged from the body, in greater or less quantity, along with the fluid in which they are suspended (liquor puris), in the form of pus. 242. The re-establishment of the circulation and the fate of the exuded matter having been considered, a review may now be taken of them in their correlations, as they are exhibited in the different species of the healing process. _. Resolution of inflammation. 243. When resolution of inflammation of a vascular part, visible externally, takes place, the pain and heat cease, the red- 72 HEALING OF A WOUND. ness disappears, the swelling subsides, and the part is at last restored to its natural state. 244. When resolution of inflammation of the cornea above referred to takes place, the irritability of the eye ceases, and, on the one hand, the congestion of the neighbouring conjunctiva and sclerotica diminishes; then, on the other, the exudation in the substance of the cornea disappears. 245. Resolution of inflammation consists in the re-estab- lishment of the circulation, and absorption of the exuded matter. The exuded matter may have been still fluid, and may not have become in any way organized, but it is probable that in many, if not in most cases, apparently ending in resolution (such as it has just been defined), the exuded matter has already attained the first degree of development above referred to, and then again become dissolved in order to be absorbed. £. Healing of a wound. 246. In the healing of a wound, conversion of the exuded matter into tissues takes place under two different kinds of circumstances ; and according as one or the other obtains, there is what surgeons call "healing by the first intention," or by "adhesion," or "healing by the second intention," or by "granulation and suppuration." 247. The stagnation and exudation, and therefore the red- ness and swelling of the part, do not cease on the occurrence of either of these processes. They continue until the healing process is accomplished, the stagnation, or at least a slow circulation in the part, being the necessary condition of exu- dation ; the exudation, again, that of the supply of material wherewith regeneration is effected. 248. The cornea has been above referred to as a part which, from its non-vascularity, forms a good subject for observing, in a manner uncomplicated by the presence of the vessels in which the blood is stagnant, the development and disposition of the exuded matter in the healing process. The matter exuded into the substance of the cornea from the vessels of the adjacent conjunctiva and sclerotica may (as far as examination with the naked eye, or the eye assisted merely by a magnifying glass goes), be seen to undergo the different modes of develop- ment above described. 249. It may be seen that pustules form, and that, in the heal- ing of incisions and ulcers of the cornea, adhesion and granu- lation, and lastly, cicatrization, may take place without the development of new vessels—a convincing proof that neither NATURE OF MORTIFICATION. 73 suppuration nor "organization" necessarily implies the de- velopment of new vessels. 250. But, as above hinted, new vessels may be formed in the matter exuded into the cornea, and this again affords a very interesting and readily observable example of the development of new vessels, uncomplicated by the previous existence of other vessels in the part. 251. The new vessels, having served their purpose, shrink and disappear, and it is usually not until this that cicatrization is completed. 252. Healing by the first intention, or adhesion.—In this case the matter exuded on the cut surfaces becomes forthwith, and all of it, converted into tissues—cellular tissue and capilla- ries—by which the divided parts are reunited. An epithelium or epidermis is then formed on the surface in the ordinary way, and cicatrization is completed. 253. Healing by the second intention, or granulation.— This is a slower process than adhesion. The inflammatory congestion persisting, matter continues to be exuded. One part of it is converted into cellular tissue and capillaries— granulations are composed of these new tissues in process of development; another part is converted into pus, which serves as a sort of epithelium to the granulations. 254. As the healing approaches completion, the quantity of exuded matter converted into pus becomes less and less in comparison with that expended in the formation of tissues. At last, no more pus being formed, the exuded matter is de- veloped into epithelium or epidermis, and cicatrization is in this case also completed. As this takes place, the granulations con- tract and become less vascular by the shrinking and disappear- ance of many of the vessels which existed in them, as is often so distinctly observable in the case of the cornea, in regard to all the vessels. 255. That the tissue of cicatrice is not quite homologous with the old tissue, is very evident in the case of the cornea by the resulting opacity. 256. The newly-formed tissues—whether their formation be by the adhesive process or by granulation—besides effect- ing union of divided parts, or supplying the place of lost parts (reo-eneration), may be formed in excess. In this case hyper- trophy is the result. If the new tissues are heterologous, they constitute tumours of different kinds, induration, &c* * For more detailed observations on Inflammation, and its events, see my Reports in the Brit, and For. Med. Rev., Nos. xxxiv.-v. 74 ACUTE AND CHRONIC INFLAMMATION. b. Nature of mortification. 257. Mortification is the death of the part affected, together with the blood stagnant in it, and the matter which may have been exuded. 258. The proximate cause or the condition on which morti- fication immediately depends, is complete stoppage of the cir- culation ; either from all the vessels of the part being the seat of the inflammatory stagnation, or sometimes together with pressure exerted by the exuded matter, the operation of the pressure being favoured by the mechanical conformation of the part. 259. The dead part being the same as a foreign body, the organization tends to throw it off. The separation is effected by softening of the dead part at its junction with the living. a. Ulceration. 260. The process going on in an ulcerating sore is the oppo- site of that going on in a granulating sore. For whereas, in the latter, the exuded matter is developed partly into tissues, partly into pus, in the former the exuded matter is not only not organized into tissues, but those at the surface of the part lose their vitality, and are thrown off in minute portions with the discharge, which is either a mere sanies, or at the most an imperfectly developed pus. This death of the ulcerating sur- face is not owing to any destructive action of the exuded mat- ter which constitutes the discharge, but is owing to the same condition which determines the death of the exuded matter itself. From this it is seen that ulceration belongs to the head of mortification. C. VARIETIES OF INFLAMMATION. a. Distinction of inflammation into acute and chronic 261. Acute and chronic inflammations are so named from the most striking parts of their character,—the former being distinguished by severity of symptoms, the latter by long con- tinuance. In the acute form of inflammation, with severity of symptoms, there is combined rapidity of progress; and in the chronic form, long continuance is tempered by mildness of symptoms. 262. These differences, it will be observed, are merely dif- ferences in degree and continuance. There does not appear to be any essential difference in nature between the acute and chronic forms of inflammation. In both there is congestion, in both exudation, and in both the exuded matter undergoes INFLAMMATION IN DIFFERENT TISSUES. 75 analogous changes. Moreover, it is to be observed, that be- tween well-marked acute, and well-marked chronic inflamma- tion, all intermediate forms are met with. 263. The conditions on which the striking parts of the cha- racter of acute and chronic inflammation appear to depend, are respectively the following:— In acute inflammation, the congestion is greater; and if re- solution, to which there is a tendency, does not soon ensue, exudation of lymph takes place more or less copiously, the result of which is adhesion, or abscess, or thick puriform dis- charge, as the case may be, after which the circulation may gradually become re-established, and so there is an end of the inflammation* In chronic inflammation, on the contrary, the congestion is less complete—there is but little tendency to resolution—and exudation is either not so copious within a given time, or it is more watery. Moreover, the congestion persists, and the exu- dation still goes on, the result of which is hypertrophies, gleet, &c, as the case may be. 264. The cause of these differences of conditions is, perhaps, that in chronic inflammation, the suspension of nervous influ- ence from the walls of the vessels is less complete, and that the dilatation of the vessels is more of the nature of organic en- largement, than dilatation from simple relaxation and distension, as in acute inflammation. 265. Chronic inflammation may either succeed to acute in- flammation, or come on slowly of itself, unpreceded by any acute stage. Acute inflammation may supervene on chronic inflammation. 266. The tissue affected, the nature of the exciting cause, the state of the constitution, the existence of constitutional disease, &c, are circumstances which exert a modifying influ- ence on the characters of inflammation, and of its events. 267. This is well exemplified in the inflammations of the eye, especially as regards modifications of inflammation ac- cording to the tissue affected. Composed, indeed, as the eye is, of different tissues, and these, for the most part, open to direct inspection, it affords, when affected with inflammation, an especially favourable opportunity for observing, and often for comparing, the modifications of the phenomena of inflam- mation dependent on difference of structure. This circum- stance, at the same time that it facilitates the diagnosis of ophthalmic inflammation, assists the study of inflammation in general. 76 INFLAMMATION IN DIFFERENT TISSUES. b. Modifications of the phenomena of inflammation accord- ing to the tissue affected, as exemplified in the inflamma- tions of the eye. 268. Objective phenomena.—The more vascular conjunctiva, when inflamed, is redder than the less vascular sclerotica; and the non-vascular cornea is not red at all; but the congestion, and consequently the redness attending inflammation of it, are seated in adjacent parts. Redness of the cornea itself, however, may be subsequently superadded by the development of new vessels in it. Lastly, in the coloured iris, the congestion is not manifested by redness, but by a colour a compound of the yellowish redness of a thin stratum of blood and the natural colour of the inflamed structure. 269. Exudation takes place more copiously from the conjunc- tiva and iris than from the less vascular sclerotica, and, cseteris paribus, the exudation is in proportion to the degree of inflam- matory congestion. The exuded matter is for the most part poured out from the surfaces of the conjunctiva and iris, and there are little swelling and thickening, manifesting interstitial exudation, in comparison with the whole quantity of matter exuded ; whereas in parenchymatous structures, the exuded matter being received into their interstices, exudation is mani- fested by more or less considerable swelling. Exudation may give rise to phlyctenular and pustules on the surface of the cornea,—to aphtha? on that of the conjunctiva; a difference which is owing to the difference in the resistance of the epi- thelium investing the two surfaces. Exudation may take place into the cellular tissue underneath the conjunctiva in inflamma- tion of that membrane, in which case a swelling forms, called chemosis. Lastly, in congestion of the sclerotica, there is com- paratively little disposition to exudation, and when it does take place, it is often rather into the neighbouring cornea than into the substance of the sclerotica itself—a peculiarity which seems to hold in the case of other fibrous structures, for example, those around joints in rheumatic gout. 270. From the surface of the conjunctiva, when it is the seat of intense inflammatory congestion, slight hemorrhage readily occurs ; but in less intense inflammation, extravasation of blood occurs in the form of patches of ecchymosis into the loose cellular tissue underneath the sclerotic conjunctiva. Effusion of blood may take place from the surface of the inflamed iris, analogous to the hemorrhagic exudations of inflamed serous membranes — and extravasation may also occur into its sub- INFLAMMATION IN DIFFERENT TISSUES. 77 stance. But in the latter case, as also in that of extravasation into the substance of the cornea, the spots of ecchymosis are small in comparison with those which present themselves in the loose subconjunctival tissue. The readiness with which bleeding takes place from the surface of the conjunctiva, when the seat of intense congestion, is explicable by the exposure to foreign contact of its delicate superficial capillary network in a state of great distension. 271. A modification of the phenomena of the events of in- flammation might a priori be presumed to occur in different structures, in consequence of that physiological difference which determines the mode of assimilation peculiar to each structure. That such a modification holds to a certain extent only, and is readily broken through by modifying influences, is shown by the formation of pus in very different structures, and by the circumstance, that a kind of cellular tissue and blood-vessels are the new structures most commonly regenerated, whatever the original structure may be. 272. An influence which manifestly modifies the manner in which the exuded matter is disposed of, consists in the exposure or non-exposure of it to the contact of foreign bodies, including the external air. The matter exuded on the surface of the con- junctiva in contact with the external air, tends to be converted into pus or puriform matter, whilst that exuded on the surface of the iris out of contact with air, is more disposed to be con- verted into tissue, forming bands of adhesion. 273. The mode in which exposure to the contact of foreign bodies operates in determining suppuration, is probably by their irritation keeping up the congestion, and thus causing exuda- tion in large quantity and of a certain quality. In the cases in which the exuded matter is converted into pus, though not in contact with foreign bodies, the exuded matter has been depo- sited in large quantity, in consequence of the greatness of the congestion from other causes. 274. In the cornea, there may be observed what will perhaps be admitted as an exemplification of the influence of compara- tive quantity of exuded matter, in the disposal of it. When exudation takes place slowly and in small quantity, it is de- veloped into tissues; but when exudation takes place, rapidly and in large quantity, suppuration results. 275. The disposition of the iris to form adhesions with the capsule of the lens, as in the case of serous surfaces, presents a remarkable contrast to the indisposition, which, in common with other mucous surfaces, those of the inflamed conjunctiva 78 INFLAMMATION IN DIFFERENT TISSUES. have to adhere, even when in close apposition, except when abraded, and therefore no longer mucous surfaces. This appears to point to some peculiarity in the matter, considered as a blas- tema, exuded from mucous surfaces. Sometimes, indeed, the matter exuded on mucous surfaces presents itself in the form of pseudo-membranes; these, however, do not become organized, like the pseudo-membranes of serous surfaces, but are eventually separated and thrown off like dead parts. 276. In regard to the formation of adhesions between the iris and capsule of the lens, (synechia posterior,) it has been contended, that the condition for their formation is not exudation of plastic lymph from an inflamed iris alone, but that the cap- sule, as well as the iris, must be in a state of inflammation at the same time. 277. However this may be as regards serous membranes generally, it is to be observed of the case under notice, that since inflammation of the anterior wall of the capsule of the lens con- sists at first merely in exudation into or on it, the exuded mat- ter having its source in congestion of neighbouring parts,'there can scarcely be any difference whether the lymph is exuded from the pupillary margin of the iris, or from the same source as in those cases which are considered to come properly under the head of anterior capsulitis (s. 389). It must be admitted, that synechia posterior occurs in cases in which it would be rather too much to say, that in addition to the iritis, there was anterior capsulitis also. 278. On the other hand, there is great indisposition to the formation of synechia anterior, even when the corresponding surfaces of both iris and cornea are inflamed and in contact, except when there is abrasion of the corneal surface. 279. Of the different structures of the eye, the cornea is that most prone to mortification and ulceration, though perhaps the changes which sometimes take place in the lens and vitreous body might properly be referred to this head. 280. Subjective phenomena.—The most striking modifica- tion of these, perhaps, is the difference of pain. Thus the pain which attends inflammation of the conjunctiva, is like that pro- duced by a foreign body in the eye, whilst the pain in inflam- matory congestion of the sclerotica is of a rheumatic character, and seated around the orbit, in the temples, &c. Dimness of vision attends inflammation of the retina. The various morbid visual sensations are the result of the pressure, irritation, &c, to which the retina is subjected in inflammation of other struc- tures of the eye. ACTION OF REMEDIES IN INFLAMMATION. 79 c. Modifications of inflammation according to the exciting cause. 281. The influence of the exciting cause in modifying in- flammation, appears to consist, sometimes in merely determining inflammation in a particular tissue, as when exposure to cold causes a catarrhal ophthalmia; sometimes, also, in the circum- stance that the exciting cause exerts a specific action, as in the case of the primary action of the syphilitic or variolous poison. ... Modifications of inflammation according to the state of constitution, or the existence of constitutional disease. 282. The influence of the state of the constitution or of con- stitutional disease, appears to consist in modifying the influence of the exciting cause, as regards its operation in determining inflammation in a particular tissue, at the same time that it may impart peculiar characters to the inflammation,—thus, in parti- cular states of constitution, exposure to cold will determine phlyctenular rather than simple catarrhal ophthalmia; or in a constitution tainted with syphilis, for example, it will determine parenchymatous iritis rather than any other form of ophthalmic inflammation. 283. It would, however, be endless, if not impossible, to trace the innumerable combinations of influences modifying inflammation. D. MODE OF ACTION OF REMEDIES IN INFLAMMATION. a. General remedies. 284. From the view of the nature of inflammation, and of the mode of action of its exciting causes, above laid down, it might be inferred, that the remedies which have a direct effect in subduing inflammation, act by determining the vessels to contract, and that through the medium of the ganglionic system. 285. This, indeed, appears to be the action at least of some remedies. As these, at the same time that they promote con- • traction of vessels, call forth contraction of other organic con- tractile parts, so it may be inferred, that other antiphlogistic remedies, which are certainly known to promote the contraction of various organic contractile parts, promote the contraction of vessels also; and this, it may be inferred, is the action by virtue of which they exert their antiphlogistic effects. 286. The depression of the animal vital powers which some 80 ACTION OF REMEDIES IN INFLAMMATION. remedies occasion for the time, might be looked upon rather as a concomitant effect of their action, than as the means through which their antiphlogistic effects are essentially produced. 287. The Italian therapeutists, influenced by the erroneous opinion, that inflammation is a state of increased action of all the parts concerned—that it is an absolute hypersthenia—ex- alted dynamism—describe antiphlogistics as absolutely contra- stimulant or hyposthenisant, reducing the powers of the vessels, as well as of the whole system, by diminishing the force of the ganglionic nerves; whereas they would appear to be hyposthe- nisant of the animal vital powers only, being, in fact, excitants of the contractile fibres of the vessels, and of the organic con- tractile fibres generally, probably through the medium of the ganglionic system. 288. What has just been said of the mode of action of anti- phlogistics, it will be perceived is in the main what is more usually considered to be the action of tonics. The only differ- ence, indeed, between antiphlogistics, properly so called, and tonics, appears to be, that tonics either do not act, or act less energetically in primarily depressing the animal vital powers than antiphlogistics, commonly so called, and more slowly, though more permanently, in increasing the tone of the organic contrac- tile fibre. This shows how that tonics are not incompatible with antiphlogistics. b. Local remedies. 289. The first effect of irritating applications opportunely made to an inflamed surface—the conjunctiva, for example— is a temporary aggravation of the inflammatory state; but by and by this is succeeded by an abatement of the symptoms. 290. The first effect appears to be produced in the same way that inflammation is itself originally occasioned by any local exciting cause. But the mode in which the healthy reaction is thus subsequently promoted, it is not easy to explain. It may be, that the secondary effect of the irritating application on the sensitive nerves is sedative, and that this restores antagonisti- cally the action of the nerves governing the contractions of the walls of the vessels. It is, perhaps, primarily as sedatives of the sensitive nerves, that soothing applications, and also that some general remedies useful in inflammation, act. GENERA OF OPHTHALMIC INFLAMMATION. 81 Section II.—OPHTHALMIC INFLAMMATION IN GENERAL. 291. Ophthalmic inflammations, considered as a class, may be divided into four orders, viz.:— 1. ophthalmia externa. 2. OPHTHALMIA interna anterior. 3. OPHTHALMIA INTERNA POSTERIOR. 4. PANOPHTHALMITIS. 292. The genera of these orders are distinguished and desig- nated according to the particular structure which is the chief seat of the inflammation—I say the chief seat, for the inflam- mation is seldom confined altogether to a single structure. 293. Ophthalmia externa thus comprehends, according as the conjunctiva, sclerotica, or cornea is the chief seat of the inflam- mation, the genera Conjunctivitis, Sclerotitis, Corneitis. 294. Ophthalmia interna anterior, on the same principle, comprehends the genera Aquo-capsulitis, Iritis, * Crystallino-capsulitis anterior. 295. Ophthalmia interna posterior, again, comprehends the genera Choroiditis, Retinitis, Vitreo-capsulitis, Crystallino-capsulitis posterior. 296. Panophthalmitis is both order and genus. 297. The circumstances which principally distinguish and give name to the species and varieties of the ophthalmia., are— 1, the particular part affected of the structure, which is the chief seat of the inflammation—2, the structures which are co- affected—3, the nature of the exciting cause—4, the state of the constitution, or the constitutional disease by which the in- 6 82 INFLAMMATION OF CONJUNCTIVA. flammation appears to be modified—5, the nature of the event of the inflammation. 298. As inflammation is seldom or never altogether confined to a single structure of the eye, but generally involves several at the same time, so a description of inflammation in individual structures would be, as Dr. Mackenzie remarks, a description of a state which seldom or never presents itself separately in nature. Notwithstanding this, it will be useful to premise an account of the characters of inflammation in the individual structures, preparatory to entering upon the description of the varied combinations which present themselves in the ophthal- mia? as they occur in nature. The descriptions will thus admit of being made both clearer and shorter. A. INFLAMMATION AS IT OCCURS IN THE DIFFERENT TISSUES OF THE EYE. 299. In discussing this subject, I will first consider the ob- jective phenomena of inflammation of the different structures of the eye, and then the subjective phenomena. a. Conjunctivitis, or inflammation of the conjunctiva. 300. The principal forms of inflammation, of which the con- junctiva may be the seat—are puromucous, erysipelatous, and pustular or aphthous. 301. Puromucous inflammation of the conjunctiva.—The conjunctiva of the eyelids and of the palpebral sinuses, is deep red. The conjunctiva is also deep red where it is reflected upon the eyeball; but towards the cornea the redness is, at the com- mencement of the inflammation, gradually shaded off.' When, however, the inflammation is fully developed, the redness ex- tends even to the margin of the cornea. 302. The injection of the highly-developed capillary network of the palpebral conjunctiva gives rise to a uniform and intense redness, concealing from view the larger subjacent vessels. Except in a very high degree of inflammation, the injection of the less-developed capillary network of the sclerotic conjunc- tiva does not conceal the larger subjacent vessels. Indeed, what most strikes the observer, is the network with large meshes formed by the intercrossing and inosculation of comparatively large and tortuous vessels, the ramifications of which tend to- wards the margin of the cornea—the arteries and veins which carry the blood to and from the superficial capillary network. 303. In consequence of the accumulation of blood in its ves- INFLAMMATION OF CONJUNCTIVA. 83 sels, the conjunctiva is thickened. The papilla, of the palpebral conjunctiva, being for the same reason swollen and erect, the inner surface of the eyelids has a velvety appearance. 304. The conj unctiva covering the caruncula lachrymalis, and forming the semilunar fold, is deep red like the palpebral con- junctiva, and being at the same time thickened by the accumu- lation of blood in its vessels, both the lachrymal caruncle and semilunar fold appear much enlarged. 305. At the commencement of the inflammation a serous exudation takes place from the surface of the conjunctiva. By and by, a puro-mucous or purulent discharge, the presence of which is an important character of the inflammation, is estab- lished. 306. There is necessarily some exudation into the substance of the conjunctiva itself, producing thickening of it, and en- largement of the papillae of its palpebral portion. 307. In some cases phlyctenular like pins' heads are ob- served on the palpebral conjunctiva, and on the conjunctiva of the sinuses. These are produced by small collections of ex- uded matter, raising up the epithelium. 308. The eyelids, besides being somewhat red, may be more or less swollen, from exudation into their cellular tissue. There may also be exudation into the cellular tissue underneath the sclerotic conjunctiva, raising it up like a wall round the cornea, constituting chemosis. Tumefaction of the eyelids and che- mosis are analogous, in their nature and mode of production, to that swelling which takes place in the neighbourhood of any active inflammation. 309. Ecchymotic spots sometimes present themselves, espe- cially over the sclerotica, in consequence of extravasation of blood into the substance of the sclerotic conjunctiva, or into the cellular tissue underneath. When the inflammation is intense, there may be actual discharge of blood from the surface of the conjunctiva. This more readily takes place from the palpebral portion. 310. From the description now given of puro-mucous inflam- mation of the conjunctiva, it appears that the matter which is exuded from the inflamed surface is converted into puriform mucus or actual pus, though the surface is not ulcerated. On the other hand, the lymph which may have been exuded into the substance of the membrane is developed into tissue, which is the cause of that thickening of the conjunctiva, and enlarge- ment of its papillae, which remain for a greater or less length 84 INFLAMMATION OF CONJUNCTIVA. of time, or even permanently, after the inflammation has sub- sided. 311. Healing process in puro-mucous inflammation of con- junctiva.—Before a puriform or purulent discharge is estab- lished, and before thickening of the conjunctiva and hyper- trophy of its papilla, have taken place, consequently, before exudation has been anything more than serous, resolution of the inflammation may occur. In the contrary case, the return to the healthy state proceeds thus: As vascular congestion, or in other words, the redness diminishes, the sero-mucous or puro-mucous discharge becomes less and less, and any ac- companying chemosis and swelling of the eyelids subside. It is to be remarked, that the vascular congestion of the palpe- bral conjunctiva disappears less quickly than that of the ocular conjunctiva. The papilla? of the palpebral conjunctiva, more- over, are extremely apt to be left in a state of hypertrophy, constituting what are generally called granulations of the con- junctiva. 312. Erysipelatous inflammation of the conjunctiva.—Like inflammation of other mucous membranes, inflammation of the conjunctiva sometimes presents itself with characters between inflammation and oedema. There is considerable infiltration of serum into the substance of the membrane itself as well as into the subjacent cellular tissue. The disease is known by the name of erysipelatous ophthalmia. 313. The most remarkable appearance in this ophthalmia is the watery exudation under the sclerotic conjunctiva, whereby the latter is raised up in folds which protrude like vesicles be- tween the eyelids. The conjunctiva is of a light red color, inclining to yellow, and presents here and there spots of ecchy- mosis, but individual vessels are not readily discernible. The mucous secretion of the conjunctiva is somewhat increased in quantity. 314. Pustular or aphthous inflammation of the conjunc- tiva.—The sclerotic conjunctiva presents one or several small scarlet spots, produced by the convergence of vessels. At the spots mentioned the vessels are large and evident, but as they recede from the spots, they cease to be distinguished by the naked eye; hence the vessels of the red spots appear as if isolated from all connection with any other. By and by, how- ever, the continuity of some of the vessels of the red spots, with those of the rest of the conjunctiva, comes to be distinctly seen. 315. The exuded matter first distinctly manifests itself, whilst INFLAMMATION OF CONJUNCTIVA. 85 in process of metamorphosis into pus, as a small yellow flake in the centre of the vascular spots. 316. In consequence of the little density and cohesion of the epithelium of the conjunctiva sclerotica., it does not, like the epidermis of the skin, retain the exuded matter, but gives way, so that a proper pustule is not formed, but an aphthous spot or small abrasion covered with the exuded matter, becomes pus or puriform, with fragments of epithelium. 317. Pustules often present themselves close to the margin of the cornea. In this case the vessels do not converge from all points to the pustules, but come from the side of the sclerotic conjunctiva only, as indeed was to be expected, seeing that none could come from the cornea on account of its being non-vascular. The thick epithelium of the cornea is at the part opaque and slightly raised by the exuded matter which, with the softened epithelium of the sclerotic conjunctiva of the spot affected, forms, as in the preceding case, the small yellow flake. This form of pustule thus presents a character intermediate between the phlyctenula or pustule of the cornea and the aphthous spot of the sclerotic conjunctiva above described. 318. Besides the red spots from vascular congestion, there may be patches of ecchymosis. 319. Healing process in aphthous inflammation of conjunc- tiva.—Pustules or aphtha? of the conjunctiva may run into ulcera- tion, but in general the spots of vascular congestion disappear, and the abrasion produced by the separation of the epithelium quickly heals, the spot becoming covered with a new epithe- lium, whilst the coating of puriform matter and fragments of old epithelium are thrown off. 320. Mortification and ulceration of the conjunctiva.— Mortification of the conjunctiva, as a consequence of inflamma- tion, does not appear to have been met with, but sloughing of parts of the conjunctiva, in consequence of chemical injury, sometimes occurs. Ulceration, except from a specific cause, seldom takes place. 321. Healing of wounds of the conjunctiva.—Wounds of the conjunctiva gape much, but readily heal. The conjunctiva becomes injected at the edge of the wound, and lymph is ex- uded, which becomes organized in the manner already explained, according as the union is by the first or second intention, one or the other event being in general determined by the apposi- tion or non-apposition of the edges of the wound as in the skin. 322. The palpebral and ocular surfaces of the conjunctiva have no tendency to form adhesions even while kept in close 86 INFLAMMATION OF SCLEROTICA. apposition, unless previously made raw. When abrasion of the surfaces has been produced, especially by burns and escharotics, there is then great tendency to the formation of adhesions. b. Sclerotitis, or inflammation of the sclerotica. 323. The redness is in the form of a pink or lake colored zone, encircling the cornea; the injected vessels of the sclerotica being very minute, and disposed in straight radiating lines, as if from the margin of the cornea, where the tint is deeper, whilst it is shaded off, and disappears towards the orbit—the converse of what occurs in the injection attending conjunctival inflamma- tion. 324. If the vascular congestion be alone taken as inflamma- tion, then it must be said that the part of the sclerotica visible during life through the conjunctiva, is often inflamed; but if ex- udation, and the changes which the exuded matter undergoes, be rather assumed to be indicative of inflammation, then it must be admitted that the sclerotica is comparatively rarely the seat of inflammation. 325. Fibrous tissues in general do not appear to be more fre- quently the seat of the effects of inflammation than the sclero- tica, but are they not as frequently the seat of vascular conges- tion ? Is rheumatism anything more in most cases than vascular congestion in fibrous tissues, with, perhaps, serous exudation into neighbouring parts ? What is called rheumatic ophthalmia appears to be at least nothing more than inflammatory conges- tion of the sclerotica, usually, with more or less implication of the cornea and iris. 326. Rheumatism, or inflammatory congestion in fibrous structures, may at last lead to exudation of lymph either into the substance or on the surface of the part affected,—in the one case giving rise to the thickening and induration of the fibrous structures, in the other, to effusions into the joints or adhesions, such as are met with in pericarditis. By repeated congestions, the sclerotica is indeed left in a somewhat altered state, but it is the cornea or iris which is principally the seat of exudation of lymph and the changes consequent on it, as the joints are in articular rheumatism. 327. The most marked example, perhaps, of the tissue of the sclerotica becoming the seat of changes from inflammation occurs in sclerotico-choroiditis. The first change is a thickened and fleshy appearance of the sclerotica, but its texture becoming at the same time softened, it by and by yields to the distension from within the eye, protrudes and becomes attenuated, and of INFLAMMATION OF CORNEA. 87 a dark color (sclerotic staphyloma). In some cases, however, instead of becoming attenuated and dark, the affected part of the sclerotica actually becomes thickened, and of a dense white pearly appearance. c. Corneitis, or inflammation of the cornea. 328. On account of the non-vascularity of the cornea, there is at first no redness of it from vascular congestion. Con- gestion is not, however, wanting, but is seated in the adjoining conjunctiva and sclerotica, as already explained. 329. That the cornea is the seat of exudation is manifested by opacities of various kinds, phlyctenular, and abscesses. When new vessels are developed in the exuded matter, the cornea then becomes the seat of more or less redness. This, however, is to be distinguished from that which may result from effused blood. When effusion of blood occurs, it appears usually in a patch near the edge of the cornea. 330. One or other of the three principal layers of the cornea may be more particularly the seat of the exuded matter; hence are distinguished inflammation of the proper substance of the cornea, of the conjunctiva corneae, and of the membrane of Descemet. 331. Inflammation of the proper substance of the cornea. In inflammation of the proper substance of the cornea, the vascular congestion is seated in the sclerotica in the form of the sclerotic circumcorneal zone, but sometimes the redness is very slightly marked. There is generally also congestion of the circumcorneal network of the conjunctiva. 332. The exuded matter is deposited either in the interstices of the tissue or on its surface, raising the epithelium in the form of a phlyctenula, or even a blister. 333. The exudation into the interstices of the proper sub- stance of the cornea, may produce map-like patches of dimness, and nothing more. Or the exudation being in greater quantity, a general grayish or yellowish white opacity results, denser at some points than others, and intermixed with red from the presence of new vessels. In this case, the cornea presents a peculiar opalescent appearance. 334. In certain cases there are less exudation and develop- ment of vessels; the cornea still retains a degree of transpa- rency, but is of a dirty yellowish green colour, and rough like ground glass, owing to minute vesicles on its surface, or minute points of ulceration, resulting from the bursting of the vesicles. There is softening of the cornea in all these cases. 88 INFLAMMATION OF CORNEA. 335. When exudation into the proper substance of the cornea, or under the epithelium, takes place rapidly and copi- ously, the exuded matter is generally formed into pus or puri- form matter, and the result is an abscess or a pustule. In such cases the inflammation is more of an acute character than in the preceding. There is more vascular congestion in the conjunc- tiva and sclerotica, so much so, that the cases in question are commonly viewed as examples of corneitis supervening on inflammation of the conjunctiva and sclerotica, while the pre- ceding cases are, on account of the slight appearance of con- gestion in the conjunctiva and sclerotica, viewed as examples of primary corneitis. But from what has been above said of inflammation of the cornea, there is no primary corneitis in the sense here implied, i. e., with vascular congestion first in the cornea. 336. The depositions of yellow matter which occur in the interstices of the cornea at its lower part, and which, on ac- count of their presenting the form of the lunular spot at the root of the nails, are called unguis or onyx, and which are in general rapidly absorbed as the attendant inflammation is sub- dued, have not the character of abscesses like the circumscribed collections of matter which form in the centre of the cornea.— They result from matter exuded into the interstices of the proper substance of the cornea, subsiding to the most depend- ing part like the water in anasarca, whilst true abscesses make their appearance as a densely opaque spot, first white, then yellow, around which the rest of the cornea is more or less opaque from exuded lymph, in which there may be new vessels, as in the walls of abscesses elsewhere. 337. Most frequently the exuded matter is deposited on the surface of the proper substance of the cornea, raising the epithelium in the form of a phlyctenula or blister. The epithe- lium of the cornea being denser, thicker, and more coherent than that of the sclerotic conjunctiva, confines the matter which is exuded, in much the same way that the epidermis of the skin does. The matter being at first a transparent fluid, there is a phlyctenula: subsequently becoming puriform or purulent, there is a pustule. Often the process does not proceed so far as the formation of a pustule. 338. A phlyctenula or pustule of the cornea having burst, a small ulcer covered with puro-lymph is left, which may be compared to the aphthous spot on the sclerotic conjunctiva. A fasciculus of new vessels, extending to this ulcer from the conjunctival circumcorneal network, may make its appearance. INFLAMMATION OF CORNEA. 89 339. Healing process in inflammation of proper substance of the cornea.—When the congestion around the cornea sub- sides, the matter exuded into its substance may gradually be absorbed. And this even when development of it has gone on to the formation of new vessels, though tardily, for the more the exuded matter has been developed, the less readily does it dissolve and become fitted for absorption. The new vessels first disappear, leaving a grayish-white opacity, which clears away from the circumference towards the centre of the cornea, where often more or less opacity remains. 340. A pustule on the surface of the cornea, or an abscess in its proper substance, may disappear by absorption of its contents, leaving, however, more or less opacity; but these collections of matter usually burst, and leave a sore, which may either commence to heal by granulation, or run into ulcera- tion. 341. Inflammation of the conjunctiva cornea.—This usual- ly accompanies acute inflammation of the proper substance of the cornea, or is an extension of inflammation of the sclerotic conjunctiva. . , 342. In consequence of the exudation, the conjunctiva cor- nea becomes at some point opaque and thickened, and here new vessels are soon formed, which, connecting themselves with the conjunctival circumcorneal network—which at the place is in a state of congestion—appear as a mere extension of a fasciculus of vessels from it. The opacity and vascularity may gradually spread across the cornea. . 343. In some cases of what may be called inflammation ot the conjunctiva corneae, there are fewer new vessels and less opacity, but there is superficial spreading ulceration. In cer- tain cases the cornea presents here and there on its surface vas- cular fungous granulations. 344. The changes which the conjunctiva cornea undergoes in inflammation, the thickening and vascularity, are very apt to remain in the forms of pannus, vascular cornea, &c; but often they disappear entirely, and the cornea resumes its natural 345. The coagulation and exfoliation of the epithelium of the cornea, in consequence of chemical injuries, have been mistaken for pseudo-membranous formations. 346. Inflammation of the membrane of Descemet.—iw this inflammation, the vascular congestion is in the sclerotic zone. The exuded matter is deposited between the proper substance of the cornea and the membrane, and generally presents itself 90 INFLAMMATION OF CORNEA. in the form of scattered punctiform opacities. Here also new vessels, when formed, make their appearance. 347. As the inflammatory congestion subsides, the exuded matter is removed by absorption. 348. Ulceration of the cornea.—The cornea is extremely prone to ulceration. The ulceration may be limited to a mere abrasion or exfoliation of the epithelium, or it may affect the proper substance of the cornea also. The membrane of Des- cemet does not appear to be liable to ulceration; but when ex- posed and deprived of support by penetrating ulceration of the proper substance of the cornea, it eventually bursts. 349. Abrasion of the epithelium presents itself either in that form, in which its surface looks like ground glass, or in a form like what is presented after death, when the epithelium begins to soften, and portions of it are detached by wiping the surface. The first form occurs in inflammation of the proper substance of the cornea. The second is rather a result of in- flammation of the conjunctiva cornese ; there is superficial vascu- larity, and the abrasion, like ulceration, has a great tendency to spread; but while it spreads on one side, cicatrization may be seen taking place on another. The cicatrization gives rise to slight opacity. 350. Ulceration of the proper substance of the cornea gene- rally commences by the bursting of an abscess or phlyctenula. Both the bottom and edges of the ulcer may be clear, and the cornea around scarcely, if at all, nebulous. In other cases the bottom of the ulcer is filled with a grayish sloughy-looking mat- ter, which is thrown off to be succeeded by the same thing, whilst the ulcer goes on increasing in depth, and may at last completely perforate the cornea. 351. Hernia of the cornea—(Keratocele).—When an ulcer has penetrated through the proper substance of the cornea, the membrane of Descemet, unable to withstand the pressure from within, is protruded at the bottom of the ulcer, in the form of a small vesicle filled with aqueous humour. This hernia of the cornea usually bursts ere long; the aqueous humour is thus allowed to escape, whereupon the iris falls forward into contact with the cornea, and perhaps a prolapse of it takes place through the ulcerated opening in the cornea. 352. If now a remission of the attending inflammation take place, which is apt to happen, in consequence of the relief of tension produced by the evacuation of the aqueous humour, the ulcerated opening in the cornea heals, the aqueous humour INFLAMMATION OF CORNEA. 91 again accumulates, and the iris returns to its natural position, provided no prolapse of it had taken place. 353. In some cases, when ulceration of the cornea is both broad and deep, but not penetrating entirely through the proper substance, the hernia of the cornea which takes place is large, but still invested with some of the corneal substance. In con- sequence of this it does not so readily burst, but may remain permanent as a thinned and projecting part of the cornea, with impaired transparency, resembling somewhat conical cornea, from which, however, it is to be distinguished. From partial staphyloma it differs in not being connected with the iris, and never being so opaque. 354. By the bursting of an abscess or onyx of the cornea inwards into the anterior chamber, the membrane of Descemet, and the inner part of the corneal substance, are destroyed; the outer part, then, incapable of withstanding the pressure from within, sometimes yields, and forms a prominence of a conical shape. 355. Mortification of the cornea.—The complete death of the cornea and the separation of it in the form of a well-marked leathery slough, are of rare occurrence. The destruction of the cornea, which is so common in the purulent ophthalmia?, takes place in a different manner. 356. The cornea, overlapped all round its margin by the chemosed conjunctiva, may be observed to continue for some time unaffected; but within a short interval it will be found to have become quite opaque and softened. To this succeeds the process of destruction, which consists in that form of mortifica- tion, with small sloughs, which constitutes ulceration. The destruction may involve the whole cornea in its whole thick- ness, or a part only in its whole thickness ; or it may involve a superficial portion only, and this of greater or less size. 357. The immediate cause of all this mischief appears to be the infiltration of the substance of the cornea with exuded matter, and the mechanical pressure exerted by the chemosed conjunctiva, whereby the nutritive movements are more or less completely arrested. 358. Healing of wounds and ulcers of the cornea—by the first intention.—A simple incision of the cornea, in general heals readily. From the vessels of the conjunctiva and sclerotica, which are congested on that side of the cornea next the wound, lymph is exuded into the cornea at the seat of the wound, producing opacity to a greater or less extent, and of more or less intensity. The cut edges are agglutinated by the 92 INFLAMMATION OF CORNEA. exuded lymph, and by its organization continuity of structure is restored. What of exuded matter remains in the substance of the cornea, producing opacity, is gradually absorbed, and the cornea clears in proportion as the injection of the conjuncti- val and sclerotic vessels subsides; a small speck, perhaps, the cicatrice, merely remaining. No new vessels may have been formed in the cornea. 359. By the second intention.—Loss of substance of the cornea, whether produced by ulceration or otherwise, is re- stored by granulation. The granulations may be non-vascular, or they may be vascular, from new vessels which have been developed in the exuded matter, and which have formed a connection with those of the neighbouring conjunctiva and sclerotica. These new vessels generally disappear when the process of granulation is completed, and preparatory to cica- trization. Thus, when an ulcer has filled up by vascular granulations, one vessel after another disappears, until all are gone, leaving an opaque streak where their course in the cornea had been. 360. At first the sore may be swollen, and more or less nebulous at the edges, and discharge a tough, yellow, puro- lymphy matter, which sometimes adheres to it, and hangs down from it in flakes. But when the ulcer begins to heal, its edges become decidedly gray and opaque, and in proportion as it becomes filled with granulations, the quantity of puro- lymphy matter discharged from it becomes less, until none at all is formed. At last cicatrization takes place, and the surrounding nebulosity diminishes until it disappears altogether. 361. The cicatrice is either a permanently opaque spot (leucomd) or it is a clear facet, presenting the appearance as if a small piece had been sliced from the convex surface of the cornea. 362. Effects of penetration of the cornea.—When the cor- nea is freely penetrated by wound, ulceration, or sloughing, prolapsus iridis takes place. 363. According to the size and position of the opening in the cornea, so is the extent of the prolapse of the iris, and so is the pupil more or less involved. The different degrees of prolapsus iridis have received different names; thus, when small it is called myocephalon, from its forming a small black point like the head of a fly ;—when it is a little larger, and flat- tened down by the pressure of the eyelids, it has been compared to the head of a nail, whence the name clavus;—when larger and more prominent, it has been called melon, or apple-shaped INFLAMMATION OF IRIS. 93 prolapse. When the iris is protruded at several openings, the appearance is somewhat like that of a bunch of grapes, whence the name staphyloma racemosum. When prolapsus iridis has taken place, all the symptoms of the attending inflammation are apt to be aggravated. But if the inflammation subsides, and if the opening in the cornea and prolapse of the iris be within certain limits, the latter gradually contracts and flattens as the ulcer of the cornea closes, and nothing at last remains but the cicatrice in the cornea, and adhesion between this and the iris—synechia anterior—with more or less deformed and contracted pupil. If in consequence of a more extensive destruction of the cornea, whether by ulceration or sloughing, the prolapse of the iris have exceeded the limits alluded to, it never collapses, but, as will be by and by shown, lays the ground for the formation of a staphyloma of the cornea and iris, partial or complete. d. Iritis, or inflammation of the iris. 364. In consequence of the coloration of the iris, it does not, like the conjunctiva, for example, when inflamed, appear red, but of a colour which is a compound of its own natural colour and that of the stagnant blood. Thus a blue iris becomes green, a brown iris reddish brown. The brilliancy of the iris is at the same time impaired or lost. Subsequent changes in the colour of the iris are owing to exuded matter and to changes in the pigment. 365. The injected vessels are individually not very evident. Such may sometimes be seen, however, and are to be distin- guished from those of new formation which make their appear- ance at a later stage of the inflammation. 366. The sclerotic circumcorneal red zone is well marked. The conjunctiva may be little or very much injected—so much sometimes as to hide the sclerotic injection. 367. The aqueous humour is at first somewhat increased in quantity by exudation of serum. Exudation of lymph after- wards takes place. Lymph may be exuded on the surface or into the substance of the iris. The exudation from the anterior surface' and from the pupillary margin may be directly seen. Most commonly the exudation takes place first from the pupil- lary margin obstructing the pupil. On the anterior surface the lymph presents itself in drops, and fine flakes of it may often be seen in the aqueous humour, rendering it turbid. 368. The lymph exuded at the pupillary margin soon becomes consolidated and organized, forming bands of adhesion between the margin of the pupil and the capsule of the lens (synechia 94 INFLAMMATION OF IRIS. posterior)—distorting the pupil, and sometimes contracting it to a point. 369. The mode in which closure of the pupil takes place appears to be this: the pupil having been in a state of contrac- tion when the lymph was exuded, the lymph, in consolidating, contracts and draws together more closely the margin of the pupil from which it has been exuded, and to which it is ad- herent. 370. New vessels may make their appearance in the lymph forming the bands of adhesion, in that exuded on the anterior surface of the iris, and also in that filling up the pupil. 371. The lymph poured out at the pupil, forming bands of adhesion, becomes of a brown or yellow colour from the depo- sition of pigment in it. Small red or brown excrescences are also sometimes seen on the inner circle of the iris, or at the margin of the pupil. 372. Though no distinct serous membrane can be demon- strated on the anterior surface of the iris, it thus, like the surface of inflamed organs, which are covered with serous membranes, pours out lymph, which gives rise to adhesions ; but what is peculiar is, that the adhesion which takes place is generally be- tween the iris and capsule of the lens, rarely, if ever, between the iris and the cornea. 373. Parenchymatous inflammation of the iris may be looked upon merely as a more intense degree of inflammation, in which, to exudation on the surface of the iris, there is added exudation into its substance, and that quickly and in large quantity. 374. There is, in acute parenchymatous inflammation of the iris, greater vascular congestion both of the conjunctiva and sclerotica, together with congestion of the choroid, as may be inferred from the accompanying photopsia during life, and from its having been found on dissection after death that there was lymph on the inner surface of the choroid. 375. Exudation into the substance of the iris takes place principally at the pupillary circle, or at the ciliary part, less frequently in the middle. It is manifested by the iris losing much of its natural appearance of structure, and becoming swollen, with its pupillary edge retracted, and its middle bol- stered forward. 376. Abscess is apt to form in such cases when acute. It appears as a small reddish-yellow tubercle on the surface of the iris, generally near its pupillary or ciliary edge, which burst- ing into the anterior chamber, gives rise to a small hypopyon. INFLAMMATION OF CHOROID AND RETINA. 95 The place where the abscess was becomes filled with a black matter, in which case it looks as if the iris were perforated by a false pupil. When the abscess is quite at the ciliary margin, it may evacuate itself externally through the sclerotica, close to the place of its junction with the cornea. 377. Hemorrhagic exudation also occurs in inflammation of the iris. The blood is usually in small quantity, forming a patch of greater or less size on the anterior surface of the iris, and tinging the exuded lymph. 378. Healing process in inflammation of the iris.—As the congestion in iritis subsides, the progress of the absorption of the exuded matter is beautifully seen. Matter which has been recently exuded rapidly disappears; that which has become al- ready organized into adhesions, having to undergo solution by a retrogressive metamorphosis, in order to be fitted for absorp- tion, disappears more slowly; and in many cases the organiza- tion is so complete, that no process of removal takes place. Thickening and change of structure of the iris from exudation into its substance, together with contraction of the pupil and obstruction of it with lymph, are very often permanent. 379. Effused blood is in general readily absorbed, but after repeated effusions some remains unabsorbed, in the form of brown or black masses and patches, at the bottom of the ante- rior chamber and on the surface of the iris. 380. Inflammation of the lining membrane of the posterior chamber or uveitis.—Lymph may be exuded in large quantity into the posterior chamber, on the posterior surface of the iris, and on the anterior wall of the capsule of the lens. The source of this exudation is probably the vessels of the ciliary processes. See further on this head, infra s. 389. e. Choroiditis and retinitis, or inflammation of the choroid and retina. 381. The anatomical characters of the inflammations of the choroid and retina cannot be directly observed during life; even the external redness of congestion proper to them cannot be seen, for, different from the structures hitherto considered, the blood-vessels of those under notice enter the eyeball at its pos- terior part. The cases, moreover, in which there has been opportunity for examination of the eye after death, have in general been such as presented the effects of past inflammation rather than the manifestations of inflammation in progress. But from analogy with what has been seen in inflammation of 96 INFLAMMATION OF THE LENSES. the other structures of the eye, and from what has been observed in the post-mortem examinations referred to, the anatomical characters of inflammation of the choroid and retina may be in- ferred with some degree of probability. 382. Inflammation of the choroid.—The capillary network on the inner surface of the choroid will be more or less injected, and the larger vessels proceeding to or from it, and which are principally seated on its exterior, will be enlarged, so that the choroid will be much increased in thickness, and will press inwards upon the retina and outwards upon the sclerotica. There will be much redness at the posterior part of the sclero- tica, from the injection of the choroidal or short ciliary vessels. 383. Exuded matter will be deposited between the choroid and membrane of the pigment, raising and breaking up the latter, together with the delicate stratum bacillosum of the re- tina, or producing adhesions between the choroid and retina, with alteration of their texture. That something like what is here supposed does really occur is evidenced by what has been found in the few cases in which there has been opportu- nity for examining the eyes after death. Exudation and adhe- sion may also take place between the choroid and sclerotica. 384. If there be intense congestion, such as is presented by the conjunctiva in purulent ophthalmia, a large quantity of mat- ter will be exuded, and suppuration will be the result, with breaking up and disorganization of the whole interior of the eye. But before this, the other internal structures will have become implicated. The case will thus now be one of general ophthalmitis or ocular phlegmon. 385. Inflammation of the retina.—There will be redness of the inner surface of the retina from injection of the ramifications of the central artery of the retina. 386. Exudation will take place between the retina and vitre- ous body, and also into the substance of the vitreous body, and into that of the retina itself. The effect of this is degeneration of the retina, the vitreous body, and subsequently of the pos- terior capsule of the lens. /. Inflammation of the lenses of the eye. 387. These bodies being, like the cornea, non-vascular in the fully developed state, inflammation of them consists at first merely in exudation into or on them; the vascular congestion having its seat in adjacent parts. 388. Inflammation of the crystaline body.—Inflammation of the crystaline body is first evidenced by opacity of the capsule INFLAMMATION OF THE LENSES. 97 resulting from exudation into or on it. In the exuded matter new vessels may be developed. But where is the seat of the primary congestion? This appears to be different according as it is the anterior or the posterior wall of the capsule which is affected. 389. In uveitis, s. 380, the anterior wall of the capsule has often exuded matter deposited on it, in which new vessels are sometimes developed. This is the kind of case described as inflammation of the anterior wall of the capsule. , 390. Whilst inflammation of the anterior wall of the capsule belongs to the head of inflammation of the anterior segment of the eye, what has been viewed as inflammation of the posterior wall of the capsule comes under the head of inflammation of the posterior segment. 391. The vessels described by Walther in the posterior wall of the capsule, radiating from the centre, as indicative of inflam- mation of the part, cannot be, as has been supposed, the en- larged ramifications of the central artery of the vitreous humour, for these have become in the developed eye entirely obliterated. When vessels exist, they must be new formations, developed in exuded lymph. T have not seen any case in which red ves- sels were actually visible; but I have seen radiating streaks of opacity in the situation of the posterior wall of the capsule somewhat similar in arrangement to that of the vessels repre- sented in Professor Walther's figure of inflammation of the pos- terior wall of the capsule. 392. When the capsule of the lens is affected, as above de- scribed, the lens itself becomes more or less altered in conse- quence. It becomes opaque, dissolved, or is even the seat of suppuration. Vessels, it is alleged, have been observed shoot- ing into it from the inflamed capsule. 393. Healing process in the crystaline body.-—Wounds of the crystaline body, it is well known, are in the human eye very generally followed by opacity of the lens. In experiments on brutes this result has occurred in some cases only. As to the capsule, it becomes opaque in the seat of the wound, from exudation depending on the inflammatory congestion which has been occasioned in neighbouring structures by the wound, of which that of the crystaline is necessarily a part only. The wound of the capsule may thus unite. If the wound of the capsule is large, and does not unite, the opaque lens dissolves and disappears. 394. Regeneration of the lens. — Pauli, Lowenhardt and Textor have repeated the experiments on regeneration of the 7 98 PAIN, ETC., IN OPHTHALMIC INFLAMMATION. lens in animals with success. Textor communicates some new cases of regeneration of the lens in man after operations for cataract. The proof that the newly-formed substance pos- sesses the same intimate structure as the lens has at last been supplied by Valentin's microscopical investigation of the sub- ject. 395. Inflammation of the vitreous body.—This does not appear to take place without the posterior wall of the capsule of the lens also becoming affected. Again, though in the fully formed eye there may still exist hyaloid vessels, as described by Arnold and Van der Kolk, the inflammatory changes of the vitreous body, such as deep-seated deposits* of lymph, prin- cipally depend on congestion of the vascular layer of the retina, (s. 385.) 396. Increased or suppressed lachrymation, increased or di- minished Meibomian secretion, are objective phenomena, sympa- thetic with inflammation of different tissues of the eye. 397. The subjective phenomena of inflammation of the differ- ent structures of the eye now come to be considered. In en- tering on this part of the subject, it is, in the first place, necessary to distinguish between the morbid sensations depending on per- version of common sensibility and those depending on perversion of special sensibility. a. Morbid sensations depending on perversion of common sensibility, accompanying inflammation of the different tissues. 398. Conjunctiva.—Like other mucous membranes close to the natural apertures of the body, the conjunctiva is endowed with a high degree of common sensibility; but being loose in texture, the pain which attends inflammation of it is not very severe. There is, however, considerable heat. 399. The most characteristic pain is like that produced by a foreign body in the eye—a sensation which attends inflamma- tion of other mucous membranes near the surface of the body. The sensation as if a foreign body were in the eye is owing to enlargement of the vessels on the one hand, and to increased sensibility of the conjunctiva on the other. 400. Attendant on inflammation of the conjunctiva there are also itchiness and smarting at the edges of the eyelids, with occasional stitches of pain shooting from them. 401. Sclerotica.—Very severe pain of a rheumatic character around the orbit, in the temples, &c, is a characteristic of sclero- MORBID VISUAL SENSATIONS. 99 tic inflammation or congestion, owing either to accompanying congestion in the parts mentioned, or to nervous irradiation. 402. Cornea.—The sensation in the cornea itself is one of pressure. But as inflammation of the cornea is attended with injection of the conjunctiva and sclerotica, there may be also the sensation of a foreign body in the eye peculiar to the former, and the rheumatic pain peculiar to the latter. 403. Iris.—When the iris is inflamed, there is necessarily more or less sclerotic congestion, hence the sclerotic rheumatic pain which so often accompanies iritis. As to the pain within the eyeball Itself, it may be accounted for as much perhaps by the distension to which the exterior tunics are subjected by the increased accumulation of blood and fluids in the interior of the eye, as by supposing it to be seated in the iris, which indeed does not appear to possess much sensibility. 404. Choroid.—The choroid itself does not appear to be endowed with any sensibility. The pain which attends inflam- mation of it being probably owing to the distension of the eye- ball, and to attending congestion of other parts. 405. Retina.—The morbid sensations depending on perver- sion of common sensibility, which may attend inflammation of the retina, have not their seat in the retina, but are merely owing to distension of the eyeball, and accompanying congestion of other parts. b. Morbid sensations depending on perversion of the special sensibility of the retina. 406. When nervous structures endowed with special sensa- tion are irritated, the sensation produced is not pain, but various modifications of the sensation peculiar to the structure, and this whatever be the irritating agent. Thus when the retina is in a morbidly sensible state, irritation of it by light gives rise to a dazzling glare, which is so distressing, that the patient seeks to protect the eye against light: this constitutes intolerance of light, or photophobia. But even in the dark the same dazzling glare, or various kinds of luminous spectra, may be produced by pressure, &c, and that in a degree more or less distressing, according to the morbid sensibility of the retina, and the intens- ity of the pressure or other irritating cause: this constitutes photopsia. 407. The appearance of a gauze or mist, or " a skin with veins in it," appears to be the proper subjective effect of the congestion and exudation in inflammation of the vascular layer of the retina. 100 CAUSES OF OPHTHALMIC INFLAMMATION. 408. The other special morbid sensations, photopsia, a mor- bid sensibility to common impressions, and photophobia, occur rather as accompaniments of inflammation of other structures of the eye than of the retina itself. Thus the morbid sensi- bility of the retina on which intolerance of light depends, is an accompaniment of those acute inflammations in which the cor- nea is especially involved. Luminous spectra again appear to be especially occasioned in inflammation of the choroid, by the pressure arising from the congestion and exudation. This is illustrated by the well-known effect of pressure with the point of the finger on the exterior of the eyeball. B. CAUSES OF OPHTHALMIC INFLAMMATION. 409. The practical advantage of being acquainted with the causes of ophthalmic inflammation is to know how to avoid them, and thus to prevent the inflammation, or, if they have already produced ipflammation, to know how to remove them if still in operation and removable. 410. The causes of ophthalmic inflammation may be referred to three heads,—viz.—1st. Those which operate directly on the eyes. 2d. Diseases of other parts with which the 'eyes sympathize, or which spread to the eyes. 3d. States of con- stitution and constitutional diseases which, though they do not necessarily determine inflammation of the eyes, at least predis- pose them to be affected by other causes. 411. To the first head belong:—Direct injuries—direct in- fluence of cold—the direct action of very strong light, or of this and strong heat together—the irritation of reflected light— over-exertion of the sight, especially in bad light, either too weak or too strong, with much stooping of the head—the direct influence of acrid vapours,—epidemic or endemic influences- trie direct application of contagious matters. These are all exciting causes; but some of them require to be assisted by other causes, so that they operate partly as predisposing causes also. :4 412. To the second head belong diseases of the skin, espe- cially the exanthematous diseases. 413. To the third head belong the scrofulous, rheumatic or gouty diathesis, and constitutional syphilis. 4*4. Under the influence of these causes, different forms of ophthalmic inflammation are produced. TREATMENT OF OPHTHALMIC INFLAMMATION. 101 C. TREATMENT OF OPHTHALMIC INFLAMMATION. 415. In consequence of the peculiarity of the structure and functions of the eye, its usefulness is apt to be interfered with by such effects of inflammation as in most other organs would be of little or no moment. Hence, though the treatment of ophthalmic inflammation must be conducted on the same gene- ral principles as that of inflammation of any other part of the body, it is necessary, caeteris paribus, to push it with more activity, and at the same time to attend to numerous special details. Thus in iritis, blood-letting and mercurialization re- quire to be pushed to a greater extent than might in another organ be thought advisable for the same kind and degree of inflammation. But supposing blood-letting and mercurialization thus pushed have been successful in subduing the inflammation, the neglect of such details as the application of belladonna to keep the pupil dilated, may have allowed it to become closed, or the lens spotted over with depositions of lymph, in which case vision will be lost or greatly impaired. 416. In the treatment of ophthalmic inflammation, the first points to be attended to (besides, as a matter of course, the removal of the exciting cause, if still in operation and remov- able), are the protection of the eyes from everything which can cause or keep up irritation—such as using them or ex- posing them to strong light—and the avoidance of whatever is calculated to operate injuriously on the system in general, such as exposure to the weather, corporeal exertion, errors of diet, <__e. 417. When ophthalmic inflammation is sympathetically con- nected with disease of some other organ, as the exanthematous ophthalmia? are with the inflammation of the skin, or sympto- matically connected with some general diathesis, as scrofula, or disease, as syphilis, the treatment of the ophthalmic in- flammation ought not to be delayed until the removal of the disease with which it is sympathetic, or of which it is symp- tomatic. & 418. It is true that the local disease cannot always be cujr€jju or alleviated until the removal of the general disease, and ^fat the removal of the general disease, will, of itself, often dete^iine the subsidence of the local. This, however, ought no^o pre- vent us from at least attempting to relieve the eyes aavmickly as possible. Ar 419. For the cure of ophthalmic inflammation, a^for that of / 102 TREATMENT OF OPHTHALMIC INFLAMMATION. inflammation generally, different plans of treatment are required according to the structure or structures affected, the degree and stage of the inflammation, &c. 420. The treatment of ophthalmic inflammation is divided into general and local, of each of which there are two principal plans. The two principal plans of general treatment are—the antiphlogistic, properly so called, including mercurialization,— and the tonic and alterative. These two plans may be variously modified and combined, according to the circumstances of the case. The two principal plans of local treatment are—the antiphlogistic and soothing,—and the irritating or stimulant. These again may be variously modified or even alternately employed according to the circumstances of the case. a. General.—a. Antiphlogistic treatment. 421. General bleeding.—This is often required in acute ophthalmia, whether external or internal. Incompressibility of pulse, hot skin, and white tongue, are the general indications of the propriety of bleeding. The objective and subjective states of the eye will often of themselves furnish indications irrespective of those just mentioned. Circumorbital pain, for example, is a good indication; for when an ophthalmia is attended by it, venesection in general soon gives relief and pro- motes the operation of other remedies. 422. It is to be remarked that when circumorbital pain is severe, and has already continued some time, there may be a state of depression. This, however, ought not to forbid the abstraction of blood: on the contrary, venesection, by relieving the pain, removes the state of apparent depression. 423. The quantity of blood abstracted must depend on the nature of the inflammation and the strength of the patient__ from ten to twenty ounces may in general be safely taken. Nor need a repetition of the abstraction of the same quantity be dreaded. In severe inflammation, the system in general tole- rates a greater abstraction of blood as it does larger doses of tartar emetic, &c. 424. Cupping may sometimes be employed to supersede venesection, but in general, cupping is more applicable in chronic internal ophthalmia—cases in which the tonic and alterative plan of treatment is indicated. , 425. In acute internal inflammation, by trusting to cuppiru? the system may be drained of blood without any advantage to the eye; but, on the contrary, the cure will be protracted and the vessels of the organ left weak and relaxed, so that they will TREATMENT OF OPHTHALMIC INFLAMMATION. 103 be for a long time liable to become congested from the slightest cause. 426. The advantage obtained from bleeding is not so much the mere depletion as the impression made on the nervous system. This venesection effects more decidedly than cupping. 427. Mercurialization.—In the internal ophthalmia?, mer- cury is an indispensable remedy. In acute iritis, for example, when the system is brought under the influence of mercury, the inflammation is in general observed to abate, and as this abatement goes on, the effused lymph becomes absorbed. The operation of the mercury is promoted by combination with opium, and by the preceding venesection. 428. The action of mercury is commonly described as sim- ply sorbefacient; but it appears to be sorbefacient merely because it subdues the inflammation, which has caused the exudation or the congestion which prevents the absorption. 429. Mercury is both antiphlogistic and tonic, contra-stimu- lant, or hyposthenisant, as the Italian therapeutists affirm; but how does it act—primarily on the organic contractile fibre, or primarily on the blood, or on both at the same time 1 430. Turpentine has been employed with considerable suc- cess in iritis and some forms of corneitis, but it is not so certain a remedy as mercury. 431. Emetics, purgatives, diaphoretics.—The antiphlogistic powers of tartar emetic are not, perhaps, so strikingly displayed in ophthalmic as in pulmonary inflammation; considerable ad- vantage is, however, often obtained from it. The treatment of the phlyctenular ophthalmia of children, for example, is often very materially assisted by tartar emetic, first in emetic, and afterwards in nauseating doses. 432. As regards the use of purgatives in ophthalmic inflam- mation, it is to be observed, that it is sometimes only after a free action on the bowels that a decided abatement of the inflam- mation takes place. 433. In general, however, it may be said, that emetics and purgatives are not to be trusted to as a principal means of cure in ophthalmic inflammation. This is still more applicable to diaphoretics. 434. Nitre is a favourite remedy in inflammation, generally. It has been of late highly recommended in ophthalmic inflam- mation, sometimes, even, in preference to mercury and tartar emetic; not affecting the gums like the former, nor causing vomiting like the latter.* * Rognetta, Traite philosophique et clinique d'ophthalmologie has. sur les principes de la therapeutique dynamique. Paris, 1844. 104 TREATMENT OF OPHTHALMIC INFLAMMATION. 435. Belladonna.—This is a most important medicine in the treatment of ophthalmic inflammation. It is employed to keep the iris contracted in iritis, and thus to oppose the tendency to closure of the pupil, and to prevent depositions of lymph on the middle part of the anterior capsule and synechia posterior. Against intolerance of light, and especially that which is so distressing a symptom in phlyctenular ophthalmia, it sometimes acts like a charm. 436. But besides these effects, belladonna appears to exert an influence in subduing the inflammation itself. Indeed, in respect of antiphlogistic powers, the Italian therapeutists have compared it to bleeding, tartar emetic, &c, though from neglect of the important distinction above laid down, (s. 287,) they appear to me to describe its mode of action inaccurately, not only in inflammation, but also in dilating the pupil. 437. As to the mode of action of belladonna in dilating the pupil, seeing that the state of relaxation of the iris is that in which the pupil is neither much contracted nor much dilated, and that contraction and dilatation of the pupil are manifestations of an active state, the former of the circular, the latter of the radiating fibres of the iris, it is to be inferred, that the action of belladonna, in producing dilatation of the pupil, consists in call- ing forth, through the medium of the ganglionic system, the contraction of the radiating fibres. These fibres, it is to be remarked, are, different from the circular fibres, immediately under the influence of the ganglionic system. 438. If such be the action of belladonna in dilating the pupil, it is more than probable that its power as an antiphlogistic, consists in determining contraction of the vessels, they being, like the radiating fibres of the iris, under the influence of the ganglionic system. 439. The action of belladonna, in producing dilatation of the pupil, probably consists in exciting, through antagonistic reflex action, the nerves of the radiating fibres of the iris, by exerting a sedative influence on the retina. The contraction of vessels, which I suppose to be called forth by belladonna in inflamma- tion, may be due to a similar sedative influence on sensitive nerves,-—in consequence of which, the action of the nerves governing the contraction of the vessels, is by antagonism re- stored. The relief of intolerance of light by belladonna, ap- pears to be produced by its sedative influence on the retina. j3. Tonic and alterative treatment. 440. Tonics are of extensive use in ophthalmic inflammation TREATMENT OF OPHTHALMIC INFLAMMATION. 105 —sometimes to promote convalescence, after inflammation has been subdued by depletion and mercurialization—sometimes even in the height of the inflammation; thus in the scrofulous ophthalmia, quina has been shown by Dr. Mackenzie to be scarcely less efficacious than mercury is in iritis. Iron, zinc, and the mineral acids, are also useful in various cases, compli- cated with anaemia, dyspepsia, &c. 441. In chronic internal ophthalmia, mercury, as an alterative, given in conjunction or not with sarsaparilla, quina, &c, is a most useful remedy—also arsenic. b. Local.—a. Antiphlogistic and soothing treatment. 442. Local bleeding—Leeches.—Though in acute internal ophthalmia, leeches would not produce a very decided effect, they may often be usefully made to follow up venesection. Leeches alone are applicable in ordinary cases of conjunc- tivitis, corneitis, &c. 443. Scarification is very beneficial when the vessels of the palpebral conjunctiva are much gorged with blood, as in the purulent ophthalmia?. When chemosis is present, incisions are made in the elevated conjunctiva, or folds of it are snipped off, as above directed, (s. 152;) but as much for the sake of reliev- ing tension as for the abstraction of blood. 444. Evacuation of the aqueous humour.—This has been recommended as a remedy in ophthalmic inflammation. It operates, by relieving distension of the eyeball from increased accumulation of aqueous humour—a state attended by suffu- sion of the cornea, and the cause at once of considerable distress, and of a continuance of the inflammatory action. The practice is certainly sometimes advantageous, but the aggregate results have been on the whole not very favourable; moreover, the operation is too nice a one to warrant its adoption, except on particular occasions, (see s. 176.) 445. Counter irritation is of much use in ophthalmic in- flammation, after the acute symptoms have been subdued, and in chronic inflammations. 446. Cold and warm applications.—The cases in which cold applications are adapted, are conjunctivitis in its earlier stages, and injuries of the eye, in order to ward off or moderate the traumatic inflammation. In most other cases of ophthalmic inflammation, warm applications are preferable. But it is to be observed, that the choice of cold or warm applications may be in general best determined by the feelings of the patient. 106 THE OPHTHALMLE. 0. Irritating applications. 447. It may be laid down as an axiom, that (to use the words of Dr. Mackenzie) in the internal ophthalmia?, and es- pecially in the acute stage, the application of stimulants is use- less or destructive; while in conjunctival inflammations, more is effected by their means than by almost any other kind of remedy. Indeed the plan of treatment adapted for acute iritis, if trusted to in severe conjunctivitis, would expose the eve to almost certain destruction. 448. But in regard even to conjunctival inflammations, it is to be observed, that as they are frequently dependent on the state of the constitution, or on an affection of some other organ, he who in treating them should direct his attention exclusively to the eye affected, might often exhaust his whole ophthalmic formulary in vain. On the other hand, however, it is not to be denied, that in many cases the inflammation is either purely local, or though connected with constitutional causes, can have its cure effected only by local treatment. This must not be overlooked; for though it has been more usually the error to treat ophthalmic inflammations as mere local affections, still some practitioners have run into the opposite extreme of neg- lecting local treatment entirely. 449. For observations regarding the mode of action of local remedies, see ss. 289,290. Section III.—THE OPHTHALMIA. a. Order I.—ophthalmia externa. 450. The order of ophthalmia externa comprehends the genera conjunctivitis, sclerotitis, and corneitis. Each of these as has been shown, maybe more or less complicated with some degree of the other; but when the conjunctiva and sclerotica or conjunctiva and cornea, or the conjunctiva, sclerotica and cornea, are equally affected at the same time, then the case must be considered as coming under the head of a fourth Lnus viz., compound external ophthalmia. h genUS) CATARRHAL OPHTHALMIA. 107 a. Genus I.—conjunctivitis. 451. The species of conjunctival ophthalmia are:—puro- mucous ophthalmia—erysipelatous ophthalmia—and pustular or aphthous ophthalmia. 452. Puro-mucous ophthalmia.—The different forms or varieties of puro-mucous ophthalmia are :—catarrhal ophthalmia —Egyptian or contagious ophthalmia—ophthalmia neonatorum —gonorrhoeal ophthalmia,—to which may be added the oph- thalmia sometimes met with in female children in connection with puro-mucous vaginal discharge. Catarrhal ophthalmia. (Blepharophthalmo-Conjunctivitis catarrhalis—Ophthalmia purulenta mitior.) 453. The form of inflammation comprehended under this name, is usually considered the type of conjunctival inflamma- tion ; for it is the form which inflammation of the conjunctiva, excited by other causes besides atmospherical influence—in- jury, for example—is most prone to assume. 454. Objective symptoms.—The eyelids are somewhat red and swollen, especially at their edges—the upper eyelid may- be so much swollen as to overlap the edge of the lower. The white of the eye is bloodshot, and on examination, this is found to be owing to the reticular vascular injection above described as characteristic of inflammatory congestion in the conjunctiva, (ss. 301-302.) Besides the vascular injection, there are sometimes interspersed spots of ecchymosis, (s. 309.) 455. On everting the lower eyelid, it is seen, that towards the palpebral sinus, the redness of the sclerotic conjunctiva is more intense, and that the palpebral conjunctiva, at the same time that it is very red, is thickened and velvety-looking. The semilunar fold and lachrymal caruncle are red and swollen. 456. In the severer cases, in which the vascular injection of the sclerotic conjunctiva extends to the very margin of the cornea, there may be some degree of chemotic elevation of the conjunctiva, especially at the lower margin of the cornea. 457. The cornea may remain quite clear, and the colour and activity of the iris unchanged. 458. There is at first watering of the eye, the result, partly, of the serous exudation from the conjunctiva, above mentioned, (s. 305,) but by and by a puro-muculent discharge takes place. The matter accumulates in greater or less quantity at the inner 108 CATARRHAL OPHTHALMIA. corner of the eye, and in flakes in the palpebral sinuses. Films of this matter getting on the surface of the cornea every now and then, occasion momentary dimness and iridescence of vision. The eyelashes, also, are besmeared with the secre- tion ; but another source of the matter, which is found incrust- ing them, and gluing the eyelids together over night, is the secretion of the Meibomian glands, which is poured out in increased quantity. 459. The watering of the eye at the commencement, as has been hinted, does not appear to be wholly the result of lachryma- tion, but partly of serous exudation from the congested vessels of the conjunctiva. A flood of tears, however, occasionally takes place. 460. Subjective symptoms.—Itchiness and smarting at the borders and angles of the eyelids, heat, and the sensation as if a foreign body were in the eye, are the subjective symp- toms which usually usher in an attack of catarrhal ophthalmia. 461. There is not much intolerance of light, though there is a greater or less desire to shade the eye, and a feeling of weakness of it. The eyelids feej stiff, heavy, and tense. When the upper overlaps the lower, a very disagreeable sensa- tion is experienced. 462. The discharge of tears which occasionally takes place, is followed by temporary relief; and when the puro-mueulent secretion is established, the itchiness and smarting of the edges of the eyelids, and the sensation as if a foreign body were in the eye, are relieved. 463. There may be pain across the forehead, and in the re- gion of the frontal and maxillary sinuses, but there is no pain like rheumatism around the orbit nor in the temples. 464. An exacerbation of the symptoms takes place towards evening; but the sensation as if a foreign body were in the eye, is felt much on first moving the eye in the morning. 465. Constitutional symptoms.—In general, there is not much or any constitutional disturbance; but the patient may be at the same time affected with a general catarrh. 466. Predisposing causes.—The patient may be of any a_re, of either sex, and otherwise healthy; but it is often the case that he has been for some time out of health, or has been over- exerting the eyes. 467. Exciting causes.—-This form of inflammation, though conventionally called catarrhal, may be excited, as above men- tioned, by irritation or injury of the conjunctiva. It is b the CATARRHAL OPHTHALMIA. 109 majority of cases, however, excited by atmospheric influence. In this case it may occur epidemically. In some places it is so common, that it might be considered endemic. Under these circumstances, it is usually of a very severe form, par- taking more of the characters of Egyptian ophthalmia in its milder degrees—like which, also, it sometimes appears to spread by contagion. 468. Very generally both eyes are affected, but one is usually more so than the other. 469. Diagnosis.—Simple catarrhal ophthalmia is, in gene- ral, distinguished from the other forms of puro-mucous ophthal- mia, in not presenting such a degree of redness and swelling of conjunctiva, copiousness of the puriform discharge, nor swell- ing of the eyelids, and by the circumstances under which it occurs. 470. The ophthalmia? from which catarrhal ophthalmia re- quires to be principally distinguished, are phlyctenular and catarrho-rheumatic,* the former occurring in young persons, the latter in adults. 471. In phlyctenular ophthalmia, the conjunctival vessels which are injected are few in number, and ramify singly or in detached fasciculi towards the conjunctival circumcorneal net- work, (s. 625,) which may be completely, or partially injected. There is also some sclerotic circumcorneal injection. The general expression of the redness in phlyctenular ophthalmia is thus different from what obtains in catarrhal ophthalmia, a faint blush on one side or all round the cornea, shaded off to- wards the circumference of the eyeball, together with a fasci- culus of vessels, perhaps, proceeding to some point on the cornea where there is an ulcer. 472. In phlyctenular ophthalmia, the cornea, which is the essential seat of the disease, early becomes suffused, or presents phlyctenula?, which, bursting, leave ulcers. In catarrhal oph- thalmia, although ulceration of the cornea may eventually take place, the cornea is quite unaffected at first. 473. In phlyctenular ophthalmia there is little or no in- crease of the Meibomian secretion, or of the mucous secretion of the conjunctiva, which are such prominent characters in catarrhal ophthalmia. But in phlyctenular ophthalmia there are great lachrymation and intolerance of light; whereas in * Catarrhal ophthalmia is not likely to be confounded with rheumatic oph- thalmia or sclerotitis. The difference in the seat and character of the vascu- lar injection has been above pointed out, (ss. 63, 323,) and the difference in the accompanying pain, (ss. 2, 394-395.) no CATARRHAL OPHTHALMIA. catarrhal ophthalmia, these symptoms are slight or altogether absent. 474. But it is to be remarked, that phlyctenular and catar- rhal ophthalmia? may occur in combination, constituting scro- fulo-catarrhal ophthalmia. Catarrhal may also occur in com- bination with pustular or aphthous ophthalmia. Cases even occur of a combination of catarrhal, aphthous, and phlyctenular ophthalmia. 475. The differences between catarrhal and catarrho-rheu- matic ophthalmiae are:—In catarrhal ophthalmia, there is simply conjunctival injection—in catarrho-rheumatic, both conjunctival and sclerotic. Hence, while in catarrhal ophthalmia, the scle- rotica is observed white under the vascular network of the con- junctiva, it is pink in catarrho-rheumatic ophthalmia. 476. While in catarrhal ophthalmia, unless severe and of long continuance, the cornea is clear, and the colour and mo- tions of the iris natural, in catarrho-rheumatic ophthalmia, the cornea appears muddy, and not unfrequently presents a phlyc- tenula or ulcer, and the iris is discoloured, and pupil sluggish. There is considerable intolerance of light in catarrho-rheumatic ophthalmia; and instead of the pain across the forehead, or in the frontal sinuses, which may exist in catarrhal ophthalmia, there is more or less severe circumorbital or temporal pain, aggravated when the patient is warm in bed. 477. Prognosis.—Catarrhal ophthalmia, in its simpler forms, is in general readily subdued. In its severer forms, if neglected or improperly treated, ulceration of the cornea may take place, and, above all, the palpebral conjunctiva is extremely apt to be left in a state of chronic inflammation—itself thickened, and its papillae enlarged—a state which keeps up irritation of the eye, and which.may lead to vascularity and opacity of the conjunctiva cornea?. In this, as also in the other puro-mu- cous ophthalmia?, entropium and ectropium are not unfrequent rcfeu.1 ts • 478. Treatment.—In the simpler forms of this ophthalmia, it the case is seen at the very commencement, an attempt should be made to subdue the inflammation by soothing treatment. for this purpose, rest, quiet, and restricted diet should be en- joined and a purgative of calomel and jalap, for example, pre- scribed; or an emeto-cathartic, especially if there is more than usual sensibility to the light,-two grains of tartar emetic, and an ounce of Epsom salts, may be dissolved in half a pint of water, and two or three tablespoonfuls of the solution taken CATARRHAL OPHTHALMIA. Ill every half hour until vomiting; after which the same dose every four or six hours only. 479. As applications to the eye, lotions of tepid water three or four times a day, or, if more agreeable, the continued appli- cation of cold. The continued application of cold lotions, however, it is to be remarked, is apt, in middle-aged persons particularly, to excite sclerotic inflammation, and thus convert a catarrhal into a catarrho-rheumatic ophthalmia. As an occa- sional application, cold water is not well adapted. When used as such, an uncomfortable sensation of heat in the eye is felt soon after ; whereas, when tepid water has been used, the eye for a time feels pleasantly cool. At bed-time, the borders of the eyelids are to be anointed with simple ointment. 480. Under this soothing treatment, the inflammation will sometimes subside without anything further being required; but if it does not begin to do so within twenty-four hours or so, irritating collyria will require to be used. The nitrate of silver solution, for example, may be dropped into the eye once a day, and the alum, bichloride of mercury, or lapis divinus lotion, without addition of vinum opii, (s. 124,) used tepid, to bathe the eye three times a day. At bed-time, the borders of the eyelids may be anointed with the weak red precipitate salve, (s. 136). 481. If, notwithstanding this treatment, the inflammation persists, it will be proper to apply leeches—from six to twelve around the eye, or each eye, if both be affected. 482. In the severer forms of the complaint, blood should be at once abstracted, either by leeches as above, or if the patient be robust, by venesection, followed up, if necessary, by leeches. This treatment will save much subsequent inconvenience from a thickened state of the palpebral conjunctiva. After the bleed- ing, a pediluvium, and some diaphoretic, such as Dover's powder, at bed-time, are to be prescribed, and a purgative draught in the morning. After that, nitre in doses of gr. v every two or three hours, in barley-water. Locally, the same treatment as above indicated. 483. As the inflammation remits, the redness of the sclerotic conjunctiva becomes less and less until it has quite disappeared ; but though this has taken place, considerable congestion may still be presented by the palpebral conjunctiva, with enlargement of its papilla?. If this state of the palpebral conjunctiva con- tinue obstinate, blisters behind the ears, scarification of the pal- pebral conjunctiva, and the penciling of it with the strong red precipitate or nitrate of silver ointment, will be useful. When 112 EGYPTIAN OPHTHALMIA. the palpebral conjunctiva is merely left relaxed and thickened, penciling it a few times, at intervals of two or three days, with vinum opii, pure, or diluted with one or two waters, or with the lapis divinus drops, will do good. A return to generous diet, and the use of tonics, are at the same time to be enjoined. Egyptian ophthalmia. Ophthalmia vel conjunctivitis puromucosa contagiosa—Ophthalmia purulenta gravior—Ophthalmo-blennorrhcea—Ophthalmia bellica, &c. 484. This is the disease of the eyes which so severely af- fected the English and French armies in Egypt, and also after their return thence, and which has since raged in the armies of almost all the states of Europe. 485. The palpebral conjunctiva is especially the focus of the disease ; being the part which is from the first, and which con- tinues to the last affected, whatever other parts may be also involved. But though the inflammation may thus remain almost entirely confined to the palpebral conjunctiva, it is peculiarly disposed to extend, and that with great violence, to the ocular conjunctiva, and even to the proper tunics of the eyeball itself. On this extension of the inflammation depends the rapid de- structiveness to the eye, which has so lamentably characterized the disease. 486. Different degrees of the ophthalmia—a first, a second, and a third degree—are accordingly recognized. 487. In the first degree, the inflammation is still in a great measure confined to the palpebral Conjunctiva, and, though there is some puro-mucous secretion, there is no decided blen- norrhoea. 488. In the second degree, the inflammation has extended to the ocular conjunctiva, which is loosened and raised up into chemotic folds at the lower edge of the cornea, and there is more or less blennorrhoea. 489. In the third degree, the chemosis is complete, the eye- lids are enormously swollen, there is profuse discharge of muco- purulent matter and the proper tunics of the eyeball are either !ony ^°^ed' °r in imminent danger of becoming so. 490. The disease may not advance beyond the first degree, but become chronic, or it may at once pass into the severer tiono'f'nn^1'8, ^ state'itis Already, on the applica- nt ^7 excihnS "use, to pass into the severer degrees. iyi. Ihe second degree may arise at once as -,,£», nrU developed from the first degree. U°h' °r be EGYPTIAN OPHTHALMIA. 113 492. The second degree has a great tendency either to be- come chronic or to pass into the third degree, and this espe- cially if neglected or improperly treated. The third degree, indeed, generally, if not always, arises by a sudden aggravation of all the symptoms from the milder degrees, especially the second. 493. The morbid development on the surface of the palpebral conjunctiva of what are called granulations, is an early and important effect of the inflammation. 494. Besides granulations, phlyctenula?, in some cases, pre- sent themselves, in the beginning of the disease, on the palpe- bral conjunctiva, and on the conjunctiva of the sinuses. The nature of these phlyctenula?, as well as that of the granulations, has been above pointed out, (ss. 303-6-7-10-11.) From what is there said, it appears that there are two principal stages in the development of granulations:—The first stage consists sim- ply in enlargement of the papillae from inflammatory con- gestion; the second in hypertrophy of the papillae. 495. According to the degree of development of the granu- lations, which, it is to be remarked, does not always depend on the degree of the inflammation, the surface of the palpebral conjunctiva appears, when the eyelids are everted, like red velvet—the enlarged papilla? being separated into groups by furrows or fissures; or tuberculated and sarcomatous looking like a mulberry. I have seen granulations like small pedun- culated polypi. 496. The development of a granular state of the palpebral conjunctiva is often the result of long-continued but slight con- gestion—so slight as scarcely to have attracted the patient's attention. Hence it has been maintained, that the formation of granulations takes place independently of inflammation; and when, in such cases, ophthalmia declares itself in a de- cided form, it has been alleged to be an effect or symptom of the granular state of the palpebral conjunctiva. But this is incorrect. 497. Both eyes, commonly, are affected, though one, and that the right generally, it has been said, may suffer more than the other. When both eyes become affected, there is often an interval of some days between their first invasion. 498. The lower eyelid is usually first affected, but the upper soon becomes so and suffers more than the lower—it, indeed, remains the nest of the disease. 499. Local symptoms in first and second degrees.—The first and second degrees of Egyptian ophthalmia do not essen- 8 114 EGYPTIAN OPHTHALMIA. tially differ in their symptoms, either objective or subjective, from the milder and severer forms of catarrhal ophthalmia, ex- cept in the granular state of the conjunctiva, which, though it does in some degree exist in inveterate cases of catarrhal oph- thalmia, presents itself in Epyptian ophthalmia even from the first, and remains to the last, so that it is justly considered the peculiar characteristic of the disease. 500. Constitutional symptoms in first and second degrees. —In general, there is no constitutional disturbance—no fever__ no loss of appetite. When such do occur, they depend rather on the idiosyncrasy of the patient than on the disease. 501. Objective symptoms in the third degree.—In the third degree, the eyelids, especially the upper, are very much swol- len sometimes enormously so, tense, livid, and hot. The upper eyelid hangs down over the lower. 502. If an attempt be made to open the eyelids, or even when the patient makes any effort whatever, protrusion of the conjunctiva of the palpebral sinuses, and eversion of the eye- lids, are apt to take place, in consequence of the swollen and sarcomatous state of the conjunctiva, as well as the effusion beneath it. The eversion of the eyelids is at first reducible, but by and by it may cease to be so. 503. The semilunar fold and lachrymal caruncle are so red and swollen, as to look like sarcomatous excrescences rather than natural structures. 504. The sclerotic conjunctiva, likewise red and swollen, is raised up like a wall all round the cornea, which thus appears halt buried, (chemosis.) The cornea may be as yet unaffected 505. After some hours, the secretion of the conjunctiva' which was sero-muculent, becomes muco-purulent, and is poured out in such quantity, that it is constantly flowing down the cheek. If the eyelids are suddenly opened, the matter bursts out in a torrent. 506. An oozing of blood readily takes place from the con- junctival surface. 507. The inflammation does not remain confined to the conjunctiva, but extends to the proper tunics of the eyeball the sclerotica, the cornea, and even the internal tunics. When the eyelids admit of being opened, the implication of the cornea can be seen, but that of the other parts is inferred from the sub- jective symptoms. When the eyelids cannot be opened and the cornea seen, something may be inferred as to the dear'ee to which it has suffered from the stale of the discharge if ill conditioned, there is reason to dread mischief to it ' EGYPTIAN OPHTHALMIA. 115 508. The cornea, though it sometimes escapes immediate material injury, is the part most subject to the destructive effects of the inflammation. It becomes more or less opaque from exudation into its substance. Its conjunctival layer may be- come thickened, opaque, vascular, and covered with fungous excrescences,—or phlyctenula? form, burst, and run into per- forating ulceration, which is followed by prolapsus iridis. In the worst cases, the cornea becomes wholly infiltrated with exudation, and is rapidly and completely destroyed by ulcer- ation, or by mortification and sloughing. Sometimes it bursts, but probably not before being thinned by ulceration. Even if it should have escaped these destructive effects, an ulcerated trench will probably be found, when the swelling of the parts subsides, at the place where it was pressed on by the chemosed conjunctiva. 509. Subjective symptoms in the third degree.—The se- verity of the subjective symptoms in this degree of the disease, is principally owing to implication of the proper tunics of the eyeball—the sclerotica, the cornea, and even the internal tunics. 510. There is burning hot pain in the eyelids, aggravated by the slightest touch, deep distending pain in the eyeball, and pain around the orbit, in the temple, or all over the side of the head. There is great intolerance of light, and often photopsy. 511. The pain around the orbits and in the temples occurs in nocturnal paroxysms, during one of which the cornea bursts. On the bursting of the cornea, the pain immediately remits, but returns again in another form, or passes to the opposite eye. 512. Constitutional symptoms in the third degree.—Even in the third degree, the constitutional symptoms are not severe. In some exceptional cases, indeed, before the disease has reached its greatest height, a symptomatic inflammatory fever arises, but is, notwithstanding the severity of the local affection, very moderate, and does not continue long. In the progress of the disease, however, the patient is apt to become much sunk both in strength and spirits. 513. Causes.—The cause of this disease was at one time supposed to be a peculiar contagion, first imported into Europe from Egypt (hence the epithet Egyptian) by the English and French armies. It is now, however, pretty generally conceded, that the disease does not depend upon any such peculiar con- tagion, but that it may arise from occasional atmospherical influences, sometimes sporadically, sometimes epidemically. 116 EGYPTIAN OPHTHALMIA. There are also local influences which render it endemic, in many other places besides Egypt. 514. In whatever way it arises, it may, under favouring cir- cumstances, as when large bodies of people are crowded together, become infectious. This is the explanation of its propagation in armies, schools, and prisons. 515. It has been supposed that propagation takes place principally by infection per contactum; but experience ap- pears to show, that infection in distans is the more common way,* the air being the vehicle by which the infecting principle is conveyed in the latter case, the discharge from the eye in the former. Piringert has made a number of attempts to reproduce the disease, by the application of matter from an affected eye, for the purpose of curing pannus, as will be explained in the proper place, and the results he has come to in regard to the contagion of the disease, are the following .-—The contagion is fixed, its vehicle the muciform secretion of the conjunctiva. The mucus of the second and third degree of the disease only is absolutely infectious; as the secretion becomes thinner, it loses its infectious power. Eyes which have been already diseased, appear to be less readily infected than perfectly sound GZ-ej' „ The actmty of the mucus i» not retained beyond the third day after its removal from the body; the reaction takes place in from six to twenty-four hours, usually at night The degree of the disease excited by the infection, depends on the quality of the contagion. Mucus from the first degree of the disease, or thin secretion from the second and third, occasions the first degree of the disease. Secretion from the second degree of the disease excites the third degree. The applica- tion of ice-cold water, and cleansing the eye, within three minutes after the matter has been applied, prevent the operation of the infection. , 516. Though the disease has prevailed in the most opposite climates, and in all seasons, still it appears that a very warm or a warm and damp climate or season, is peculiarly favourable to its development and propagation. 517. As causes predisposing the individual to be attacked may be mentioned fatigue, exposure, want of cleanliness, im- proper food, abuse of spirituous liquors, &c. The heavv cans and high tight collars of infantry soldiers in Prussia, Belgium dec, have been supposed by Dr. Vleminckx to be a predispos- gardf'Is?.' S°"genannte conta6iose oder Sgyptiiche Augenkrankheit. Stutt- t Die Blennorhoe am Menschenauge. Gratz, 1841. EGYPTIAN OPHTHALMIA. 117 ing cause, operating by straining the body during exercise, and impeding the free return of blood from the head. 518. Diagnosis.—It has been above shown, that the prin- cipal difference between catarrhal ophthalmia and the milder forms of Egyptian ophthalmia, consists in the great degree in which the papillary body of the palpebral conjunctiva is affected with hypertrophy in the latter,—a morbid state, which is very inveterate, and by its presence keeps up irritation and a tend- ency to relapse. 519. The severest degree of Egyptian ophthalmia is to be distinguished from the other forms of purulent ophthalmia, gonorrhoeal, for example, principally by the circumstances of the case—and by this, that in gonorrhoeal ophthalmia, the ocular conjunctiva is perhaps more swollen, the eyelids less so, and that there is an absence of phlyctenula? and granulations of the palpebral conjunctiva. 520. Prognosis in general.—When the inflammation is of an active character, and not modified by any constitutional peculiarity, early and proper treatment promises success. AVhen the inflammation is of a torpid character, and when the con- stitution is scrofulous, it less readily yields to treatment, subsides less quickly and perfectly, and fixing itself in the structures of the eye, is apt to produce degeneration of it. In erethitic irritable cases, the prognosis is also unfavourable, but less so than in torpid cases. 521. Sporadic cases are usually of middling severity. In an epidemic, the disease is at first mild, then increases in severity, and again becomes milder towards the end. When the disease is endemic, the cases, without being of the severest character, are in general very inveterate, if neglected. 522. The disease arising from contagion is more dangerous than when otherwise produced. 523. Prognosis in the first degree.—The disease in the first degree, especially if properly and timely treated, may in general be readily subdued. If not timely and properly treated, the disease may pass at once into the severer degree, or fall into a chronic state. In this state, however, it is still ready, on the application of any exciting cause, to rise into the severer de- gree. 524. Prognosis in the second degree.—The disease in the second degree, if taken in time and properly treated, may still be cured in three or four weeks. But if the inflammation has already been going on for a week or so, even if the cornea is still unaffected, though the inflammation may be readily re- 118 EGYPTIAN OPHTHALMIA. moved from the sclerotic conjunctiva, the palpebral conjunctiva will remain long in a thickened and granulated state. 525. When the disease has become fully developed before medical assistance is called for, vascularization and ulceration of the cornea may have taken place. This affection of the cornea is kept up, if not aggravated, by the morbid state of the palpebral conjunctiva; hence the prognosis is very unfavourable, as opacity and permanent vascularity of the cornea may result. The ulceration may penetrate the cornea. 526.—Prognosis in the third degree.—In the third degree of the disease, a perfect cure is seldom effected. If the eye is not disorganized, which it may be in 24—36 hours, by destruction of the cornea, it may be very much injured by perforating ulcera- tion and its consequences. Besides this, the morbid state in which the conjunctiva is left is long of being recovered from, perhaps never perfectly, and is a constant source of irritation. 527. Treatment.—In the first degree, leeches around the eye, and opening medicine, are to be first prescribed. Then lotions of tepid water, or the constant application of cold, and pencil- ing the palpebral conjunctiva once a day with the nitrate of silver drops, (s. 128,) or with the strong red precipitate oint- ment (s. 136). 528. In the severer degrees of the disease, if the patient be of good strength, venesection to gxij—xvj—xx, followed at bed-time with Dover's powder, gr. x—xx, and calomel, gr. iij—v, and a black draught next morning. In some cases, leeches around the eye may be required to follow up the vene- section, or it may be necessary to repeat the latter. 529. After the bleeding, &c, the application to the conjunc- tiva of strong irritants should be made, as nitrate of silver in substance, salve, or solution, or the strong red precipitate salve once or twice a day, and the eye bathed and cleansed frequently with tepid water, or the tepid solution of alum, or of bichloride of mercury, (s. 124.) 530. If chemosis exists, and if the cornea appear much buried and pressed on by it, incision, or excision of small pieces of the chemosed ocular conjunctiva ought to be had recourse to with- out delay, (ss. 152, 443.) Incision or excision of the che- mosed conjunctiva relieves the eyeball, and especially the cornea, from the pressure which is considered, as above men- tioned, (s. 357,) to be one great cause of its destruction. 531. When the iris and other internal structures of the eye- ball become affected, as is indicated by change of colour of iris and contraction of pupil, provided these can be seen, and by OPHTHALMIA OF NEW-BORN INFANTS. 119 pulsative pain in and around the eye, with inflammatory fever, the propriety of abstraction of blood, either by venesection, cupping or leeches, will again come under consideration. It will, in any case, be proper to give calomel, gr. ij and opium, gr. ss every four hours, until the gums are affected, and to apply belladonna around the eye. 532. When the violence of the inflammation has subsided, it will be advantageous to improve the diet and give tonics,— quinine or bark, especially if there be periodical pains in or around the eye. Also to make counter-irritation behind the ears or on the nape of the neck. 533. The special treatment of granular conjunctiva, of pan- nus, of ulceration of the cornea, prolapsus iridis, &c, which may present themselves as the effects of the inflammation, will be treated of under the proper heads. Ophthalmia of new-born infants. (Ophthalmia neonatorum—Purulent ophthalmia of infants.) 534. It is generally within a week after birth that this ophthalmia makes its attack. Sometimes it is observed im- mediately after birth, sometimes, again, as late as three or four weeks. 535. Objective symptoms.—It is first noticed, that the infant keeps the eyes shut, that the edges of the eyelids are slightly- redematous and red, and that they are glued together after sleep with an inspissated yellow matter, which is the Meibomian se- cretion increased in quantity. On softening this, and separating and everting the eyelids for examination, the palpebral con- junctiva is found red and spongy; and sclerotic conjunctiva but little injected. 536. In this way, first one eye, and in a day or two the other becomes affected. That first affected generally suffers most in the course of the disease. 537. The swelling and redness, which were at first confined to the edges, by and by extend to the whole eyelids, especially the upper. The palpebral conjunctiva becomes still more red, swollen, and velvety. The lachrymal caruncle and semilunar fold are red and swollen, and the sclerotic conjunctiva is now more or less injected, even to the margin of the cornea. A whitish sero-muculent discharge is at the same time established. This will perhaps flow out in some quantity when the eye is opened for examination, having been pent up and accumulated in the conjunctival space, in consequence of the gluing together of the edges of the eyelids. 120 OPHTHALMIA OF NEW-BORN INFANTS. 538. As the disease approaches its height, the swelling of the eyelids increases, and their skin becomes of a brownish-red colour, tense, and shining. The upper eyelid, which is always the more swollen, overlaps the edge of the lower. 539. On separating the eyelids, a quantity of thick puriform matter escapes, and the eyelids perhaps become everted, and the conjunctiva of the palpebral sinuses protrudes, so great is the swelling of the conjunctiva. Eversion of the eyelids, and protrusion of the conjunctiva of the palpebral sinuses, may take place even by the contraction of the muscles when the infant cries. The lachrymal caruncle and semilunar fold are very much swollen, and the sclerotic conjunctiva is in the state of chemosis. In this stage of the inflammation, discharge of blood readily takes place from the conjunctival surface. 540. Hitherto the cornea may have continued unaffected, or at the most may have been hazy; but chemosis has usually not existed long, before it suffers more or less injury, becoming the seat of ulceration, abscess, or destructive purulent infiltration. When such mischief as this occurs, the discharge becomes ichorous, and a diminution of the swelling and tension of the eyelids takes place. 541. Constitutional symptoms.—As the disease proceeds, the infant becomes fretful and uneasy, does not suck, nor sleep, and its mouth becomes aphthous. 542. Causes.—The infants, the subjects of this ophthalmia, are generally weakly, often twins, or prematurely born. 543. Sometimes the disease can be attributed to no other ex- citing cause than such as gives rise to catarrhal ophthalmia. In many cases, exposure of the eyes to heat and light, or the direct intrusion of irritants, such as the soap or spirits used in washing, the infant, appears to be the exciting cause. Inocula- tion with leucorrhceal matter from the vagina of the mother during parturition, there is reason to believe is a very common cause. Inoculation with gonorrhoeal matter is, for obvious reasons, a less frequent cause. Dr. Cederschjold of Stockholm, found ophthalmia neonatorum occur in 20 out of 137, or 1 in 7 infants the mothers of whom were affected with vaginal dis- charge; and in 10 out of 181, or 1 in 18, the mothers of whom were not so affected. 544. The disease may be propagated by infection per con- tactum. Adults having had the discharge from the infant's eyes accidentally applied to theirs, purulent ophthalmia has been pro- duced, and that so severe as to destroy the eyes. 545. When there is a number of infants labouring under this OPHTHALMIA OF NEW-BORN INFANTS. 121 disease collected together, as in lying-in and foundling hospitals, infection appears to be propagated in distans. 546. Prognosis, and course.—In whatever stage of the dis- ease the medical man be called in, he may in general pronounce a favourable prognosis, if he finds the cornea still clear, or even though hazy, still free from ulceration or abscess. If ulceration or abscess have taken place, the extent to which the cornea will be preserved clear, whether it may not be perforated and pro- lapsus iridis take place, and this whether to the extent of con- stituting the condition for the formation of partial staphyloma, can only be doubtfully prognosticated until a decided stop is put to the inflammation. The prognosis may then be regu- lated by the degree and extent to which the cornea has suffered, (ss. 359-363.) If the cornea have become completely infil- trated with matter, it is destroyed; it will be thrown off by ulceration or sloughing, the iris will protrude, and the condition be laid for a total staphyloma. 547. Though the eye may have otherwise escaped, it may be left affected with central capsular cataract, strabismus, or incomplete amaurosis. 548. The disease yielding, the swelling of the eyelids di- minishes. From being tense and shining red, the skin becomes wrinkled and pale livid. The chemosis and redness of the sclerotic conjunctiva subside; but although the swelling of the palpebral conjunctiva becomes much diminished, its redness and the enlarged state of its papillae more slowly disappear. The purulent discharge becomes less and less. All this, and the course to a cure, proceed rapidly if the cornea have remained unaffected; but the existence of ulceration, <__c, of the cornea necessarily retards the cure of the other parts, which, in fact, proceeds only in proportion as the cornea heals. 549. Treatment.—The disease may be successively treated from the first by such applications as nitrate of silver drops or ointment, or strong red precipitate ointment, (ss. 128, 126.) These remedies must be applied by the surgeon himself once a day. Before the application, the eye is to be cleansed from discharge. 550. The nurse should use the alum, or bichloride of mercury collyrium tepid, three times a day, for bathing and cleansing the eye; and the weak red or white precipitate ointment, for anointing the edges of the eyelids, to prevent them from being glued together. 551. If the disease has come to a height before the surgeon is called in, it will often be necessary to have recourse, in the 122 GONORRHEAL OPHTHALMIA. first place, to the application of a leech to the swollen upper eyelid, or what is better, perhaps, to scarification of the red, swollen, and spongy palpebral conjunctiva before applying the strong drops or ointment. The scarification of the palpebral conjunctiva maybe required to be repeated more than once; and if the chemosis be great, and the cornea much buried and becoming dim, it will be advisable to make some deep scarifi- cations in the chemosed sclerotic conjunctiva also. 552. Small blisters behind the ear in severe cases promote the action of the preceding treatment. 553. Internally, a little castor-oil, or rhubarb and magnesia, is to be given as occasion requires; and when the cornea is threatened, small doses of calomel and quina, gr. ^ of the former, and gr. ss of the latter, rubbed up with sugar twice a day. 554. The diet of the nurse is to be carefully regulated. Dur- ing the height of the disease, she should abstain from animal food and strong drinks. 555. When the puriform discharge has ceased, but the con- junctiva remains relaxed, drops of vinum opii, diluted with an equal part of water, or the lapis divinus drops, (s. 128,) are to be applied to the conjunctiva once a day, or once every second day; and the nurse may now take besides animal food and wine or porter, tincture of iron. 556. Whenever the eyelids become everted, they should be immediately restored to their proper position, which is done by seizing the eyelid between the finger and thumb, drawing it a little from the eyeball, and then turning it down. Should the eversion have been allowed to continue some time, and the eye- lid cannot be restored to its proper position, the everted con- junctiva is to be scarified; and when it has thus been somewhat emptied of blood, it will admit of being returned more readily. Gonorrhoeal ophthalmia. (Ophthalmia gonorrhoica vera—Acute gonorrhoeal inflammation of the con- junctiva.) 557. Diagnosis.—This ophthalmia resembles very much the severest form of Egyptian ophthalmia. If there is any differ- ence, it is this:—In gonorrhoeal ophthalmia, the sclerotic con- junctiva is affected from the very first, and great and inveterate chemosis rapidly forms ; whereas in Egyptian ophthalmia, the sclerotic conjunctiva becomes affected subsequently to the pal- pebral conjunctiva, the chemosis does not form so rapidly, nor is it so inveterate. In gonorrhoeal ophthalmia, though' the inflammation of the palpebral conjunctiva and swelling of the MILn GONORRHEAL OPHTHALMIA. 123 eyelids may be very great, it is in general not so considerable as in Egyptian ophthalmia; and, at any rate, the papillae of the palpebral conjunctiva do not become affected in the same way; hence granulated conjunctiva does not occur in, or is not so marked a result of gonorrhoeal as of Egyptian ophthalmia. 558. In consequence of the greater severity of the inflam- mation of the sclerotic conjunctiva, the cornea is still more liable to suffer and be destroyed in gonorrhoeal than in Egyptian ophthalmia. Indeed, gonorrhoeal ophthalmia is the most rapidly destructive disease the eye is subject to. 559. Males are oftener affected with this disease than females; but it is of comparatively rare occurrence in either sex. 560. In general one eye only is affected in gonorrhoeal oph- thalmia ; whereas in Egyptian ophthalmia, it is extremely rare to meet with a ease in which the disease remains confined to one eye. 561. The differences, it will be observed, are not sufficiently strict to serve as a practical ground of diagnosis. The history of the disease forms the best ground of diagnosis. 562. Cause.—Inoculation with gonorrhoeal matter. 563. Prognosis.—Until, with a cornea safe, or at least not much ulcerated, the disease is on the decline, which is known by the subsidence of the swelling of the eyelids and of the che- mosis, with diminution of the discharge, the prognosis must be extremely unfavourable. The eye may be destroyed in forty- eight hours from the commencement of the disease. 564. Treatment.—The treatment must be the same as in the severest form of Egyptian ophthalmia, only, if possible, more active. No delay of treatment can be admitted. Incision or excision of the chemosed conjunctiva should be early had recourse to, and counter-irritation by blisters to the nape of the neck, behind the ear, or even on the eyelids themselves. Mild gonorrhceal ophthalmia. 565. A milder form of ophthalmia is met with in persons labouring under gonorrhoea, which, however, does not appear to differ from common catarrhal ophthalmia. The cases of the kind which I have seen have not appeared to me in any other way dependent on gonorrhoea, than thatat the time the system was in consequence of it more susceptible to cold. The expo- sure to which, at the same time that it excited the ophthalmia, operated in checking the discharge from the urethra.* They * Iritis in connection with gonorrhoea, will be considered farther on, under the head of Iritis. 124 ERYSIPELATOUS OPHTHALMIA. readily yielded to the same treatment as is above indicated for catarrhal ophthalmia. Puro-mucous ophthalmia occurring in female children, in connection with puro-mucous discharge from the vagina. 566. This ophthalmia, though sometimes severe, is usually of a mild character. 567. Symptoms.—In a case of two or three days standing, the eyelids were red and swollen, but not tense, and. admitted of being readily opened. The conjunctiva was red but not intensely so—the palpebral conjunctiva spongy—the sclerotic conjunctiva raised up over the lower margin of the cornea in a state of slight chemosis. The cornea was still quite clear. There was a serous discharge, mixed with considerable flakes of thick whitish yellow matter. No pain, and little or no in- tolerance of light. 568. Treatment.—Scarification of the palpebral conjunc- tiva—the nitrate of silver drops once a day—the alum lotion two or three times a day for cleansing the eye—the red pre- cipitate ointment at bed-time and some laxative medicine— checked the inflammation in a few days. The healing process was then promoted by a blister behind the ear, penciling the conjunctiva with lapis divinus drops, and the exhibition of quina. 569. When the chemosis subsided, superficial ulcer of the cornea was discovered where it had been pressed on by the fold of conjunctiva. This readily healed, leaving a slight opacity, but was the cause of retarding somewhat the recovery. 570. The vaginal discharge subsided under the use of a sul- phate of zinc injection. Erysipelatous ophthalmia. (Conjunctivitis erysipelatosa idiopathica.) 571. The conjunctiva is always more or less affected in ery- sipelas of the eyelids, but idiopathic erysipelatous ophthalmia is not of frequent occurrence. 572. Objective symptoms.—To the anatomical description of erysipelatous inflammation of the conjunctiva above given, it only remains to add under this head, that in consequence of the gravitation of the fluid, the serous chemosis is greater below than above—that the cornea appears half buried by jt__ that there are occasional lachrymation and increased Meibomian secretion. 573. Subjective symptoms.—-There is an uneasy sensation PUSTULAR OR APHTHOUS OPHTHALMIA. 125 of pressure and tension about the eye when it is moved, with itching and smarting pain, and some impatience of light. 574. Constitutional symptoms.—The subjects of this oph- thalmia are most commonly persons of weakly constitution, advanced in life, or labouring under gastric derangement: but these conditions are to be viewed rather as the predisposing causes than as the symptoms of the ophthalmia. 575. Causes.—The predisposing causes have been just re- ferred to.—Exciting causes. Exposure to cold and wet. In- juries, chemical or mechanical, of the conjunctiva; it sometimes occurs after needle operations for cataract. In an old man affected with small irritable ulcers on his legs, with surrounding erythema, I once saw it occur as if by metastasis on the appli- cation of warm fomentations to the legs. 576. Diagnosis.—The nature of the conjunctival inflamma- tion is at once perceived; but in forming the diagnosis, it should be determined whether there be any complication—such as sclerotitis. 577. Prognosis and course.—The prognosis is good. The disease usually begins to subside in a few days—the watery effusion is gradually absorbed—and the conjunctiva becomes again applied to the sclerotica, but continues for some time in a loose flaccid state. During this process, the injection of the conjunctiva disappears, but the spots of extravasated blood are some time of being absorbed. The lachrymal, Meibomian, and conjunctival secretions return to their natural quantity and quality. 578. Treatment.—Three grains of mercurial chalk, with watery extract of aloes, and extract of hyoscyamus, of each one grain at bed-time, followed by a purgative draught in the morn- ing ; and as a collyrium, the solution of the bichloride of mer- cury, with vinum opii, (s. 124,) will in general suffice to check the disease. Good diet, cordials, and tonics, may be afterwards given. 579. Instead of a lotion, some prefer dry warmth, by means of medicated bags, (s. 116,) hung over the eye. If more agree- able to the patient, this may be adopted; but in either case it will be necessary afterwards to drop in vinum opii to give tone to the relaxed membrane. Pustular or aphthous ophthalmia. (Aphthous inflammation of the conjunctiva.) 580. This name is confined to the case in which the pus- tules or aphthae are situated on the sclerotic conjunctiva—a 126 PUSTULAR OR APHTHOUS OPHTHALMIA. tenth or a twentieth of an inch from the margin of the cornea, or close to the margin of the cornea, but not on the cornea. 581. Objective symptoms.—To the objective description of pustular inflammation of the conjunctiva above given, (ss. 314-318,) all that requires to be added here, is that the cornea is quite clear—that there is no decided lachrymation, though a flow of tears is readily excited by the movements of the eye— and that there is an increased Meibomian discharge, sufficient, perhaps, to cause gluing together of the eyelashes over night. 582. Subjective symptoms.—There is not the slightest in- tolerance of light, or perhaps any other local inconvenience, except a sensation like that from a foreign body in the eye, which is excited by the pustule and its enlarged vessels. It is not, however, distressing, in consequence of the general sensi- bility of the conjunctiva not being exalted. 583. Constitutional symptoms.—There is little or no con- stitutional disturbance. 584. When pustules present themselves close to the margin of the cornea, (s. 317,) the subjective symptoms may be as slight as above described; but the case in which this occurs is apt to pass into, if it is not already, one of scrofulo-catarrhal, or of phlyctenular corneitis, or common scrofulous ophthalmia, which is attended with great intolerance of light and lachry- mation. 585. Causes.—-Pustular ophthalmia occurs in children and young adults, especially females. It is usually excited by ex- posure of the eye to a draught of air. In a little boy, for ex- ample, it was brought on by looking through the keyhole of a door and receiving on the eye the current of air passing through. 586. Diagnosis and prognosis.—Practically, it is of im- portance not to confound pustular ophthalmia with phlyctenu- lar. In the former, the application, two or three times repeated, of nitrate of silver drops, or strong red precipitate ointment, will seldom fail to cure; whereas in the latter, the curability is entirely different. Seeing that when the pustules are at the margin of the cornea, the case is apt to be mixed up with phlyctenular ophthalmia, the curability is under such circum- stances modified. The combination with catarrhal or scrofulo- catarrhal ophthalmia, has not so great a modifying influence. 587. Treatment.—Any application, such as the nitrate of silver drops, (s. 128,) or salve, or red precipitate salve, (s. 136,) een above pointed out, (s. 9.) ) be noticed are those which AMAUROSIS AND GLAUCOMA. 9. The eyeball may be either preternaturally hard to the touch, or preternaturally soft. 10. In amaurosis there is often an appearance as if of opacity behind the pupil; in glaucomatous amaurosis, it is a constant and well-marked appearance. In simple amau- rosis it is pale,* in glaucoma it is greenish. 11. In amaurosis and glau- coma, the appearance of opa- city is evidently deeper seated, but where it is seated one can- not, by merely looking into the eye, say exactly, especially as it appears to change place ac- cording to the direction in which light is admitted to the eye. It is seen most distinctly when we look direct into the eye—indistinctly, or not at all, when we look sideways from the side opposite the light. It is most distinct in the ordinary state of the pupil, but when the pupil is dilated, it is scarcely or not at all to be seen. 12. The pupil and its move- ments not in general natural; * A similar appearance may often be observed in old people unaffected with amaurosis. HARD LENTICULAR CATARACT. 231 CATARACT. AMAUROSIS AND GLAUCOMA. Readily and quickly yields to the pupil is more or less di- the influence of belladonna. lated, and if not quite immov- able, its movements are limited and slow. Yields slowly and imperfectly to the influence of belladonna, if not already quite dilated. 13. In amaurosis, uncom- bined with glaucoma, the three images are always distinct. Glaucoma only when much advanced, obliterates the in- verted image, while in all its stages, it renders the deep erect one more evident than it is in the healthy eye. 14. In glaucoma at a mid- dle stage, the inverted image is pretty distinct when formed near the edge of the crystaline; but if the candle be brought in front of the eye, the inverted image is less distinct, and in some cases is altogether ex- tinguished. This extinction of the inverted image, when the candle is brought in front of the eye and not otherwise, is owing to a loss of trans- parency in the kernel of the lens, while the superficial strata are still transparent. 1241. Prognosis and treatment.—When once begun to form, it may be prognosticated that the opacity will go on to increase until all useful vision is prevented in the eye. And it may also be prognosticated, that the other eye will likewise become affected. How quick or how slow the progress to loss of useful vision, however, may be, cannot be prognosticated— it may be months or it may be years. 1242. Restoration of vision can be effected only by an ope- ration, by which the opaque lens shall be removed from its situation—pressed down below the level of the pupil, (the ope- 13. In cataract, even in an early stage, the inverted image is obscure, or obliterated, and the deep erect one very indis- tinct. 14. The inverted image,long before the cataract is fully formed, is not produced, or but indistinctly, whether the candle be held opposite the central or the circumferential part of the lens, owing to the circumstance, that it is the superficial strata of the lens which are first affected, and which of course prevent the distinct formation of the in- verted image, as well by the middle as by the circumferen- tial part of the lens. 232 SOFT LENTICULAR CATARACT. ration of displacement,) or extracted from the eye altogether— (the operation of extraction.) Soft or common lenticular cataract of young people. 1243. The cataract is of the same consistence as that which is natural to the lens, or softer, and of a grayish-white, or milk and water opacity throughout its whole substance. It presents, in the earlier stages of its opacity, the glistening tendinous as- pect and stellate appearance above described; in short, the soft cataractous lens at first very closely resembles a healthy lens, rendered opaque and swollen by the action of reagents. But by and by it may come to have less of the appearance of the original structure, looking like broken spermaceti or white sugar. The lens is generally of the natural size, but is some- times larger. 1244. Subjective symptoms.—Vision is diminished in pro- portion to the opacity, in a manner analogous to what is above described to be the case in hard cataract. 1245. Objective symptoms.—These are, on the whole, much the same as those of hard cataract above described, with the exception of what differences are produced by the differences in colour, general aspect of the opacity, and size of the cataract- ous lens. 1246. The iris and pupil may be natural, but according to the size of the lens, so will be its closeness to the iris and the breadth of the shadow. If, as is often the case, it is so large as to press on the iris, the motions of the pupil are impeded, and the shadow is altogether wanting. 1247. Causes.—The occurrence of opacity of the lens in young persons, is very much rarer than in old persons. It is often met with as the result of injury. In children affected with lenticular cataract, we are sometimes told that the opacity made its appearance after convulsions. In other cases it cannot be traced to any cause. 1248. Diagnosis.—There is less likelihood of this form of lenticular cataract being confounded with amaurosis than the preceding—none at all with glaucoma, as this does not occur except in old persons. It is to be remembered, however, that this form of cataract is not unfrequently complicated with amau- rosis. Soft lenticular cataract being whiter than hard, is less readily distinguished from capsular cataract. 1249. Prognosis and treatment.—What is above said on these heads (s. 1241), in regard to hard cataract, is in general applicable here, except that the kind of operation best adapted ANTERIOR CAPSULAR CATARACT. 233 for the removal of the opaque lens, is that by division, in order to its solution and absorption. II.--CAPSULAR CATARACT. 1250. The anterior and posterior walls of the capsule may be separately affected with opacity. Hence are recognized anterior capsular cataract, and posterior capsular cataract. Opacity of the lens is apt to supervene, so that the case merges into cap- sulo-lenticular cataract. Opacity of the lens more speedily supervenes on posterior capsular cataract than on anterior. Occasionally both the anterior and posterior walls of the capsule are the seat of partial opacity, the lens remaining transparent. Anterior capsular cataract. 1251. The opacity in anterior capsular cataract has more analogy with opacity of the cornea than opacity of the lens. It is usually dead white, and either implicates the whole ante- rior wall of the capsule, or perhaps one half, or occurs in ab- ruptly defined patches, spots or streaks quite irregular both in form and disposition, except in the case of central capsular cataract, in which the opacity occurs in the form of a single elevated opaque spot, seated in the centre of the capsule. This elevated opaque spot is sometimes of a pyramidal shape, its apex projecting towards the pupil. 1252. According to the differences in the general aspect of the anterior capsular cataract, produced by the differences in the disposition of the opacities, such names as the following have been given to the cataract: cataracta capsularis anterior tota- lis, dimidiata, centralis, marmoracea, striata, fyc. 1253. Motions of the pupil.—The motions of the pupil may be natural, but very often they are impeded by adhesions be- tween the pupillary margin of the iris and the capsule of the lens. 1254. Subjective symptoms.—According to the situation and extent of the specks, so the loss of sight may be greater or less than in lenticular cataract. Complications often exist which may disturb the vision more than the mere capsular opacity. 1255. Causes.—Anterior capsular cataract appears generally to be the result of inflammation of the eye, ophthalmia neona- torum, or scrofulous ophthalmia, for example, more frequently than iritis. . _•_•_■_ 1256. The diagnosis of anterior capsuiar cataract is founded principally on the superficial seat and whiteness of the opacity, and its speckled disposition. 234 CAPSULO-LENTICULAR CATARACT. 1257. Prognosis and treatment.—Anterior capsular cataract is like opacity of the cornea, not prone to extend, the inflam- mation which originally gave rise to it having ceased, and it may continue for many years, or for life, without the supervention of lenticular opacity. Not unfrequently so much vision is still preserved, that no interference in the way of operation is re- quired. Any operation that may be undertaken, must be the same as for capsulo-lenticular cataract, for the capsule cannot be removed without sacrificing the lens. Posterior capsular cataract. 1258. Simple uncombined opacity of the posterior wall of the capsule is rare, for it is soon followed by lenticular opacity. Little, therefore, is known of its appearances. Opacity of the posterior strata of the lens has been sometimes mistaken for it. Dr. Mackenzie, who has had frequent opportunities of examin- ing posterior capsular cataract, describes its appearances:— The opacity, in posterior capsular cataract, is never uniformly diffused, but always exhibits the form of radiating lines, proceed- ing from the centre of the affected membrane. The ground upon which these opaque lines are placed, is evidently concave and deep-seated, while the lines themselves, being seen through the crystaline, have a watery dullness of appearance, which forms a striking contrast to the sharp chalky whiteness of the specks in anterior capsular cataract. 1259. Posterior capsular cataract of itself has no more influ- ence on the motions of the pupil than other kinds of cataracj. Being liable, however, to be complicated with amaurosis, it may be attended by a dilated and fixed pupil. 1260. Vision is impaired in very various degrees—the patient being able in some cases to read by the aid of a magnifying glass ; while in others he is almost blind. 1261. Prognosis and treatment.—As above said, posterior capsular is soon followed by lenticular opacity, and the case thus becomes one of capsulo-lenticular cataract, so that the treatment must be the same as for capsulo-lenticular cataract; but the prognosis is in general unfavourable, in consequence of the liability of this species of capsular cataract to be complicated with amaurosis. III.--CAPSULO-LENTICULAR CATARACT. 1262. In capsulo-lenticular cataract, the opacity may be par- tial or complete. It may be confined to a small spot on the COMMON CAPSULO-LENTICULAR CATARACT. middle of the anterior capsule, and of the lens, the rest of the body being healthy; or the opacity may be to a greater extent, andj»the lens hard, soft, or in a more or less fluid state. The opacity of the anterior capsule, which varies in degree as in simple anterior capsular cataract, may be combined with thick- ening of it. 1263. Sensibility to light is occasionally very feeble in cap- sulo-lenticular cataract, owing in some cases to the density of the opacity, in others to the presence of amaurosis. Cataract supervening to amaurosis, and especially to traumatic amau- rosis, is frequently capsulo-lenticular. The cataract is slow in its progress under such circumstances. At length the vitreous humour dissolves, and the iris and cataract become tremulous. 1264. According to the differences above enumerated, differ- ent species of capsulo-lenticular cataract are recognized. Central capsulo-lenticular cataract. 1265. This seems to belong to the same head as central capsular cataract, from which it differs merely in presenting a circumscribed opacity of the lens at the place corresponding to the opacity of the capsule. Both species occur congenitally, or make their appearance shortly after birth—often after oph- thalmia neonatorum. The lenticular opacity may be broader, but is not in general so dense as the capsular. Central cataract is rarely capsular merely, it is in general capsulo-lenticular. It often co-exists with congenital defects. I have met with it along with night blindness. 1266. The effect of central capsulo-lenticular cataract on vision is short-sightedness. 1267 Treatment.—-No operation is called for. It the pupil is not habitually dilated so as to expose the clear part of the crystaline for the passage of light, the drops of belladonna or atropia are to be used for that purpose, (s. 128.) Common capsulo-lenticular cataract. 1268 The appearances are those principally of anterior cap- sular cataract, when the opacity of the anterior capsule is com- plete When the opacity is incomplete, the opacity of the lens is seen through the transparent places. The lens may be hard, soft or fluid. . r _.-_ 1269 When dissolved, the lens forms an opaque white or vellowish fluid, which distends the cataractous capsule. In some cases, the opacity and fluidity of the lens precede the opacity of the capsule; while in other cases the diseased state 236 CYSTIC CAPSULO-LENTICULAR CATARACT. of the capsule appears to lead to the disorganization and disso- lution of the lens. The latter is probably the case in ordinary cases of capsulo-lenticular cataract, while in congenital cata- ract, which is generally capsulo-lenticular, when it comes under notice, the opacity of the capsule is certainly preceded by that of the lens.* 1270. What has been called Morgagnian cataract appears to be an early stage of fluid cataract, and to consist in softening and opacity of the exterior part of the lens, with perhaps ab- sorption by endosmose of aqueous humour into the capsule, determined by the diseased state of the lens, similar to what takes place after death, and which is the true source of what is called the Morgagnian fluid. 1271. In fluid cataract, the capsule may be seen, when the pupil is dilated, bulged forwards at the lowest part by the sub- sidence of the opaque fluid. In this state, the opacity is, of course, greater below than above. 1272. The iris being more or less pressed upon by the cap- sule, distended with the fluid lens, the movements of the pupil are impeded. The iris may be pressed forward towards the cornea. Siliquose capsulo-lenticular cataract, or membranous cataract. 1273. This results from the more or less complete absorp- tion of the lens, and collapse and thickening of the opaque capsule. It is of a grayish-yellow colour, and softish, easily broken up, in young persons: whiter, firmer, and tougher in grown-up persons. It is sometimes so much shrunk in diame- ter, that when the pupil is dilated, the zonula lucida appears around it, and radiating white bands are seen extending from it to the ciliary body, (cataracta cum zonula.) It is also so much shrunk in thickness, that it is evidently at a considerable distance behind the iris, which may, in consequence, be in- clined backwards. 1274. Of course the movements of the pupil cannot be in- fluenced by the cataract, but they may be so by concomitant complications. Cystic capsulo-lenticular cataract. 1275. In this species the lens is fluid, and the capsule opaque and distended with it, so that the crystaline body is globular and enlarged, pressing forward the iris. When the vitreous body is at the same time dissolved, the cataract pre- * Mackenzie's Practical Treatise. Third Edition, p. 657. OPERATIONS FOR CATARACT. 237 sents tremulous movements with every turn of the eye or head, (cataracta cystica tremulans vet natatalis.) Being no longer fixed, it falls down below the pupil, and is apt to pass through it into the anterior chamber. 1276. Cystic capsulo-lenticular cataract is almost always complicated with amaurosis, and is generally the result of a blow on the eye or its neighbourhood. B. THE OPERATIONS FOR CATARACT. 1277. The restoration of vision in cataract cannot be effected by any means except by operation. The different operations for this purpose have for their common object the removal of the opaque lens, or of both it and its capsule from behind the pupil, so that the rays of light may be again allowed to pass on to the retina. This object is sought to be effected in one or other of three different ways, according to the circumstances of the case, viz.—1st. By at once extracting the cataract from the eye. 2d. By simply displacing it to below the level of the pupil. 3d. By lacerating the capsule and dividing the lens, in order that the latter, being exposed to the action of the aqueous humour, may be gradually dissolved and absorbed, and thus eventually removed altogether from the eye. Of these three different ways, again, there are different modifications. General observations and questions regarding the operations for cataract. 1278. Prognosis of the operations for cataract in general. __The success of operations for cataract depends very much on the kind of cataract, the age of the patient, and the local and constitutional complications; but, as a general estimate, it may be admitted with Dr. Mackenzie, that three-fourths of patients operated on recover useful vision, and two-thirds excellent vision, when such cases only as are fitted for operation are operated on; when the mode of operating is adapted to the particular case; when the operation is well performed, and the after-treatment skillfully conducted. 1279. Kind of cataract.—-The prognosis in lenticular cata- ract is much more favourable than in capsular. As to hard and soft lenticular cataract, the prognosis in them merges into that of extraction and division. 1280. Age of the patient.—The prognosis is better m young children and old persons than in persons in the prime of life; but this is mainly because it is in early life and old age that 238 OPERATIONS FOR CATARACT. the cataracts most favourable for operation occur. The general complications connected with age which are unfavourable to the success of operations for cataract, are, in early life, scrofula, and in advanced life, gout. 1281. Complications of cataract.—Before an operation for cataract is determined on, it is necessary to examine not only the state of the eye in other respects, but the state of the sys- tem in general, lest complications should exist which might interfere with the success of the operation. This they might do in two ways, viz., either by interfering with its success as an operation simply, or the operation as an operation being suc- cessful, by interfering with the accomplishment of its ultimate object of restoring vision. 1282. The complications which might interfere with the success of the operation as an operation, i. e., the successful removal of the cataract, without subsequent injury to the eye from undue inflammation or the like, may be either local, such as entropium, ectropium, trichiasis, ophthalmia tarsi, chronic ophthalmia, or the like; or constitutional, such as disposition to erysipelatous and catarrhal inflammations, scrofula, syphilis, gout, scurvy, chronic diseases of the skin, habitual ulcers of the legs, nervous complaints. 1283. In regard to local complications it is to be observed, that there are certain morbid states of the eye, which, though they might seriously interfere with the success of an operation as an operation, performed in one way, would be little or no impediment to the success of an operation performed in another way; thus, whilst synechia anterior, contracted pupil, or dis- solution of the vitreous body, would be incompatible with the success of the operation of extraction, they would offer little or no impediment to the success of displacement or division. 1284. The operation as an operation being successful, the complications which might interfere with the accomplishment of its ultimate object of restoring vision, are local, such as de- fective sensibility of the retina, extensive opacity of the cornea. 1285. Of the different kinds of complications of cataract above enumerated, most admit of cure, or of such palliation as is calculated to remove or diminish the risk of their interfering to prevent the success of an operation. Defective sensibility, or total insensibility of the retina, however, in general admits of no cure, and is therefore, of course, a complication rendering all operative interference fruitless. 1286. The diagnosis of the various complications of cata- ract above referred to, is either quite evident, or not obscured OPERATIONS FOR CATARACT. 239 by the presence of the cataract; but it is different in the case of complication of cataract, with defective sensibility of the retina; for without a careful consideration of all the circum- stances of the case, including an inquiry whether, at the com- mencement, the loss of vision was accompanied by any symp- toms of posterior internal ophthalmia, (s. 860,) and an exami- nation of the eye, with the pupil under the influence of belladonna, the defect of vision might be attributed solely to cataract, especially as ready perception of light and shade still remains. In the case of total insensibility of the retina, the diagnosis is in general easy, seeing that cataract never produces complete blindness (s. 1239). 1287. When one eye only is affected with cataract, and the vision of the other good, should an operation be performed ?— Under such circumstances, the practitioner will not recommend recourse to an operation, and indeed the patient is not likely to desire it, except, as is sometimes the case with young persons, generally females, when the cataract is white and very evident, for the sake of getting rid of the deformity. 1288. When in one eye useful vision is lost, and in the other, vision has become misty from cataract, should an opera- tion be performed on the former?—The usual advice is to wait until useful vision is lost in the latter also; but it is better to operate at once on the blind eye, though the determination of the point may be left to the convenience of the patient. 1289. When in an elderly person double lenticular cataract has become so far developed as to interfere with useful vision, when should an operation be had recourse to?—If extraction is to be performed, operate as soon as possible, for there is more chance of the vitreous body being sound than at a later period- if, on the contrary, displacement is to be performed, the operation maybe deferred until the cataracts be more developed. 1290 When cataract is fully formed in both eyes, may both be operated on at the same time?—As a general rule, the an- swer is in the negative, if extraction is to be performed; m the affirmative, if displacement or division. 1291 In cases of congenital cataract, at what age should the operation be performed ?-It ought to be performed in in- fancy, and, if possible,before teething commences; if not, soon after teething is completed. . 1292. Preparation of the patient for undergoing an opera- tion for cataract.—If the case be free from local or constitu- tional complications, the patient requires no other preparation 240 OPERATIONS FOR CATARACT. than a few days' rest of mind and body, some attention to diet, and to the state of the bowels. If, on the contrary, any such complications exist, he ought, before the operation is under- taken, to be subjected to such treatment as is adapted either to remove them altogether, or to palliate them so far as to remove or diminish the risk of their interfering to prevent the success of the operation. The previous habits of the patient as to diet, the use of strong drinks, smoking, &c, should be carefully taken into consideration. 1293. The treatment of the morbid states of the eye, which may complicate cataract, is discussed under their proper heads. In regard to the treatment of the various constitutional compli- cations, it would be out of place here to enter into detail. It is proper, however, to observe, that in some cases the abstrac- tion of blood may be necessary, besides restriction of diet, even to abstinence from all strong drink, and animal food too, though in these respects care should be taken not to interfere violently with confirmed habits. For the regulation of the bowels, re- peated purges may be required. In other cases, strengthening diet and tonic and even stimulating treatment may be called for. 1294. It need scarcely be remarked, that if the patient is subject to gout, rheumatism, or erysipelas, the operation should be carefully avoided, when there is reason to fear an attack is impending. Shortly after an attack, is the occasion which should be chosen. In any case, the operation is not to be undertaken while the patient has a foul tongue. 1295. On the morning of the operation, if there is no natural evacuation, a clyster should be given to procure one. 1296. The only special preparation of the eye for the opera- tion is the dilatation of the pupil, by means of the softened ex- tract of belladonna, smeared on the eyebrow and eyelids, two or three hours before. 1297. Season of the year and time of the day best adapted for operations for cataract.—The operations for cataract may be performed during mild and steady weather at any season; and such weather most usually occurs from March to the end of October. [In the middle portions of the United States, from June to the end of November.] Noon is the best time of the day for operating for cataract. 1298. Position of the patient, assistants, and operator.— The patient may either sit on a chair, or he may lie extended on a sofa or table with a pillow under his head. Infants are best secured by wrapping them in a shawl, to confine their arms and hands, and laying them on their backs on a table. OPERATIONS FOR CATARACT. 241 1299. When the patient sits, the operator usually stands, or, if he sits, it is on a high chair, before the patient, whilst an as- sistant stands behind to support his head, and to take charge of the upper eyelid. The patient's head should be held with the face looking somewhat upwards ; and in order to secure it in this position, the assistant supports it against his breast, and holds the chin by one hand, whilst the other—the right if the right eye, the left if the left eye is the subject of the operation— rests on the forehead ; with the latter hand the assistant secures the upper eyelid. The operator takes charge of the lower eyelid, and for this purpose he uses the forefinger, the middle finger being applied to the inner corner, ready to prevent the rolling inwards of the eyeball, the ring finger is bent to be out of the way, the little finger rests on the patient's opposite cheek: with the right hand the operator holds the instrument. 1300. The operator may, however, stand behind the pa- tient ; in which case, with one hand resting on the forehead, he secures the upper eyelid, whilst with the other he holds the in- strument. This may also be the position of the operator when the patient is extended on a sofa or table. 1301. If the operator is not ambidexter, he, when the pa- tient sits, stands before him, and takes charge of the lower eye- lid, if the operation is on the left eye ;—behind him, and takes charge of the upper eyelid, if on the right eye. When the pa- tient lies extended on a sofa or table, the operator still stands behind the head, if it is the right eye which is to be operated on; but if the left, then he must stand by the side of the pa- tient. In this case, the assistant stands at the head, and secures the upper eyelid; the operator himself secures the lower. 1302. In operating on the eye, it is of the greatest moment that there should be good light. The window should be direct- ed to the north, if possible. If there be more than one window in the room, the others should have the curtains drawn over them. In regard to the position of the patient to the light, it should be such, that the eye is fully exposed to the light, and that neither the operator's body nor his hand be interposed be- tween the eye and the light during the operation. 1303. Opening and securing of the eyelids.—The patient, assistant and operator being in their places, the next business is to open and secure the eyelids. The proper securing of the upper eyelid is a most important point; it is effected by apply- ing the points of two fingers, the fore and middle, or the mid- dle and ring finger, according to circumstances, against the broad border of the tarsus, the eyelashes being smoothly extended be- 16 242 OPERATIONS FOR CATARACT. tween the eyelids, and the surface of the fingers, and gently raising the eyelid, pressing the firm part of the eyelid back under the margin of the orbit, until the fingers come to press against that margin; the eyelashes are now interposed between the fingers and the margin of the orbit. The upper eyelid may thus be completely secured without any great force, and without the slightest pressure on the eyeball, without the eyeball even being touched. 1304. The lower eyelid is secured in a similar manner, and still more easily, with the forefinger, whilst the middle finger is applied over the caruncle. Fig. 16. Fig. 16. 1305. It is seldom necessary to employ a speculum for securing the upper eyelid, except in the case of children. 1306. When the eyelids are held apart unskillfully, folds of the conjunctiva are apt to be thrust out between the eyelids by the action of the orbicularis muscle, so that they almost bury the front of the eyeball, and consequently impede the operator. 1307. The eye not operated on, should be covered as a general rule. A compress of charpie is laid over the closed lids, and secured by a roller. If, however, the patient has com- EXTRACTION OF THE CATARACT. 243 plete command over himself, and can keep his gaze steadily fixed, the eye should be left uncovered, that he may direct it to some point, and thus properly direct and steady the eye to be operated on. EXTRACTION OF THE CATARACT. 1308. Extraction of the cataract may be effected through an incision, either in the cornea, or in the sclerotica. Extraction through an incision in the cornea, is the operation commonly practised ; extraction through a sclerotic incision not having been found so successful. 1309. The kind of cataract for the cure of which the opera- tion of extraction is most commonly undertaken, is the com- mon hard lenticular cataract of old persons. It is also per- formed in certain cases of capsulo-lenticular cataract, and in siliquose cataract; but these cases being for the present left out of the question, the reader's attention is requested to an account of the operation as it is performed for hard lenticular cataract in old persons. Extraction of the hard or common lenticular cataract of old persons. 1310. Conditions necessary for, or at least favourable to the successful performance of the operation. 1. Steadiness on the part of the patient during and after the operation, is especially necessary. 2. Large palpebral fissure, so that the eyelids may admit of being sufficiently separated, to allow the whole front of the eyeball to be duly exposed. 3. The eyeball neither much sunk nor very prominent. In the one case the section of the cornea cannot be well made; in the other, the healing of the wound does not proceed so favourably. 4. The cornea, healthy in structure, (an arcus senilis* is no impedi- ment,) and of due size and prominence. 5. The iris, free * Arcus Senilis (Gerontoxon) is an annular opacity of the cornea within its circumference, which occurs in advanced periods of life, though it is some- times observed below middle age. The opacity is about the twentieth or thirtieth of an inch broad, and has an equal breadth of nearly clear cornea intervening between it and the cir- cumference of the cornea. Arcus senilis appears first at the upper and lower parts of the cornea, and by and by extends all round, though this does not always happen. It is never so extensive as to obstruct vision. Arcus senilis must not, as above observed, be confounded with the bluish- white ring round the extreme margin of the cornea, commonly called arthri- tic, and seen in some cases of internal inflammation, particularly in old per- sons, (s. 831.) 244 EXTRACTION OF THE CATARACT. from synechia, and not inclined towards the cornea, so that the anterior chamber may be of good width. 6. The pupil natu- ral, freely contracting and dilating according to the degree of light. 1311. Conditions unfavourable to, or wholly forbidding, the performance of the operation.—Unsteadiness on the part of the patient; chronic cough; difficulty of breathing; very overhang- ing superior orbital margin and eyebrows; narrow palpebral fissure; very sunk or very prominent eyeball; the cornea un- healthy in structure, small and fiat; the anterior chamber conse- quently small; synechia, small pupil; and not widely dilatable, even by belladonna; or, and above all, a dissolved state of the vitreous body and its connections. 1312. When a dissolved state of the vitreous body exists, as it often does in old persons, the section of the cornea is, per- haps, no sooner made than the cataract, along with a greater or less quantity of the vitreous humour, bursts out from the eye; or, the cataract sinking down behind the iris, a large quantity of vitreous humour alone burst out. If the dissolution of the vitreous body be in a great degree, it will be evacuated wholly or in large quantity, and the eyeball may thus be destroyed, notwithstanding the utmost dexterity, delicacy, coolness, and circumspection on the part of the operator. But how is the existence of this state of the vitreous body ascertained before operation? (See ss. 1087, 1088.) 1313. If, during the operation of extraction on one eye, any indications of softening of the vitreous body should be observed, this ought to warn any one against proceeding at once to ope- rate on the other; because, during the second operation, the muscles of the eyes and eyelids are apt to be involuntarily con- tracted, and the vitreous humour of the eye already operated on squeezed out. 1314. It is to be observed, that in the eye in which the cataract has more lately formed, the vitreous body is less likely to be softened than in the other; so, that supposing it be de- termined to operate by extraction on both eyes at the same time, it would be advisable to operate first on that in which the cataract has more recently formed. ■ 1315. Prognosis.—When the case is one of common hard lenticular cataract, and when the other conditions are favour- able, the prognosis is good. Recovery of the eye, from the effects of the operation, sometimes takes place in a very short time; but usually some degree of external, or even anterior internal inflammation occurs, so that recovery is retarded. In EXTRACTION OF THE CATARACT. 245 general, recovery should not be calculated on, sooner than from four to six weeks; in some cases dangerous and destructive inflammation occurs, although the case appeared to be in all respects a proper one, and the operation well and successfully performed. 1316. The operation having succeeded as an operation, more perfect vision is in general obtained after extraction than after any other mode of operating. 1317. Instruments and dressings. Two of Beer's knives for making the section of the cornea. A set of Daviel's scissors, for enlarging the corneal incision if necessary, or the knife more commonly used for the purpose. A needle for lacerating the capsule. Daviel's curette or spoon. A fine hook, or slender-bladed forceps, for extracting or as- sisting out the lens, in case of its sinking in the vitreous humour. A pair of Maunoir's scissors. Several strips of black court plaster, about a quarter of an inch broad, and long enough to extend from the eyebrow to the cheek, over the eyelids. Two soft compresses of lint. A roller or broad ribbon. 1318. The operation of extracting a lenticular cataract, through an incision in the cornea, may be viewed as compre- hending two principal parts, viz., 1st, the section of the cornea; and 2d, the laceration of the capsule, and extraction of the lens. 1319. Section of the cornea.—This is usually considered the nicest, if not the most difficult part of the operation. It is made concentric with the margin of the cornea, and in order to be of sufficient size for the escape of the lens, about one-fortieth of an inch from the sclerotica, and to an extent corresponding to rather more than half—to the extent say of nine-sixteenths of the circumference of the cornea. This section may be made in the lower half of the cornea, fig. 17, or the upper half, fig. 18, or the outer and lower half, fig. 19, thus:— Fig. 17. Fig. 18. Fig. 19. 246 EXTRACTION OF THE CATARACT. 1320. The instrument usually employed for making the sec- tion of the cornea, is Beer's cataract knife, which is represented in the annexed figure. 1321. The back of the blade a is straight with Fig. 20. the handle, the cutting edge b oblique, and form- ing with the back at the point c an angle of about 18°. For about one-tenth of an inch from the point, the back is cutting, as well as the edge. 1322. The back of the blade generally, though blunt, should be thin, but in a line between the back and edge, extending from point to heel, the blade is thick, the thickness increasing gradually from point to heel on the one hand, and from the edge and back respectively on the other. The line in the direction of which the thickness is greatest, is indicated by d. This conformation imparts the necessary rigidity to the blade, and is farther of use, during the performance of the operation, in filling up the incision as it is made, and thus preventing the premature escape of the aqueous humour, until the completion of the sec- tion of the cornea, which is a very important condition for its successful performance. 1323. It may be remarked, that the great breadth of the blade towards the heel is quite unnecessary for the completion of the section of the cornea, as may be seen in figure 21, and is sometimes positively inconvenient during the operation, by coming into contact with the edge of the eyelid. All the part, therefore, comprised between e and/, fig. 20, might be advantageously cut away as far as the dotted line. 1324. The handle of the knife should be broad, as much as one-fifth or one-fourth of an inch broad, and flat, the flat sides to correspond to the flat surfaces of the blade. 1325. The mode in which the section of the cornea is made with the knife, which has now been described, is to pierce through the cornea on the temporal side into the anterior chamber, which constitutes the act of puncturation; then to push the point of the knife, the flat surfaces of the blade being to and from the operator, through the anterior cham- ber, across to the nasal side of the cornea, where the point of EXTRACTION OF THE CATARACT. 247 the knife is again made to pierce through the cornea from the anterior chamber, an act called counter-puncturation. By now continuing to push the knife onwards, it, by its increasing breadth, cuts itself out in the direction of the dotted line, fig. 21, and so the section of the cornea is completed. The section of the cornea thus 'comprehends three acts, viz., puncturation, counter-puncturation, and cutting out. 1326. Method of holding the cataract knife.—The handle is to be held not exactly in the middle, but rather nearer the blade; its flat surfaces being between the points of the fore and middle fingers on the one hand, and the point of the thumb on the other, and the general direction of the handle somewhat at right angles to the thumb. Fig. 22. Fis;. 22. 248 EXTRACTION OF THE CATARACT. 1327. By having the handle of the knife broad and flat, and by holding it in the manner just described, it is not liable to roll betwixt the fingers, and the little finger resting on the patient's cheek, all the manoeuvres after puncturation, can be readily executed by the movements of the fingers alone, so that the surfaces of the blade can be kept unerringly parallel to the surface of the iris, and the base of the cornea, during the pass- age of its point, through the anterior chamber: consequently its edge will have no tendency, either to cut abruptly out from the cornea; or, on the contrary, to be so inclined, as to come upon the sclerotica, and cut out there. 1328. The position of the patient, whose pupils should be dilated by belladonna, (s. 1296,) assistant and surgeon being arranged as above recommended (ss. 1298, et seq.), the opera- tion is proceeded with as follows:— 1329. Section of the cornea downwards—Puncturation. The surgeon holding the cataract knife* in the manner above described, and with its back upwards and horizontal, rests the hand by means of the little finger on the patient's cheek, in such a way, that the blade of the knife may be by its cor- responding flat surface close in front of the cornea, and with its point as far advanced towards the nose, as it must be, when counter-puncturation is effected. 1330. Things being thus disposed, the surgeon, after touch- ing the surface of the cornea, with the flat surface of the blade of the knife, to see whether or not the eye is disposed to start, and warning the patient not to hold his breath when the knife pierces, prepares for puncturation, by first retracting the fingers holding the knife, and then slightly turning the hand, so that the point of the knife may be brought opposite, and somewhat per- pendicular to the point of the cornea, where puncturation is to be made, viz., about one-fortieth of an inch from the temporal margin, and as much above the transverse diameter. The point of the knife should therefore be somewhat deeper than the handle. 1331. Watching his time, then, when the eye is directed steadily forwards, the surgeon by a quick but assured move- ment, enters the knife, back upwards, one surface looking back towards the temporal margin of the cornea, the other looking forwards and inwards, perpendicularly to the surface of the cornea, and pushes it on in the same direction, until it has just * The sharpness of the point of the knife should be previously tested, by making it pierce very thin leather put on the stretch. If the knife pierces without force, and without making any noise, the point is good. EXTRACTION OF THE CATARACT. 249 penetrated the thickness of the cornea, and thus gained the anterior chamber. 1332. Great care should be taken not to push it farther in, to avoid spitting the iris.- Should this happen, the point of the knife must be withdrawn so far, that it may get free from the iris; but in doing this, some aqueous humour is apt to escape, in which case the iris will fall before the edge of the knife, in its passage across the anterior chamber. 1333. The perpendicular direction recommended to be given to the point of the knife, in the act of puncturing the cornea, is to obviate the risk of the point of the knife being thrust obliquely into the substance of the cornea, instead of penetrat- ing directly through its substance into the anterior chamber. That the knife has been thrust into the substance of the cornea, and not penetrated into the anterior chamber, is readily per- ceived by the dull-looking way in which the knife shines through, in comparison to what it does when it is fairly in the anterior chamber; and also, by the continuance of resistance to the onward progress of the knife. All this can be readily illustrated, by practising on the eye of a sheep or pig. The remedy is to withdraw the knife, and commence the punctura- tion anew, and with more careful observance of the necessary precautions. 1335. Passage of the knife across the anterior chamber, and counter-puncturation.—Immediately on puncturation being effected, the handle of the knife is to be inclined backwards, by bringing the hand back into its former position, so that the surfaces of the blade may become parallel to the iris and base of the cornea. The handle of the knife is at the same time to be inclined a little downwards, so that the point may be direct- ed a little upwards, as if to make counter-puncturation at a point higher than is really intended, otherwise in consequence of the depression which the point of the knife necessarily ex- periences in its progress towards the opposite side of the cornea, counter-puncturation would fall too low, and the section of the cornea Avould consequently be too small. 1336. The knife, thus disposed with its point directed to- wards the place of counter-puncturation, is pushed steadily and quickly on through the anterior chamber, to the opposite side of the cornea, and until counter-puncturation is effected. The point of the cornea where this should take place is one-fortieth of an inch from its nasal margin, and corresponding to, or a little above, the transverse diameter. 1337. If, before counter-puncturation is effected, the aqueous 250 EXTRACTION OF THE CATARACT. humour should escape by any accident, such as the sudden movement of the eye away from the knife, in such quantity that the iris falls forward against the cornea, further proceedings should be desisted from, and the operation deferred until the restoration of the aqueous humour, and the subsidence of the reaction, if any, which may have taken place in consequence of the simple puncturation. Or if the eyeball should roll inwards and upwards so much that the surgeon cannot see the opposite side of the cornea, and if the patient cannot turn the eyeball right, it is better to withdraw the knife than counter-puncture at hazard. 1338. Cutting out.—Counter-puncturation being effected, a short pause is to be made, to allow any spasmodic action of the muscles of the eyeball to subside. Preparatory to cutting out, the surgeon, having now complete command over the eyeball, makes it turn rather outwards, in order that in completing the section of the cornea, the point of the knife may not come upon, and be stopped by, the parts at the inner canthus. 1339. In pushing the knife on in order to cut out, which is to be done slowly but steadily, its edge must not be pressed down against the substance of the cornea which it is cutting, but, by depressing somewhat the handle, the back of the knife should rather be kept pressed up against the upper angle of the wound of counter-puncturation. By this means the blade of the knife is made to fill both the incision and counter-incision in the cornea, in proportion as it makes them, and thus no room is given for an escape of aqueous humour. 1340. When the knife has almost cut itself out, a pause is to be made ; and if none of the aqueous humour has yet escaped, some may now be allowed to do so. After this, the tag of the cornea which remains is to be slowly and cautiously cut by a sawing motion. The upper eyelid is at the same time to be let go, and as soon as the tag is cut, and the knife withdrawn, the lower eyelid is to be allowed to rise, care being taken that its border does not interfere with the corneal incision. 1341. Whilst the cutting out is thus being accomplished, the patient is to be cautioned not to hold his breath, or make any effort to squeeze the eyelids together, for at this moment the lens, with a portion of vitreous body, if the latter is at all in a dissolved state, is apt to burst out. If there is much reason to fear this, it is advisable to leave the tag of cornea uncut, allow the eyelids to close, and cut the tag only after laceration of the capsule has been effected. EXTRACTION OF THE CATARACT. 251 1342. If, in cutting out, the iris should fall against the edge of the knife, in consequence of premature escape of aqueous humour, the surgeon should pause, and whilst pulling the eye forwards with the whole knife, apply the point of the middle finger against the cornea, and try by gentle pressure to disengage the iris from the edge of the knife, and to keep it so whilst completing the section. If this does not succeed, and if much of the iris lies before the edge of the knife, this instrument should be withdrawn, and the section completed as well as possible with the probe-pointed knife, or Daviel's scissors. But if a small part merely of the iris falls before its edge, the knife may be pushed on, even although the piece of the iris be cut off. If in consequence of this excision of a piece of the iris an opening is made, this and the pupil should be thrown into one by dividing the isthmus before concluding the operation. * 1343. Section of the cornea upward^.—This has of late years been the method preferred. The procedure differs from that above described only in the circumstances, that the edge of the knife is directed upwards—the back, which is directed downwards, as in the former case, being horizontal—and that the points of puncturation and counter-puncturation should be below, instead of above, the transverse diameter of the cornea. In this case also greater care is required at the time of com- pleting the section of the cornea, in withdrawing the knife, and allowing the upper eyelid to fall down, for in consequence of the tendency of the eyeball to roll up suddenly, the flap of the cornea is apt to be caught either by the knife or by the edge of the upper eyelid, and to be folded down. 1344. Section of the cornea in its outer and lower half— This was the section generally adopted by the first Wenzel, (who used a double-edged knife for the purpose,) and has again been pretty extensively practised by Professor Rosas, of Vienna, (who uses a Beer's knife, with a sharp-cutting back,) and the late Mr. Tyrrell, who used the common Beer's knife. To effect the section, puncturation is made on the tem- poral side, 45° above the horizontal diameter of the cornea, and counter-puncturation below the horizontal diameter on the nasal side; so that of the semicircular incision, one-fourth is above, and three-fourths below, the horizontal diameter. 1345. Section of the cornea too small.—How to be reme- died.__The section of the cornea may prove too small, either in consequence of the incision being too much within the mar- gin of the cornea, thus—fig. 23, 252 EXTRACTION OF THE CATARACT. Fig. 25. Fig. 23. Fig. 24. or not extending to the half of the circumference, as above, fig. 24. The first-mentioned defective section can scarcely be remedied, the second may be so very readily. 1346. For enlarging the section of the cornea when too small, a small probe-pointed knife, such as is here represented, fig. 25, is the instrument most recom- mended, because the incision made by it heals better than one made by scissors. If, however, the surgeon finds he can effect his purpose more easily by means of Daviel's scissors, the disadvantage attending an incision made by them is, on the whole, not so great as to deter from their use. 1347. When the knife is used, it is held as the cataract knife, and it is introduced through the inci- sion of the cornea flatways, its round and blunt point gliding against the posterior surface of the cornea, contact with the iris being avoided as much as pos- sible, and its edge directed against the angle where the incision is to be enlarged. By withdrawing the knife a little, the cornea is cut; the knife being again pushed in, it is again a little withdrawn, and an ad- ditional cut made and so on, cutting only on with- drawing the knife, until the wound is sufficiently en- larged, and that as much as possible in a line concen- tric with the margin of the cornea. 1348. When the scissors are had recourse to, Da- viel's should be those employed. Daviel's scissors have a double curve, to adapt them to make as direct a snip of the cornea as possible. Two pairs bent in opposite ways are consequently required. One pair to enlarge the incision, supposing the section down- wards, on the temporal side of the right eye, and on the nasal side of the left; or supposing the section upwards, to enlarge the incision on the temporal side of the left eye, and on the nasal side of the right. Another pair to meet the opposite circumstances. Figures 26 and 27. EXTRACTION OF THE CATARACT. 253 Fig. 26. Fig. 27. 1349. The way in which the scissors are to be held is this: __The thumb in one ring, the ring-finger in the other, the point of the fore-finger on the joint, the middle finger on the branch in the ring of which the ring-finger is. The thumb and ring- finger may be inserted into the rings, either from the convex or concave surface of the scissors, according to circumstances; but the convexity of the instrument ought of course always to be towards the eye. 1350. Supposing the eye operated on to be the left, that the 254 EXTRACTION OF THE CATARACT. section of the cornea is downwards, and that it is on the tem- poral side, the incision is to be enlarged, the pair of scissors to be used is that which, when held as above described, will pre- sent the concavity of its lateral curve towards the centre of the cornea. The blades then being sufficiently open, the point of the one next the centre of the cornea is to be introduced flat- ways behind the flap of the cornea, and carefully slid up be- tween the cornea and iris to opposite that part of the circum- ference of the cornea which is to be cut. 1351. There are now two precautions to be observed:— 1st. In order to avoid haggling, the edges of the scissors should be directed, as much as possible, at right angles to the part to be cut, which is done by turning the scissors a little on their axis towards the nose. 2d. In order that the cut may be made as large as is desired at one stroke, their points should extend somewhat beyond the point in the cornea to which it is wished to enlarge the incision, because during the stroke the instrument necessarily slips some- what back. 1352. General observations on the precautions to be ob- served in making the section of the cornea.—According to the direction in which the edge of the knife is inclined, when it pierces the cornea, and is passing across the anterior chamber, so must that of the section be. If the knife is properly held and entered, all that the surgeon has to do in carrying it across the anterior chamber, is to watch its point, so that the counter- puncturation may be made at the proper place; this being effected, the surgeon has complete command over the eyeball, and all that is now required is to push the knife steadily on in the manner above described, and it inevitably goes right. But if it has been ill entered at first, though the deviation of its sur- faces from parallelism with the surface of the iris and base of the cornea may have been very slight, the deviation of the edge from the right direction of course increases with the progres- sive movement of the knife, and then if attempts are made to bring the knife again into a proper direction, they cause the opening in the cornea already made to gape, and thus the aqueous humour is allowed to escape, so that the iris falls against the edge of the knife; and besides all this, undue and irregular pressure is exerted on the contents of the eye, so that the completion of the section of the cornea is perhaps followed by the bursting forth of a quantity of vitreous humour, with or without the lens. 1353. If the faulty direction of the edge of the knife is such EXTRACTION OF THE CATARACT. 255 that it will cut out too soon, so that the section will turn out too small, the operator should nevertheless proceed, and enlarge the incision afterwards. If, on the contrary, the direction of the edge of the knife is too much inclined towards the sclerotica, so that if the knife were pushed on it would cut both it and the conjunctiva, it should be withdrawn in time, and the section of the cornea completed with the probe-pointed knife or Daviel's scissors. 1354. Laceration of the capsule, and extraction of the lens, when the downward section has been made.—Different shaped instruments are in use for lacerating the capsule; sickle-shaped, or straight broad- FlS- 28- Fig. 29. pointed cataract needles, but the simplest in- strument is one like a common sewing needle, bent at the point (fig. 28). The instrument, of whatever form it may be, is commonly fixed on the same handle with the curette, (fig. 29,) which is employed for assisting in the extraction of the lens. 1355. The assistant having gently raised the upper eyelid, without making the slightest pressure on the eyeball, and the patient being directed to turn the eye a little upwards, the surgeon with one hand depresses the lower eyelid, and through it makes gentle pressure on the lower part of the eyeball, and with the other slips the bent needle with the con- vexity of its curve first behind the flap of the cornea, until opposite the pupil, and then up as far as he can behind the iris. This being done, he rotates the handle of the instrument so as to turn the point against the upper part of the cataract. By a rotatory movement now of the handle whilst held horizontally, he makes the point of the instrument lacerate the capsule from above downwards as far as the middle. He next, in a similar manner, lacerates the lower part of the capsule by a stroke from below, and before withdrawing the instrument, he makes in that part of the capsule exposed by the pupil several up and down strokes with the point of the instrument. 1356. In its natural state, the capsule, when punctured merely, will readily tear and allow the lens to escape; and although in lenticular cataract the same thing will often take 256 EXTRACTION OF THE CATARACT. place, it is proper not to trust to this, but to take pains to lace- rate the anterior capsule freely, as just described. 1357. The capsule having thus been freely lacerated, the instrument is to be carefully withdrawn with its convexity fore- most, so as not to hook the iris or cornea. 1358. It often happens that immediately on the laceration of the capsule, the lens begins to escape; if it does so, the sur- geon will at once proceed to help it out in the manner to be described below ; but if it does not, the eyelids are to be allowed to fall together for a minute or so before the extraction is pro- ceeded with. 1359. In the former case, the assistant still keeps the upper eyelid carefully elevated without making pressure on the eye- ball, whilst the operator, continuing to keep down the lower eyelid with one hand, takes the curette in the other, and watches the progress of the escape of the lens, the advance of its lower edge through the pupil, its clearing the pupil, and its final es- cape through the incision of the cornea. Whilst this is going on, the patient is to be directed to turn the eyeball upwards. No farther interference may be required, but if necessary, gen- tle pressure is to be made on the lower part of the eyeball, at some distance from the margin of the cornea, where the con- junctiva is reflected, and this may be done either by the sur- geon pressing the margin of the lower eyelid which he is holding against the eyeball, or employing the curette for the purpose. 1360. In the latter case, after the pause, the eyelids are opened as before, and the patient being directed to look up- wards, the surgeon makes gentle pressure on the lower part of the eyeball, when the lens will be seen to slide by its lower edge through the pupil, which it stretches, to raise the flap of the cornea, and finally make its escape through the incision. If its escape through the incision of the cornea should be stopped, the lens is to be helped out by a hook or by the curette, from between the lips of the incision. 1361. Laceration of the capsule, and extraction of the lens when the upward, or the downward and outward section has been made.—This part of the operation is effected in a manner essentially similar to that above described for the downward section; only in the one case, the laceration of the capsule is to be made from below upwards, and in the other from above downwards to below and outwards. In the extraction of the lens again, the patient should in the one case be directed to turn the eye downwards, and any pressure on the eyeball EXTRACTION OF THE CATARACT. 257 which may be necessary, is to be made with the curette on its upper part, whilst in the other the patient turns the eye inwards and upwards, and pressure with the curette is made on the lower and outer part of the eyeball. 1362. In its passage out, some of the soft exterior of the lens is often stripped off and retained in the aqueous chamber. No attempt need be made to remove this, as it becomes by and by absorbed. If, however, the lens should break in pieces, and a considerable piece be left in the anterior chamber, it should be scooped or hooked out. 1363. After a few minutes' rest to the patient, the surgeon gently opens the eyelids to see if the iris and flap of the cor- nea are in their proper position, and the pupil clear. If the iris and pupil do not appear to be quite right, the upper eyelid is allowed to close, and is to be rubbed gently with the finger over the front of the eyeball, and then quickly opened to the light, when the iris will contract, and will thus, along with the pupil, be brought into a proper position. This being the case, and the flap of the cornea in proper apposition, the eyelids are to be closed—first the upper and then the lower. 1364. If after laceration of the capsule, and moderate pres- sure on the eyeball, the lens does not advance, the surgeon must consider whether or not the section of the cornea is large enough, and whether or not the capsule has been sufficiently lacerated. If he is assured that everything is right in these two respects, he should consider whether, in consequence of adhe- sion, &c, the pupil is not restrained from yielding to allow of the passage of the lens through it. If this appears to be the case, the adhesions ought to be divided, and the pupil enlarged with Maunoir's scissors. (Fig. 30.) If still the cataract does not advance, an attempt is to be made to extract it with a hook. (Fig. 31.) In such a case, if any vitreous humour escape, which it is apt to do, the lens will fall back and sink below the pupil. 1365. Protrusion of the iris may take place after the lens has escaped. If uncomplicated with escape or protrusion of vitreous humour, it is in general readily remedied by drawing down the upper eyelid, and after rubbing the finger over it at the place corresponding to the cornea, suddenly raising it, and thus exposing the eye to the light. By this means, contraction of the pupil is excited, and the protrusion drawn in. If this does not succeed, attempts should be made to replace the pro- truded iris with the curette, and by a repetition of the above 17 258 EXTRACTION OF THE CATARACT. Fig. 30. Fig. 31. I manoeuvre. If the protruded iris appear to have aqueous humour pressing on it from behind, a small snip is to be made in it with scissors to allow the aqueous humour to escape; after that the iris will more readily return into its natural situation. 1366. Of all the untoward circumstances which may occur in performing the operation of extraction, the bursting out of the vitreous humour in greater or less quantity is assuredly that most to be dreaded. For though it may be promoted by undue pressure on the eyeball, either by the operator or assistant, restlessness of the eye or spasmodic contraction of the muscles of the eyeball at the time of completing the section of the cornea or afterwards, the con- EXTRACTION OF THE CATARACT. 259 dition on which it essentially depends is a softened or dissolved state of the vitreous body and its connections. 1367. When the vitreous body is of its natural consistence, and its connections unweakened, as in young persons, there is little danger of its escape,—nay, if its escape were desired, it would perhaps not be easy to produce it by any ordinary pressure. To be convinced of this, take the eye of an animal newly slaughtered, make a free section of the cornea, and then try to squeeze out the vitreous humour. It is only when the connections of the vitreous body have become dissolved by keeping the eye for twenty-four hours or so after death, that the vitreous body can be readily squeezed out. With the advance of age, however, softening of the vitreous body and its connec- tions, as above observed (s. 1088), tends to take place; hence it is that in the operation at present under consideration, viz., extraction of the common hard lenticular cataract of old per- sons, bursting out of the vitreous humour, with or without the lens, is so apt to .occur. 1368. Bursting out of the lens, together with a greater or less quantity of vitreous humour immediately on completing the section of the cornea.—In this case the operation is com- pleted, and whether it is likely to be followed by a good or bad result will, in a great measure, depend on the quantity of vitre- ous humour lost. If the quantity does not exceed one-fourth or one-fifth, it is possible for the eye to recover with pretty good vision; if more is lost, such an event is not to be hoped for. 1369. In any case the mode of procedure is to close the eyelids immediately, and after some time, cautiously open them to see how the flap of the cornea lies, and whether any of the hyaloid or the iris, as it is very apt to be, is protruded. If so, an attempt is to be made by the manoeuvres above de- scribed, to replace the iris, and bring the edges of the corneal wound together, as far as can be done preparatory to bandaging the eye. A portion of the hyaloid, however, may continue to protrude, and thus prevent the replacement of the iris and accu- rate closure of the corneal wound. All that can be done now is to close up the eyelids, and leave things to nature. Under the most favourable circumstances, the wound of the cornea heals slowly, with a broad cicatrice, the iris and hyaloid being involved in it, and the consequence is that the pupil is dislocated and distorted. Still, good vision may be restored. 1370. Vitreous humour may begin to escape without the lens,—In this case the small hook is immediately to be intro- 260 EXTRACTION OF THE CATARACT. duced, and the cataract hooked by its lower edge, and brought out as quickly as possible, a proceeding which demands great dexterity, coolness and circumspection on the part of the ope- rator. 1371. If the cataract should sink in the vitreous humour nearly or quite out of sight, some attempt may be made to hook it out, but not persisted in if unsuccessful. In this case it must be left, and the eye closed, otherwise the complete evacuation of the vitreous humour will inevitably take place. 1372. Bandaging of the eye and treatment after the opera- tion.—The flap of the cornea lying in proper apposition, the eyelids are to be closed. The upper eyelid is allowed to fall slowly over the eye, when the upper section has been made. If it has been the lower section, it must be carefully seen that the edge of the lower lid does not interfere with the lower part of the flap; if it does so, the lower lid should be ,kept some- what retracted by a strip of plaster, extending from it down on the cheek. 1373. Both eyes are to be kept closed, and for this purpose a light compress is to be laid over them when closed, and secured by a bandage, the middle of which is laid over the nape of the neck, where it may be sewed to the back of the night-cap, and the ends brought round over the eyes, crossed on the forehead, and then pinned to the sides of the night-cap. 1374. Another method of bandaging the eyes is to apply over them strips of court plaster, extending from the eyebrows to the cheeks, in order to keep them closed, and then hanging over them a fold of soft linen, to which is fixed a tape to tie round the head, thus : Fig. 32. EXTRACTION OF THE CATARACT. 261 1375. The patient need not be put to bed immediately after the operation, unless he desires it, but may recline on an easy chair or sofa, until about his usual bed-time. The room should be somewhat darkened, and perfect quietness observed in the house. The patient should refrain from speaking, and endea- vour to keep himself as composed as possible. His food should be so prepared as not to require chewing. 1376. At bed-time an opiate should not be omitted, if the patient is in the habit of taking one to procure sleep; if not in the habit, an opiate is to be given only if the patient is restless and not disposed to sleep. 1377. Some practitioners make it a practice to bleed the patient to ifviij or ^xvj, on the evening of the operation j if he has not been bled before ; but this is unnecessary, if the patient is, as he should be, in a proper condition at the time of the operation. It is time enough to take blood when symptoms of undue inflammation, such as pain in the eye, redness and swell- ing of the eyelids, begin to manifest themselves; and these symptoms ought to be carefully watched for from day to day. The third or fourth day is the time at which they most gene- rally occur. 1378. During the night the patient should be watched, lest by turning in bed or rubbing the eye with his hand while asleep, the eye should be injured. A good precaution is to secure the patient's hands to his side, so far that they may be prevented from being carried to the eye. 1379. The patient should lie on his back until at least the third day, when, if matters go on well, he may sit up in bed. On the fourth day, he may be allowed to get out of bed for a few hours in the afternoon. 1380. During the 24 or 48 hours succeeding extraction, the patient feels as if he had received a blow on the eye, and also from time to time experiences a slight smarting and pressing sensation, which is always relieved when a watery fluid, partly tears, partly aqueous humour, escapes from the eye. From these and encrusted Meibomian secretion, the eye is to be from time to time carefully cleansed with tepid water and a soft linen ' rag. The eye is not to be opened until the fourth or fifth day, but that things are going on well may be inferred if there is no pain, and the upper eyelid neither red nor swollen. On the fourth day, after the borders of the eyelids have been cleansed from any adherent matter, by means of tepid water, and a bit of soft lint, as just mentioned, and the strips of black court plaster, if they have been used, removed, the eye may be opened 262 EXTRACTION OF THE CATARACT. and looked at, but closed again, and so on from day to day, until the ninth or tenth. After that, the eyes being protected by a shade, the patient may freely open them. 1381. The corneal incision heals in the course of two or three days or even sooner, if there is nothing to prevent union by the first intention, such as prolapsus iridis, with or without prolapse of the vitreous body, or non-apposition of the edges of the incision. The incision, when enlarged by scissors, is apt not to heal completely by the first intention. 1382. When there'has been prolapse of part of the vitreous body at the time of the operation, after some days it presents itself as a viscid puriform slimy mass, hanging from the wound, and extending into the pupil. It by and by drops away, what of it remains within the eye gradually disappearing, and the pupil becoming black, though distorted, and drawn towards the corneal wound, which is healed by a broad cicatrix. The vision, however, may be good. 1383. Inflammation, fyc, occurring in consequence of the operation.—Though the cataract may have been extracted with- out accident, and though when the eye is bound up eyerything appears right, untoward circumstances may yet occur in the course of the following seven days. The most to be dreaded is inflammation, both external and anterior-internal, and which may be acute or slow, in either case impeding the union of the corneal incision and disposing to protrusion of the iris. 1384. In the acute inflammation, along with severe pain, the eyelids are swollen, red, and tender to the touch, the con- junctiva is red, and perhaps in a state of inflammatory chemosis, the edges of the corneal incision are opaque, swollen, and evert- ed, and the iris is discoloured. 1385. In the slow inflammation, which is apt to occur in old, weakly persons, the pain may not be less severe than in the acute, but the swelling of the eyelids is merely oedematous, and the chemosis of the conjunctiva serous. The edges of the corneal incision are whitish-gray; the iris is discoloured; pulse small and feeble ; the patient is low and restless. 1386. The acute inflammation requires to be treated active- ly by venesection and mercury, with low diet, and laxatives. Under the circumstances, the use of mercury has been dreaded, lest it might check the adhesive process, and thus prevent union of the section of the cornea. Experience, however, shows that after the operation of extraction the patient may be put under the use of mercury, without any prejudice to the union of the EXTRACTION OF THE CATARACT. 263 section of the cornea, but the reverse; for the mercury, reducing inflammation, promotes adhesion. 1387. The slow inflammation is equally dangerous with the acute, but requires to be treated on an opposite plan, viz., with cordials and generous diet. 1388. Secondary prolapsus iridis.—It has been above stated that prolapsus iridis is apt to take place at the time of the operation (primary prolapsus iridis); but though such has not occurred, the eye is not yet safe from prolapsus iridis, for in the course of the three or four days following the operation, the iris may yet protrude. This secondary prolapsus iridis may be occasioned by the bursting open of the half-healed cor- neal wound in consequence of some such effort as coughing; but it is generally owing to non-union of the corneal incision, and swelling of the iris, occasioned by the supervening inflam- mation. Behind the prolapsed iris there may be also protrusion of the vitreous body. 1389. If there is much inflammation, nothing should be done directly, except puncturing or cutting off a piece of the pro- truded iris, if it appears to be much distended by fluid be- hind. As the inflammation subsides, the protrusion sinks, and the iris will be involved in the cicatrice of the cornea, which will be broad and unsightly, whilst the pupil will be displaced and contracted, or altogether closed. Touching the protruded iris once a day or every second day with the nitrate Of silver pencil, will promote cicatrization. This may even be done from the first, if, instead of inflammation, there is defective action in the part. Extraction of capsulo-lenticular cataract. 1390. It is well known that an opaque capsule does not become dissolved and absorbed as the lens may be. In cap- sulo-lenticular cataract, therefore, it is necessary to remove the opaque capsule as well as the lens, out of the axis of vision. 1361. The section of the cornea being made in one or other of the ways above described, an attempt may be made before extracting the lens, to cut out by scratching with the point of the needle, a circular piece from the middle of the opaque ante- rior wall of the capsule. If this does not succeed, the lens is to be extracted in the usual way; and if the shreds of the opaque capsule occupy the axis of the pupil, an attempt may be made to extract them. For this purpose the slender-bladed hooked forceps is employed, (fig. 33.) This instrument, closed, being introduced through the incision of the cornea, and its point 264 EXTRACTION OF THE CATARACT. passed through the pupil, is opened, and the shreds of opaque capsule laid hold of, cautiously detached by a gentle twitch, and extracted. If there be any indications of a dissolved state of vitreous body, this attempt to remove an opaque capsule is not safe. It is better to leave it, and by a subsequent operation with the needle, displace it from the axis of vision. Fig. 33. Extraction of siliquose cataract. 1392. For the extraction of siliquose cata- ract a section one-third of the circumference of the cornea is sufficient. The section being made, the slender-bladed hooked for- ceps (fig. 33), is introduced, the cataract seized, cautiously detached from its connec- tions, by being twisted and moved in differ- ent directions, and extracted. 1393. Dr. Mackenzie recommends the siliquose cataract to be first detached and pushed into the anterior chamber by means of a cataract needle, introduced through the sclerotica, then the small section of the cor- nea to be made, a hook introduced, the cap- sule laid hold of and extracted. 1394. In cases of capsulo-lenticular and siliquose cataract, the same good vision is not in general restored by extraction, as in cases of common hard lenticular cataract; but this is because the retina in those cases is not in general quite so sound. The result may be as good, however, as is consistent with the nature of the case, and better than could be obtained by any other mode of ope- rating. Advantages and disadvantages of the three different sections of the cornea. 1395. The section downwards is on the whole more easily made than that upwards; the lower half of the cornea in gene- ral admitting of being better exposed, and thus more accessible to the knife than the upper half. 1396. When the section of the cornea downwards is com- pleted, the knife is more readily withdrawn, and the upper eye- lid can be allowed at once to fall gently down over the flap EXTRACTION OF THE CATARACT. 265 without disturbing it; whereas, when the section upwards is completed, more nicety is required in withdrawing the knife and letting down the upper eyelid, in order that its border may not catch the flap of the cornea, and turn it down. 1397. When the section downwards has been made, the escape of the lens takes place more easily, and less injuriously to the iris and corneal flap, than when the section upwards has been made, the tendency of the eyeball to roll upwards and inwards being a great impediment to the escape of the lens in the latter case. 1398. Escape of vitreous humour, it has been thought, takes place more readily when the section is downwards than when it is upwards, in consequence of the operation of gravity, but this is not the case. It has been above seen that this accident is owing to the vitreous body being in a dissolved state, and thus readily squeezed out by the spasmodic action of the muscles of the eyeball, an effort which is produced in whatever direction the section may be made, and whether the patient be lying horizontally or seated upright. 1399. Nor is prolapsus iridis more prone to take place when the section is downwards than when it is upwards ; but if it does take place when the section is downwards, the bad cica- trice which results is more readily seen, interferes more with vision, and if the pupil be closed, an artificial pupil cannot be made in so advantageous a situation afterwards. The contrary of all this is the case when the section is upwards : a bad cica- trice from protrusion of the iris and vitreous body is not seen, nor does it interfere with vision, and, supposing the pupil closed, the eye is in a better state for artificial pupil. 1400. The flap of the cornea when the section is upwards, is kept in good apposition by the upper eyelid, whereas, when the section is downwards, the tarsal border of the lower eyelid is apt to displace the edges of the incision, and so give rise to inflammation, prolapse of the iris, &c. This may, however, be obviated by careful bandaging. 1401. The section downwards and outwards has the advan- tages of the other two sections, with the additional one, accord- ing to Mr. Tyrrell, viz., that when prolapsus of the iris takes place after the operation to such an extent as to displace the pupil, the situation of the pupil downwards and outwards admits of more useful and perfect vision than when it is displaced upwards. 266 DISPLACEMENT OF THE CATARACT. DISPLACEMENT OF THE CATARACT AND ITS MODIFICATIONS. 1402. There are two modifications of the operation of dis- placement, viz., couching or simple depression, and reclination. In the one case the displaced lens has its anterior surface down- wards and somewhat forwards,—its posterior surface upwards and somewhat backwards,—its superior edge forwards and somewhat upwards,—its lower backwards and somewhat down- wards, thus:— Fig. 34. In the other case, the displaced lens has, at the same time that it was depressed, been made to turn back on its lower and outer margin, so that, its upper edge being forced back into the vitre- ous humour, its anterior surface comes to be uppermost, its posterior surface directed downwards, thus :— Fig. 35. 1403. Both couching and reclination of the cataract may be effected by introducing the cataract-needle, either through the sclerotica, that is, by sclerotic puncturation (scleroticonyxis), or through the cornea, that is, by corneal puncturation (kerato- nyxis). 1404. Reclination effecting all that couching can, and being in every respect a better operation, couching has altogether fallen into disuse. It is, therefore, unnecessary to say more about it here. RECLINATION OF THE CATARACT. 267 1405. Indications for the operation oj Fig. 36. Fig. 37. displacement.—The kind of cataract best fit- ted for displacement is the same as that best / fitted for extraction. Whether or not, there- fore, displacement should be performed instead of extraction, will depend upon the absence of the conditions necessary for, or at least favourable to the successful performance of extraction, (s. 1310,) or the existence of the conditions unfavourable to or wholly forbid- J4 1, ding it, (s. 1311.) O |Q 1406. Prognosis.—The success of dis- "T placement is apt to be marred by the occur- . rence of posterior internal inflammation either of an acute character, supervening immediately on the operation, or of a slow destructive cha- racter, coming on some time subsequently, and leading to loss of sensibility of the retina. The displaced lens, if disengaged from its cap- sule, may eventually disappear, or be reduced to a small size by solution and absorption. In many cases, however, it does not dissolve, and is always apt to rise again. 1407. Instrument and dressing. — The only instrument required is a lance-shaped cataract-needle, either straight or curved. The sharpness of its point is tested in the same way as above mentioned for the cataract-knife. The dressings are the same as above mention- ed for extraction. Reclination by sclerotic puncturation. 1408. For the convenience of description, the operation may be supposed to be divided into different steps. 1409. Theflrst step comprehends the punc- turation and the introduction of the needle ( [ j into the posterior chamber, so that its lance head is seen through the pupil. The point of puncturation should be about three-twentieths of an inch from the temporal margin of the cornea, and in the line of its transverse diameter.* * The direction to introduce the needle either above or below the trans- verse diameter of the eye is that which is most generally given; and the 268 RECLINATION OF THE CATARACT. 1410. The second step comprehends the reclination of the cataract. 1411. The third step comprehends the free laceration of the anterior wall of the capsule, and the withdrawing of the needle from the eye. 1412. The pupils of the patient should be well dilated pre- paratory to the operation. 1413. The position of the patient, assistant and operator, is arranged as above recommended, (ss. 1298, et seq.) 1414. Method of holding the cataract needle.—The handle of the needle is to be held between the fore and middle fingers on the one hand, and the thumb on the other, much in the same way as above recommended for the cataract knife. 1415. Puncturation and introduction of the needle into the posterior chamber.—The surgeon thus holding the needle, and resting his hand by the little finger on the patient's cheek, dis- poses it in such a way, that the blade of the needle is close in front of the cornea, in a line corresponding to the transverse diameter of the latter, and its point extending to opposite the nasal margin of the dilated pupil. He now prepares for punc- turation, by retracting the fingers holding the needle, and slightly turning the hand, so that the point of the instrument may be presented to the point of the sclerotica, where puncturation is to be made. 1416. If it be a straight needle that is used, its point, with the cutting edges looking to and from the cornea, the flat sur- faces upwards and downwards, is directed perpendicularly to the surface of the eyeball at the place above-mentioned, and steadily thrust in a direction towards the centre of the eyeball, but no deeper than until the lance head of the instrument disr appears. 1417. When a curved needle is used, its convexity should look upwards, and its concavity downwards in making the puncture; and in order that the point may be applied perpen- dicularly to the place to be punctured, it is necessary to de- press the handle of the instrument; but, of course, in propor- tion as the instrument penetrates, the handle is raised to the horizontal. 1418. The handle of the instrument is now to be rotated reason assigned for it is, that the long ciliary artery runs in the line of the transverse diameter ; but as at about a quarter of an inch from the iris, the long ciliary artery of the temporal side divides at an acute angle into two branches, an upper and a lower, it is obvious that the artery cannot be touched, and the surest way to avoid the branches is, to enter the needle as above recommended. RECLINATION OF THE CATARACT. 269 one quarter round its axis, so as to bring the cutting edges to look upwards and downwards, its surfaces backwards and for- wards ; or if the needle be a curved one, the convexity of the curve forwards, the concavity backwards. The handle is at the same time inclined well back towards the temple of the patient, in order that the lance head of the instrument may be so directed, that when pushed on, it will pass between the cili- ary body and the circumference of the lens into the posterior chamber, when it will be seen through the pupil with one sur- face looking forward, the other towards the cataract, and its edges upwards and downwards. Fig. 38. Fig. 38. 1419. In conducting the point of the needle between the ciliary body and the circumference of the lens, care should be taken not to spit the ciliary body on the one hand, or the lens on the other. If this should occur, the needle ought to be a little withdrawn, to get its point free again, before pushing it on. In entering the posterior chamber, the point of the needle is apt to spit the iris, especially if the needle be a straight one. The remedy for this, also, is to withdraw the instrument, until its point gets free, when it may again be pushed on. The im- portance of having the point of the needle free is evident. Again, the point of the needle may be made to project through the pupil, and spit the inner surface of the cornea. 1420. Reclination of the cataract.—Being sure that the point of the needle is free from entanglement, the surgeon ap- plies its lance head flat against the lens, a little above its trans- verse diameter, (if the needle is a curved one, it is by its con- cave surface that its lance head is to be applied to the lens,) and then by moving the handle of the instrument gently forwards a little, he presses back the upper part of the lens, in order to loosen the connections of the cataract, and to see that there are no adhesions between it and the iris. There being none, he continues to press back the lens steadily, but slowly. When 270 RECLINATION OF THE CATARACT. the upper part of the lens has yielded to this backward pres- sure, he rotates the needle slightly to keep it flat on the surface of the lens, and then presses the latter downwards and back- wards, by gently raising the handle of the instrument upwards and forwards. The lens being thus depressed, is to be moved a little backwards, if its lower edge now become anterior should appear to press on the iris or ciliary body. 1421. If the needle used is a curved one, it will be neces- sary in order to complete the depression, to apply the convex- ity of its lance head to the cataract. This is done, by de- pressing the handle a very little, so as to lift the lance head from off the cataract, and then rotating it one-half round its axis. 1422. Laceration of the anterior wall of the capsule, and the withdrawing of the needle from the eye.—Having for half a minute or so, kept the point of the instrument resting on the depressed cataract to prevent it from rising, the surgeon now lifts it slowly from off the cataract, by lowering the handle. Seeing that the cataract does not rise, he brings the head of the instrument back into the posterior chamber, by moving the handle a little backwards. Having here executed with the point of the needle such movements as are calculated to ensure the laceration of the anterior wall of the capsule, the surgeon still retains the instrument within the eye for half a minute longer. The cataract remaining depressed, the needle may now be withdrawn from the eye, by a series of manoeuvres exactly the converse of those performed in introducing it. This is espe- cially to be attended to, when its head comes to the puncture in the coats; here it is to be so rotated, that the surfaces shall be above and below as at the introduction of it, and then it is to be drawn out at right angles to the surface of the sclerotica, for which purpose, when the needle is curved, its handle must be depressed in proportion as the head is withdrawn. 1423. If instead of being hard, as was supposed, the cataract should be found friable, breaking under the needle, reclination ought not of course to be persisted in, but the anterior wall of the capsule is to be freely lacerated, and the lens left to be dis- solved and absorbed; in short, division is to be substituted for reclination. 1424. Again, should it happen that the lens is fluid, and that when the capsule is opened by the needle, it escapes, and min- gles with the aqueous humour, rendering it turbid, all that remains to be done, is immediately to lacerate the anterior wall of the capsule as freely as possible. RECLINATION OF THE CATARACT. 271 1425. If adhesions are found to exist between the iris and anterior wall of the capsule, they are to be separated if slight; if not, they must be left, and a central opening made in the anterior wall of the capsule, and the lens, after the posterior capsule is lacerated, is to be reclined. Division, however, if the case admits of it, would be better. 1426. Reclination as now described, is in general readily effected in the common lenticular cataract of old people; but sometimes the cataract rises as soon as the point of the needle is withdrawn from it, and this over and over again. Such a cataract has been called elastic cataract. 1427. The cause of the elastic re-ascension of the cataract is, I am disposed to believe, that in such cases the vitreous body still possesses its natural consistence, and therefore resists the sinking of the lens into its substance, as every one who has been accustomed to dissect healthy eyes, knows the vitreous body will do. Moreover, the circumferential connections of the lens are as yet unweakened. 1428. A persistence in attempts at displacement in such a case, would prove extremely detrimental to the internal struc- ture of the eye. The attempt, therefore, ought not to be re- peated, until the posterior wall of the capsule has been lacerated, and a breach made in the vitreous body, for the reception of the reclined lens. 1429. In order to do this, the needle is to be withdrawn from the posterior chamber, and indeed so far, that its lance head merely is within the eye. The head with its cutting edges upwards and downwards—if a curved needle, the concave sur- face of course forwards,—is then to be directed against the posterior wall of the capsule, and made to lacerate it and the vitreous body behind and below it, to the necessary extent. 1430. Having effected this, the surgeon withdrawing the instrument now so far, that its neck comes again to correspond to the point of puncture, as it did when first introduced, and assuring himself by the marks on the handle, that the edges of the lance head are directed upwards and downwards; and, if the needle be a curved one, that the convexity of the curve is forwards, and the concavity backwards, inclines the handle of the instrument well back towards the temple of the patient, and proceeds as before to push it into the posterior chamber, and to recline the lens. 1431. In order to anticipate the necessity of lacerating the posterior capsule and vitreous body subsequently, some surgeons do so at once, before pushing the needle into the posterior 272 RECLINATION OF THE CATARACT. chamber, and proceeding to the reclination. I would, however, remark, that when the vitreous body is of such firm consistence as to resist the lens being forced into its substance, extraction of the cataract would be a much better and safer operation, if there existed no particular indication of any weight against it. 1432. The lens may, instead of going down before the needle, suddenly burst through the pupil into the anterior chamber. In such a case, if it appears that it was on account of the firm- ness of the vitreous body that the lens did not yield to the needle, the surgeon should immediately proceed to extraction; but if it appears that the vitreous body is dissolved, the connec- tions of the lens weakened, and that on these accounts it was that the lens slipt into the anterior chamber, it would be safer practice, instead of extracting, to endeavour with the needle to bring the cataract back through the pupil, and to depress it. 1433. If extraction be had recourse to, it will be sufficient to make a section of one-third only of the circumference of the cornea. This being done, a hook is introduced, the lens laid hold of, and extracted. Reclination by corneal puncturation. 1434. The instrument for this operation is the curved cataract needle. 1435. The pupil should be well dilated, preparatory to the operation, and the position of the patient, assistant, and operator, arranged as above recommended, (ss. 1298, et seq.) 1436. The needle is held between the thumb on the one side, and the fore and middle fingers on the other. The side of the handle on which the thumb is, corresponds to the convexity of the instrument; that on which the fore and middle fingers are, to the concavity. 1437. The first F5S- 39- step comprehends the puncturation, the ad- vance of the point of the needle through the dilated pupil, towards the cataract, and the application of the con- vexity of the needle against the upper part of the anterior surface of the cataract. 1438. Tlie second step is the reclination of the cataract. RECLINATION OF THE CATARACT. 273 1439. The third step is the withdrawing of the needle from the eye. ' 1440. Puncturation, fyc.—The point of the cornea where puncturation is made, is about one-twentieth of an inch below its centre. 1441. Holding the needle as above directed, the operator directs the lance head of it towards the place of puncturation in such a way that the convexity of the curve is downwards, the concavity upwards, the extreme point perpendicular. The handle of the needle must therefore be directed upwards. Fig. 39. 1442. When the eye is in a proper position, the operator pierces the cornea perpendicularly, with a quick but steady thrust, executed solely by the movements of the thumb and fingers holding the instrument. When the lance head of the needle has penetrated as far as the middle of its curve, the handle of the needle is to be gradually depressed towards the cheek, the puncturation completed, and the needle pushed on through the pupil, with the point upwards, and convexity of its curve towards the upper part of the cataract behind the upper part of the iris. Fig. 39. 1443. Reclination of the cataract.—Having applied the con- vexity of the needle against the upper part of the anterior sur- face of the cataract, and right in the middle line, the operator raises, gently at first, the handle of the instrument. The in- strument acting as a lever, the fulcrum being the point of punc- turation in the cornea, the point of the needle is by this move- ment made to press back the upper part of the cataract. 1444. When the operator sees that the upper part of the cataract yields, he continues to raise the handle of the instru- ment firmly and steadily, thus turning the cataract before the needle downwards and backwards, and sinking it in the vitreous humour. 1445. Having kept the point of the needle for half a minute or so resting on the reclined lens to prevent it from rising, the surgeon now withdraws it a little slowly, still keeping the handle elevated, and watches for another half minute whether or not it is disposed to rise again. If not, he continues to with- draw the needle still in the same direction until it is quite free of the cataract and the vitreous humour immediately surround- ing, when he depresses the handle, and then brings its point again into the pupil. 1446. Withdrawing of the needle.—The cataract not rising, the needle, after another pause, is finally withdrawn from the eye. And this is done by drawing it out in a horizontal direc- 18 274 DIVISION OF THE CATARACT. tion, until the middle of the curve head becomes engaged in the puncture of the cornea, when the handle is to be raised, so that the extreme point may be withdrawn at right angles to the place of puncturation, as it was introduced. 1447. In this operation, care is to be taken that the pupillary margin of the iris is not caught by the needle, and during the reclination, that the lower pupillary margin of the iris be not pressed on. 1448. In elastic re-ascension of the cataract, attempts at reclination should not be persisted in, but the plan of operation relinquished. In this case, laceration of the vitreous body and posterior capsule cannot be effected, as it can in reclination by sclerotic puncturation. 1449. Reclination by corneal puncturation has not been found to answer so well as that by sclerotic puncturation, and there- fore has fallen into disuse. 1450. Bandaging and after-treatment.—The light fold of linen, (s. 1374,) to hang over both eyes, is sufficient bandage. In other respects, the same general management is to be adopted as above recommended after extraction. 1451. Accidents attendant on the operation of reclination. —Amaurosis may be at once occasioned by the pressure of the reclined lens. Should this happen, the needle must be re- introduced, and the lens raised a little, so as to relieve the pressure. 1452. In the course of a few hours after the operation, vomiting sometimes occurs. Re-ascension of the lens may be thereby occasioned. 1453. Acute internal inflammation of the eye is apt to he excited by the operation. Most frequently, however, the super- vening inflammation is of a chronic character, ending in disor- ganization of the eye and loss of vision. The inflammation appears to be at first posterior internal, with exudation on the surface of the retina, and into the vitreous humour, but by and by extending to the anterior segment of the eye. It commences from four to eight days after the operation. When the opera- tion is performed by corneal puncturation, corneitis and iritis are apt to be excited primarily. DIVISION OF THE CATARACT. 1454. The object of this operation is to lacerate the capsule, and divide the lens, so that the latter may be gradually dissolved DIVISION OF THE CATARACT. 275 and absorbed, and thus ultimately altogether removed from the eye. 1455. Considered as an operation, this is the most simple of all those for cataract, both in performance and in the extent of injury necessarily inflicted on the eye. 1456. Indications.—Division is indicated in:— 1st. Soft, or fluid cataracts,—the cataracts of most common occurrence in early life. To this head belongs congenital cata- ract. 2d. Sometimes in the common cataract of old people, divi- sion of the capsule is had recourse to in order that the lens may, by solution and absorption of its exterior part, be dimin- ished in size preparatory to extraction through a small section of the cornea. 1457. Prognosis.—In the cases proper for the operation, the prognosis is good. There is in general little reaction, but though the lens may be perfectly absorbed, the capsule, which does not admit of solution and absorption, if not already opaque, may become so, and form what is called secondary cataract. To anticipate this, the anterior wall of the capsule should, dur- ing the first operation, be as completely cut up as possible at the part corresponding to the pupil. The rapidity with which solution and absorption go on, varies from a few days to seve- ral months. In general it may be said that in children the ab- sorption proceeds more quickly than in adults. 1458. One operation may suffice, but, generally, solution proceeding slowly, the operation requires to be repeated, and that more than once. This, as the operation is so simple and painless, is no great objection. The interval between the repe- titions of the operation should be about six weeks. 1459. It is best to operate on both eyes at the same time. I have observed the solution to proceed more quickly after the operation on both eyes at the same time, than after the opera- tion on one eye only. When the eye becomes inflamed, solu- tion appears to be arrested. 1460. If the retina was previously quite sound, a perfect restoration of vision may be calculated on, if solution and ab- sorption go on pretty quickly; if not, by the time the cataract disappears, the sensibility of the retina may be found impaired. 1461. The operation of division may be performed either by sclerotic puncturation, or by corneal puncturation. Division of the cataract by sclerotic puncturation. 1462. The instrument best adapted for this operation is a 276 DIVISION OF THE CATARACT. curved lance-shaped needle. The pupil should be well dilated, and the patient, assistant, and operator placed as above recom- mended (s. 1298). 1463. First step.—This comprehends the puncturation and the introduction of the needle into the posterior chamber, so that its lance-head is seen through the pupil, and is altogether the same as the first step of reclination by sclerotic punctura- tion. In performing it the same precautions require to be ob- served to avoid spitting the ciliary processes, the lens or the iris. 1464. The second step in division comprehends the lacera- tion of the anterior wall of the capsule and the division of the lens, so far as is considered necessary, if a first operation on the eye; or the further division of the lens if it be a repetition of an operation. 1465. The laceration of the anterior wall of the capsule is effected in the first instance, by a number of vertical incisions in the part of it corresponding to the pupil, made by slight rota- tory movements of the handle of the needle, whilst the point of its curved lance-head is directed against the surface of the cataract. The vertical strips into which the middle of the cap- sule is thus divided, are then to be cut across horizontally, by directing one of the edges of the needle against them, and pressing it back through them into the substance of the cataract, which is done by slightly moving the handle of the instrument forwards. 1466. Division of the lens.—Having thus freely divided the capsule, the surgeon turns the sharp point of the needle against the lens opposite the pupil, and by slight rotatory movements of the handle of the instrument, breaks up its substance; if the lens is firm enough, he shaves off pieces with the edge of the lance-head of the needle, its concavity being directed forwards, and spoons the detached fragments into the anterior chamber. 1467. It is to be remembered, that it is better not to risk re- action by attempting too much at one time, in the way of break- ing up the lens, but the capsule ought always to be freely lace- rated at first. Especial care should be taken not to displace the whole lens, or even any considerable piece of it unbroken up. 1468. The third step.—This comprehends the withdrawing of the needle from the eye, and is effected by a series of ma- noeuvres, exactly the converse of those performed in introducing it. Especial care should be taken, in withdrawing the needle through the puncture in the coats, to rotate it so that the sur- faces of its lance-head shall be—the convex one upwards, and the concave one downwards,—as when introduced, and also to r DIVISION OF THE CATARACT. 277 depress the handle in proportion as the curved lance-head is withdrawn through the puncture. Division of the cataract by corneal puncturation. 1469. The instrument with which the performance of this operation is most simple, is a straight needle ground flat on the sides towards the point, so that as it penetrates the cornea, it fills completely the puncture, though not in a forced manner, and thus prevents the escape of aqueous humour. 1470. Preparatory to this operation, the pupil should be well dilated by belladonna. 1471. First step.—This comprehends the puncturation and the advance of the point of the needle through the dilated pupil towards the cataract. Fig. 40. 1472. The point of the cornea where the needle is to be made to pierce, is about half way between its centre and its outer and lower margin. 1473. The flat surfaces of the needle being the one towards the centre of the cornea, the other towards the margin, the point of the instrument is directed perpendicularly to the place above indicated, when it is to be made to pierce by a quick thrust, executed solely by the movements of the fingers. Having thus pierced the cornea, the handle of the instrument is depressed, and its point steadily pushed on towards the cataract, still by the movements of the fingers. 1474. Second step.—This comprehends the laceration of the anterior capsule if a first operation, or the breaking up of the lens, if a repetition. 1475. One of the edges of the instrument being directed against the capsule, one or more incisions are to be made in it from above and outwards, downwards and inwards, by a lever- movement of the handle of the needle. 1476. The division of the lens is effected, so far as is proper, by similar incisions. 1477. Third step.—This comprehends the withdrawing of 278 CONGENITAL CATARACT. the needle from the eye. In doing this, the surfaces of the instrument are to be directed in the same way as when it was introduced. 1478. Treatment and accidents after division.—The treat- ment after division, is the same in general as after displacement, except that the pupil is to be kept dilated. 1479. Vomiting often occurs after division through the cor- nea, especially when the cataract is fluid, and may continue several hours. Opiates are to be given to relieve it. 1480. When the operation is performed by corneal punctu- ration, corneitis, aquo-capsulitis and iritis are not unfrequently excited, and are apt to prove very stubborn and destructive to the eye. 1481. In cases of cataract complicated with extensive syne- chia posterior and contraction of the pupil, the consequence of iritis, the late Mr. Tyrrell recommended a modification of divi- sion by corneal puncturation, which he designated drilling. 1482. He passed a very fine straight needle, of uniform thickness, somewhat obliquely through the cornea at the outer part; and then, directing the point towards the anterior capsule of the lens, close to the inner margin of the pupil, (taking care not to injure the iris,) and causing the instrument to penetrate the capsule, and enter the substance of the lens, to the extent of about one-sixteenth of an inch, he rotated the handle of the needle between the fore-finger and thumb, so as to make the point act as a drill, and then withdrew the needle. An open- ing was thus secured more free than could be effected by a sim- ple puncture. 1483. He usually had to repeat this operation seven or eight times at intervals of from three to five weeks, taking care to puncture the opaque capsule in a fresh place at each operation, before the pupil was cleared. 1484. The operation in no instance produced inflammation of any consequence, and did not confine the patient for more than two or three days. 1485. In a few instances it was necessary to make an arti- ficial pupil subsequently by incision with Maunoir's scissors. See Artificial Pupil. Congenital Cataract. 1486. This is generally lenticular at first, but eventually be- comes capsulo-lenticular; and if left to itself, it may degenerate into siliquose cataract. OPERATIONS FOR CATARACT COMPARED. 279 1487. The operation for congenital cataract is division (ss. 1454 et seq.), by sclerotic puncturation, if the patient be still an infant; if already some years old, either this or the operation by corneal puncturation. 1488. The period after birth at which the operation should be performed, is before teething commences, or soon after it is completed, (s. 1291.) Secondary Cataract. 1489. After the operation of extraction of the lens, but espe- cially after division, the capsule is apt to become opaque and obstruct the pupil. This forms secondary capsular cataract. What is called secondary lenticular cataract, is merely some portion of the cataractous lens remaining, obstructing the pupil, after any of the operations above described. It in general re- quires no interference, except keeping the pupil dilated by bel- ladonna, being sooner or later absorbed. 1490. Operation for secondary capsular cataract.—At the same time that the capsule becomes opaque, it is apt to become thickened and very tough; it may not therefore be easy to divide it with the needle, so as to make an opening through it, opposite the pupil, but this should be first attempted; though the opaque capsule may often be detached in a mass, it does not admit readily of being depressed, as it always tends to rise again. This is owing to the resistance of the vitreous body, if sound, or if in a dissolved state to the opaque capsule being lighter than the fluid. In the former case, the opaque capsule should be extracted through a email section of the cornea, as above recommended for siliquose cataract; in the latter case, the capsule should be detached from below, and pushed upwards behind the iris, where it will float out of the way of vision. The same proceeding should be adopted in siliquose cataract, if there is reason to suppos'e that the vitreous body is in a state of dissolution. Comparative advantages and disadvantages of extraction, displacement and division. 1491. By the operation of extraction, the cataract is re- moved wholly and at once from the eye, and very good vision restored; but the operation is a nice, if not a very difficult one, and liable to the occurrence of the various untoward cir- cumstances above mentioned, by which its success is readily marred. 1492. The operation of displacement, which may be per- 280 CATARACT GLASSES. formed in the same cases as extraction, is neither so nice nor so difficult an operation, does not expose the eye to the same risk of immediate destruction, and though the cataract is apt to return to its former place, the operation may be repeated; but though displacement may have succeeded as an operation, and vision be restored, the eye is not so safe as after successful ex- traction, but, as above mentioned (s. 1453), is liable to become affected with internal inflammation, which ends in amaurosis. 1493. Extraction thus possesses a decided advantage over displacement, and is therefore generally preferred, except when the unfavourable complications above mentioned exist, (s. 1311.) 1494. The degree of softening of the vitreous body requisite to admit of safe displacement of the lens is not so great as to forbid extraction, but of course, if, in the cases in which the vitreous body is so much dissolved, that the displaced lens is apt to float up again, displacement be contra-indicated, extrac- tion is much more so. 1495. All other things being equal, it might perhaps be laid down as a general proposition, that in the very cases in which displacement admits of being most readily and safely performed, extraction is less safe, whilst, on the other hand, in the cases in which, in consequence of the soundness of the vitreous body, extraction is most safely and easily performed, displacement is least so. "1496. As the cases for which division is best fitted are differ- ent from those in which extraction or displacement is indicated, there is no comparison to be made between them. It is, how- ever, to be observed, that a combination of division and extrac- tion is sometimes had recourse to in cases of common lenticular cataract of old people. The object of having recourse to this compound operation is, as above mentioned, (s. 1456,) that the lens may, by solution and absorption of its soft exterior part, be reduced to its hard nucleus, which, in consequence of its small size, will admit of being extracted through a small section of the cornea. Cataract glasses. 1497. The difference in refractive power between the air and the cornea being much greater than between the aqueous humour and crystaline body, the greatest amount of refraction which the rays of light undergo in the eye, in order that they may converge to foci on the retina, is that effected by the cor- nea on their first entrance. The crystaline body contributes OPERATIONS FOR ARTIFICIAL PUPIL. 281 comparatively little to the convergency. Hence, vision, after a successful operation for cataract, may be still tolerably dis- tinct for objects at a certain distance. Still, in order, that it may be perfectly distinct, the use of convex glasses is required. 1498. But as with the loss of the crystaline body, there is loss of the power of the eye to accommodate itself to different distances, except so far as variations in the size of the pupil contribute to this effect, glasses of different degrees of convexity are required according as the patient wishes to view near or distant objects. Thus, convex lenses of two and a half inches focus are generally required for reading, and lenses of four and a half inches focus for viewing distant objects. 1499. Of course before fixing on any particular powers, the patient will try which suit him best, and the test which should guide him in his choice is, that when the spectacles are put on, or, if hand-glasses, when they are held immediately before the eyes, he sees objects distinctly at the same distance as he saw them before he became blind. 1500. Recourse is not to be had to the use of cataract glasses until the eyes have perfectly recovered from the operation, and have been so for some time. Section III.—OPERATIONS FOR ARTIFICIAL PUPIL. (Conformatio pupillae artificialis—Coremorphosis—Coreplastice.) 1501. An artificial pupil is an opening made in the iris, to serve as a substitute for the natural pupil, when this is either covered by extensive central opacity of the cornea, with or without being contracted, or complicated with synechia; or when it is actually obliterated, with or without being compli- cated writh opacity of the cornea or synechia, so that the rays of light can no longer be transmitted through it to the retina. 1502. There are three principal modes of operating for arti- ficial pupil which may be had recourse to, according to the nature of the case, viz., first, making the opening in the iris, by means of a simple incision or incisions—the operation for artificial pupil by incision. Second, making the opening by cutting out a piece of the iris—the operation by excision. Third, instead of actually making an opening in the iris, de- taching the membrane at some part of its circumference from its ciliary connection—the operation by separation. 282 OPERATIONS FOR ARTIFICIAL PUPIL. 1503., In some cases, the natural pupil admits of being so freed, as to be again available for the transmission of light to the retina. The operations by which this is effected, though not strictly operations for artificial pupil, are properly enough referred to the same head, as both in their performance and in their object they closely agree. The operations are: First, the restoration to its natural position of the pupil dragged to oppo- site a leucoma, by partial anterior synechia, by means of ab- scission of the band of adhesion. Second, the dislocation of the natural pupil to opposite a clear part of the cornea. 1504. In the cases in which an artificial pupil is required, the crystaline body may be healthy, or it may have been re- moved by a previous operation for cataract (of which operation the condition requiring the formation of an artificial pupil may be an effect) or it may be cataractous. In the first case, the crystaline must, if possible, be preserved untouched; in the last case, the operation for artificial pupil will require to be combined with that for cataract. General conditions necessary, or at least favourable, to the success of operations for artificial pupil. 1505. An operation for artificial pupil is not to be thought of, unless the patient has lost all useful vision with both eyes; and then, only when there is reasonable evidence that the retina is still sound. 1506. Before the operation is undertaken, the eye must have quite recovered from the inflammation which has been the cause, or been co-existent with the cause of the altered state of the eye requiring the operation. 1507. Besides being free from inflammation, the eye should be otherwise tolerably healthy, at least free from granular con- junctiva, vascular cornea, varicosity, unnatural hardness or softness, dropsy, atrophy, &c. If there is dissolution of the vitreous body, operations through the cornea, like extraction of cataract under the same circumstances, require to be performed with extreme caution, or they may be altogether forbidden. If the inflammation which has caused the state of the eye requiring the artificial pupil has been scrofulous in a child, no operation should in general be attempted, until after puberty. 1508. Prognosis of the operation for artificial pupil. As the eye has in general already suffered so much from inflam- mation, inflammation is apt to be re-excited to such a degree as to occasion failure, or even complete destruction of the eye. This is especially the case, if the inflammation which has ARTIFICIAL PUPIL BY INCISION. 283 caused the state of the eye requiring the artificial pupil has been scrofulous, syphilitic, or gouty. The most promising cases are those in which the condition of the eye requiring the operation, is of traumatic origin, as after operations for cataract, or has been occasioned by purulent ophthalmia. 1509. The amount of vision restored by the operation, de- pends upon the previous state of the eye, and the mode of ope- rating, which that state permitted to be adopted, together with the degree of reaction which follows the operation. The same good vision is seldom or never restored by the operation for arti- ficial pupil, as by the operation for cataract; indeed, it may in general be considered success, if by means of an operation for artificial pupil, sufficient vision be restored to enable the person to move about by himself. 1510. Preparation of the patient for the operation for arti- ficial pupil. In addition to the same general treatment above laid down for the operation for cataract, in order to get the patient into as good a state of general health as possible, the preparation for undergoing the operation for artificial pupil, should consist in bringing the eye into the favourable condition mentioned in ss. 1506-07. 1511. Place of the iris where the artificial pupil should be made.—The artificial pupil should be made, 1st, as near the middle as circumstances of the case will allow. 2d. After the middle, the nasal or temporal side is the next best place ; then the lower, and lastly the upper. 1512.- Position of the patient, assistants, and operator.— This should be the same in general as above recommended for the operations for cataract in general, (ss 1298 et seq.) 1513. The securing of the eyelids also is to be effected in the same way as above recommended, (ss. 1303 et seq.) ARTIFICIAL PUPIL BY INCISION. (Iridotomy.) 1514. There are two principal ways of operating for artificial pupil by incision, viz., through the sclerotica, and through the cornea. An important condition for the success of incision performed either way is, that the larger circle of the iris be still in a healthy state, as regards intimate structure and contractile endowments, so that the opening made in it may, by its retrac- tion, come to gape, and the edges of the incision thus be pre- vented from reuniting. 1515. In the cases which may be the subject of the operation of incision, the closure of the pupil may have been the conse- 284 ARTIFICIAL PUPIL BY INCISION. quence of iritis succeeding an operation for cataract. If the lens is still present but cataractous, it must be divided or displaced in the operation through the sclerotica extracted, if possible, in the operation through the cornea. The same must also be done even if the lens be quite healthy, as wounding it, which would of course be followed by opacity, cannot be avoided in the operation for artificial pupil by incision. It is, Fig. 42. however, to be remarked, that if the lens be still clear, some other operation than incision must if possible be chosen, by which the lens may be preserved untouched. Incision through the sclerotica.* 1516. In this operation, a single incision is made through the iris in a transverse direction, above or below the situation of the natural pupil. The radiating fibres being thus cut across, the edges of the incision retract, and a fusiform opening is the result. The F- .. cases in which this succeeds best, are those in which the closure of the pupil is owing to the iris having been prolapsed through a wound or large ulcerated opening of the cornea, and is thus on the stretch. It will also succeed in simple closed pupil, provided, as above said, the substance of the larger circle of the iris is still quite healthy. There should be a sufficiency of clear cornea, opposite the place where the incision of the iris is made. 1517. The instrument for incision through the sclero- tica.—The instrument used for this purpose, and known under the name of Adams' iris knife, has a blade about nine-tenths of an inch long, about one-twentieth of an inch broad, single-edged, and sharp, but somewhat bel- lied at the point. Fig. 42. 1518. The operation comprehends the following steps:— 1519. First step—Puncturation.—The point of punc- turation is the same as in the operation of reclination of cataract, viz., three-twentieths of an inch from the tem- poral margin of the cornea, and in the line of its trans- verse diameter. * Cheselden's operation for artificial pupil. This was the first operation performed for artificial pupil. The two cases in which Cheselden operated, were cases of closed pupil, after the operation for cataract, by couching. Philosophical Transactions, vol. xxxv. An. 1728. ARTIFICIAL PUPIL BY INCISION. 285 1520. The operator holds the knife, like the straight cataract needle in reclination, its surfaces upwards and downwards, its cutting edge backwards, and rests his hand by the little finger on the patient's cheek, in such a way that the blade of the knife is close in front of the cornea, in a line corresponding to its transverse diameter, and the point extending to nearly opposite the nasal margin. The hand being thus disposed, the thumb and fingers holding the knife are retracted, in order that the point may be applied perpendicularly to the surface of the eye- ball, at the place above mentioned, when it is to be steadily thrust towards the centre of the eyeball, but no deeper than about one-eighth of an inch. 1521. Second step.—The handle of the knife is now to be inclined very much back towards the temple, more than in the operation for cataract, in order that the point of the knife, when pushed on, may come to pierce the iris from behind, near its temporal margin, say one-tenth of an inch, and appear in the anterior chamber. This being effected, the handle of the knife is now to be inclined forward a little, so that when the knife is pushed further on, its point may pass across the anterior cham- ber towards its nasal side. Fig. 43. Fig. 43. 1522. Third step.—Incision of the iris.—By now inclining the handle of the knife still more forwards, so that its edge may be fairly applied against the iris, and then by withdrawing it somewhat, it is made to cut the iris. If by this first stroke, the incision of the iris is not sufficiently large, the knife is to be again pushed on and again withdrawn, its edge being still kept fairly directed against the part of the iris to be cut. This is to be repeated until a sufficiently large incision, at least one-fifth of an inch, has been made. By the contraction of the iris, previously on the stretch, this incision immediately gapes, and that to a considerable degree, and so the fusiform pupil is made. 1523. Incision of the iris being effected, the lens, if still pre- sent, must, whether clear (s. 1515) or cataractous and soft, be divided, in order to its removal by solution and absorption; if cataractous and hard it should be displaced. 1524. In this step of the operation, it may happen, especially 286 ARTIFICIAL PUPIL BY INCISION. if the edge of the knife is unduly pressed back against the iris, that the iris becomes detached from its ciliary connection at some point, most frequently at the nasal side. This will im- pede the completion of the incision to the proper size. The aperture left by the separation may continue open, especially if the iris is healthy in its texture, but more frequently it will close from supervening inflammation. In such a case incision or some other operation through the cornea may be subsequently had recourse to. Incision through the cornea. 1525. The particular modification of this operation usually adopted, is that of Janin, as improved on by Maunoir. It con- sists in making a small section of the cornea, at its lower and outer or its lower part, and by means of Maunoir's scissors in- troduced through the opening, dividing the iris by two incisions divaricating from the situation of the natural pupil, Fig. 44. By this both the circular and radiating fibres of the iris are divided. Modifying this plan, which cannot always be followed, Dr. Mackenzie cuts the radiating fibres only, making the incisions divaricate from a point near the margin of the iris, Fig. 45. In either case, the result of the two incisions is a triangular flap of iris which contracts and shrivels, so as to leave a free opening. Figs. 46, 47. Fig. 44. Fig. 45. . Fig. 46. Fig. 47. 1526. The two incisions in this operation are made when the iris is not on the stretch, and when there is reason to sup- pose that the substance of the iris is not so healthy as to con- tract sufficiently to cause a single incision to gape, and thus to form a pupil which shall remain permanently open. 1527. If the iris were healthy and stretched enough, so that there was reason to suppose that a single incision would gape sufficiently, the operation through the sclerotica is to be pre- ferred,—except when it is intended to extract the lens at the same time, whether cataractous or still clear, or when the cir- cumstances of the case require that the incision for the new pupil should be vertical, as Janin made it, instead of horizontal; it not being easy to make a vertical incision in the iris by the ARTIFICIAL PUPIL BY INCISION. 287 operation through the sclerotica. When a single vertical incision is made, it should be on one or other side of the centre of the iris, in order that the radiating fibres may be cut across. 1528. The instruments re- quired for the operation are an extraction knife and a pair of Maunoir's scissors. The other instruments employed in extrac- tion should also be ready, (s. 1317.) 1529. Maunoir's scissors are extremely fine, when closed, not so thick as a common probe, bent sideways at an obtuse an- gle, the blade corresponding to the convexity, sharp at the point for piercing the iris, the other blade probe-pointed that it may admit of being easily and safe- ly pushed through the anterior chamber. 1530. The operation com- prehends the following steps:— 1531. First step.—Section of the cornea.—This is to be made at the outer and lower part or the lower part of the cornea, as for extraction of the cataract, but to the extent only of about one- fourth of the circumference of the cornea, unless it is contem- plated to extract the lens or an opaque capsule, when the sec- tion should be to the extent of one-third of the circumference. 1532. Second step.—Introduction of the scissors and inci- sion of the iris.—The surgeon introduces the scissors, closed under the flap of the cornea, and when the point has arrived at that part of the iris where the incision is to be commenced, —the situation of the natural pupil or near the margin of the iris according to circumstances,—he opens them, thrusts the sharp-pointed blade through the iris, and pushes them on, the sharp-pointed blade through the posterior chamber, the probe- 288 ARTIFICIAL PUPIL BY EXCISION. pointed blade through the anterior chamber, the iris between them, to the part of the opposite margin of the iris where the incision is to terminate. By now closing the scissors, which should be done sharply, the iris interposed between the blades is cut. 1533. The second incision is now to be made, commencing at the same point as the first, but divaricating from it, (figs. 44, 45.) For this purpose the scissors, still kept closed, are to be withdrawn and re-introduced in the direction in which it is pro- posed to make the second incision. When the point of the scissors is now opposite the commencement of the incision which has just been made, the sharp-pointed blade is passed behind the iris, and the scissors pushed on, then closed, and the incision made as before. 1534. An additional step which may be called for, is extrac- tion of the lens, if present, or of an opaque capsule.* ARTIFICIAL PUPIL BY EXCISION. (Iridectomy.) 1535. There are two principal plans of excision, viz., that of Beer and Gibson, or lateral excision, and that of the first Wen- zel, or central excision. 1536. Lateral excision is the more important, as it is appli- cable to cases in which the lens is transparent, and in which it may and ought to be preserved so. 1537. Central incision is applicable only in cases of closed pupil occurring after the operation for cataract, or combined with cataract. Lateral excision. 1538. Lateral excision is performed by making a small sec- tion of the cornea at some convenient part of its circumference, seizing with a forceps the piece of iris which protrudes, and snipping it off, taking care to include the pupillary margin of that part of the iris. If the iris does not protrude sponta- neously, the portion to be snipped off is drawn out with a blunt hook or the forceps, care being taken not to injure the crys- taline body. 1539. The cases in which lateral excision is applicable are cases of central opacity of the cornea, to such an extent as to * If after the section of the cornea is made, the iris should protrude, ad- vantage is to be taken of this to make a pupil by excision rather than by incision. J ARTIFICIAL PUPIL BY EXCISION. 289 cover the pupil, even when dilated by belladonna, in which the iris and pupil are either natural, or the former, but partially adherent to the cornea, and the latter partially contracted;—the lens being still clear. 1540. The conditions necessary for Fig. 49. Fig. 50. lateral excision are:—1st, a sufficient P extent of clear cornea at that part of its circumference, near where the pupil is to be made, to allow for any opacity which may result from the cicatrice of the corneal incision, and that enough of clear cornea may remain opposite the new pupil; 2d, the iris sufficiently free from adhesions to admit of a portion of it protruding or being drawn out through the corneal incision, in order to be ex- cised. 1541. The eyelids are secured in the same way as in the operation for cata- ract, during the first step or section of the cornea, but during the second step, or excision of the piece of iris, both eye- lids must be secured by the assistant, or one eyelid by one assistant, the other by another, as the operator requires to use both hands. 1542. The instruments required for the operation are:— 1. A cataract-knife for making a small section of the cornea. 2. A fine forceps, fig. 49, or a blunt hook (Tyrrell's hook) fig. 50, for drawing out the piece of iris to be excised, if the iris does not protrude spontaneously; if it does, the forceps is used for lay- ing hold of it. 3. A pair of curved scissors for snipping off the piece of iris, fig. 51. 1543. Lateral excision comprehends the following steps:— 19 290 ARTIFICIAL PUPIL BY EXCISION. 1544. First step.—Puncture or section of the cornea.— This is to be made close to the sclerotica, and to the extent of one-fourth of the circumference of the cornea. 1545. Second step.—Excision of the piece of iris.__The gush of aqueous humours which takes place on completing the section of the cornea will perhaps cause prolapsus of the iris. Fig. 51. 1546. The operator, leaving the eyelids in charge of his as- sistant or assistants, exchanges the knife for the fine forceps and takes the curved scissors in the other hand, holding; them m the manner represented in figure 51, the thumb in one riner the ring-finger in the other, the point of the fore-finger on the joint, the middle finger on the branch in the ring of which the ring-finger is, with their convexity towards the eye, ready for use 1547. If prolapsus of the iris has already spontaneously taken place, it is seized with the forceps, raised up, and a por- tion, including the pupillary margin, snipt off. If the prolapsus ARTIFICIAL PUPIL BY EXCISION. 291 has not taken place, and cannot be made to do so by gentle pressure, the operator carefully introduces the blunt hook, and catching the iris by its pupillary margin, draws it out and snips it off. If the forceps is used for drawing out the iris, it must be made to lay hold of it very cautiously at a little distance from the pupillary margin—close to the junction of the larger with the smaller circle of the iris. 1548. The size of the new pupil should be at least equal to that of the natural pupil in its middle state. As to the quantity of iris to be cut off, in order to obtain a new pupil of this size, it is to be remembered that if the structure of the iris is healthy, even when but a small piece is snipt off, the aperture which results will be of considerable size. 1549. What of the iris may remain protruding is to be gently pressed back with the curette. The eyelids are then to be closed, rubbed over the cornea, and suddenly opened to the light. Central excision. 1550. As performed by Wenzel, this consisted, 1st, in mak- ing a half section of the cornea as for extraction, with the addi- tional manoeuvre of so puncturing and counter-puncturing the iris with the point of the knife in its passage through the ante- rior chamber, that in the act of cutting out, a semicircular flap of the iris was formed. This flap of the iris was then cut off Fig. 52. with a small pair of scissors, introduced through the incision of the cornea. If cataract existed, it was extracted at the same time. 1551. The cases in which Wenzel thus operated, were cases of closed pupil, the lens either having been previously removed by operation, or still remaining but cataractous. Of the opera- tion, however, it is to be observed, that not more is effected by 292 ARTIFICIAL PUPIL BY SEPARATION. it than is or may be by Maunoir's operation by incision, in which the section of the cornea is much smaller. Hence Maunoir's operation is preferable. ARTIFICIAL PUPIL BY SEPARATION. (Iridodialysis.) 1552. This operation consists in detaching the iris from its ciliary connection at some convenient part, and drawing it aside, so as to provide a passage for the light. It may be performed through the sclero- tica or through the cornea. Performed through the cornea, as it now always is, the lens, if clear, may be preserved so. Separation through the cornea. 1553. When the iris is in a healthy state, an opening made by separation, may remain permanent, in consequence of the contraction of the iris, as is shown in cases of accident, in which, by a smart stroke on the eye, the iris has been detached at some part of its ciliary connection. But in the cases in which separation is designedly had recourse to for the purpose of making an artificial pupil, the permanency of the opening cannot in general be calculated on, in consequence of altera- tions in the structure of the iris, produced by the disease which occasioned the necessity for the artificial pupil. 1554. In order, therefore, to ensure the permanency of a new pupil made by separation, the ciliary margin of the detached portion of iris is drawn out through the puncture of the cornea by which the detaching instrument was introduced, and, either left there, to be united in the cicatrice, or cut off. 1555. Cases in which separation is applicable.—Separation is applicable in all cases, but as it is not so good an operation as excision or incision, it is had recourse to in those only in which these two modes of operating are inadmissible. The cases are:— 1556. 1st. Such extensive central opacity of the cornea, that the clear circumferential part is too small to admit of being encroached on by the opacity which might result from the cica- trice of an incision made for lateral excision; or without the clear cornea being so very limited, if it be situated at the upper or nasal side of the cornea, where excision cannot well be per- formed. 1557. In the cases now mentioned, the iris and its connec- ARTIFICIAL PUPIL BY SEPARATION. 293 _u tions being natural, separation is more easy and more success- ful than in the cases next to be mentioned, and, although the new pupil might remain permanent, without strangulating the detached portion of iris in the puncture of the cornea, or cutting it off, it is neverthe- FlS- 54- Eig. 55. less proper, for the sake of certainty, to add the one or other of these acts to the simple separation. 1558. 2d. Extensive central opacity of the cornea and adhesion of the pupillary margin of the iris to it, in which in con- sequence of the narrowness of the circum- ferential portion of cornea remaining clear, the opacity of a cicatrice cannot be risked for Maunoir's operation, and in which not even incision through the sclerotica pro- mises anything, in consequence of the mor- bid state of iris behind the clear part of the cornea, or in consequence of the situation of that part; or when, although incision might be otherwise admissible, the lens is clear, and it is desirable to preserve it so. 1559. As considerable pain attends sepa- ration, the assistant must secure the head well, to prevent any sudden movement by which the operator might be made to de- tach more of the iris than necessary. 1560. Instruments for the operation. 1. Jaeger's keratome, fig. 54, or Beer's cataract-knife. 2. A simple hook,* fig. 55. * Instead of a simple hook, various complex instru- ments have been invented and recommended. Of these the principal are : Reisinger's double hook.—This is composed of two delicate hooks, united like the branches of a for- ceps, and so corresponding with each other in size and direction, that when the instrument is closed like a forceps, the two hooks form but a single one. The instrument thus admits of being used, not only as a double hook, or as a single hook, but also as a forceps. Graefe's coreoncioh.—This consisted originally of a simple hook, provided with a guard which could be slid towards its point, or withdrawn from it, by means of a ferrule on the handle. At the opposite end of the instrument, there was a small knife for 294 ARTIFICIAL PUPIL BY SEPARATION. 1561. The steps of the operation are:— 1st. Puncture of the cornea by which to introduce the hook. 2d. Introduction of the hook, through the puncture of the cornea, into the anterior chamber. 3d. Hooking and detachment of part of the iris. And, 4th. Prolapsus of it through the corneal puncture. 1562. Puncture of the cornea.—This should be about one- tenth of an inch in length; the place where it should be made, which is an important point to determine, depends principally on the part of the iris to be detached, but in some measure also on the state of the cornea, for the incision ought, if possible, to be made at a part of the cornea where there is no adhesion of the iris. 1563. For example, if the iris is to be detached at the nasal side, and the cornea, even though opaque, is free from adhesion to the iris, and admitting of being cut in the middle, the punc- ture may be made there, fig. 56; but if the middle of the cor- nea is not in such a state, then the puncture must be made either above, fig. 57; or below, fig. 58 ; Fig. 56. Fig. 57. Fig. 58. making the opening in the cornea. Graefe afterwards changed the simple hook for a double one made of hardened gold. He also added a spring by which the guard could be carried towards the point of the double hook, which was at the same time closed. Schlagintweit's iriankistron.—This is an instrument very similar to Graefe's simple coreoncion, the principal difference being, that in the former the guard is received by the concavity of the hook, whereas in the latter it meets the point. Langenbeck's coreoncion.—This consists of a silver-tube, like a pencil- case, which serves as the handle, and fixed to one end of it a fine gold tube , about one inch and a quarter long. A steel wire, terminating in a fine hook, is enclosed within the gold tube, and being fixed within the handle of the instrument somewhat as a pencil is in a pencil-case, it admits of being pro- truded by touching a knob on the side of the handle. By means of a spiral spring within the handle, it is again drawn back. In this closed state the concavity of the hook is received by the edge of the golden tube, and its point thus kept so guarded that it is not apt to catch or wound any part by accident. It is to be remarked, that these and analogous instruments, called by different names, are quite unnecessary to the dextrous surgeon, and in the hands of an awkward person are not so manageable as the simple hook or forceps. It is unnecessary to give figures of the instruments. ARTIFICIAL PUPIL BY SEPARATION. 295 Again, if there be nothing limiting the puncture of the cornea to any particular place, but if the new pupil can be obtained only by detachment of the upper or lower part of the iris, then the puncture in the cornea, will require to be made as in fig. 59; or as in fig. 60. Fig. 59. Fig. 60. 1564. The opening in the cornea is made by simple punc- turation with the keratome or cataract-knife, but, at the same time, care is to be taken to make the opening as wide within as without, otherwise the prolapsed piece of iris will not be so readily retained. Another precaution should be to let as little of the aqueous humour escape as possible. 1565. Introduction of the hook.—Having made the incision in the cornea, the operator lays aside the knife for the hook. This he holds, like a cataract needle, and introduces the hook, convexity foremost, and flatways through the opening in the cornea, and in the direction of its axis, into the anterior cham- ber. The hook being fairly in the anterior chamber, the handle of the instrument is to be inclined so far backwards, that its blade may come to be parallel between the iris and cornea. This being arranged, the instrument is to be pushed on through the anterior chamber, the sharp point of the hook being, if any- thing, rather towards the iris than the cornea, to the ciliary cir- cumference of the part of the iris to be detached. Before attaining this point, a little of the extremity of the hook disap- pears behind the margin of the sclerotica. 1566. Hooking and detachment of part of the iris.—Hav- ing thus gained the ciliary circumference of the iris, the handle of the instrument is to be so far rotated and inclined, that the point of the hook may be directed fairly against the iris, and fixed into it, and that as close to the ciliary circumference as possible. 1567. The iris being hooked, the instrument is to be rotated and inclined, so that it may be brought back to the position it was in before the iris was hooked. A steady and sustained, but gentle pull or two is now to be made, until the iris begins to separate. When this takes place the instrument is to be rotated 296 ARTIFICIAL PUPIL BY SEPARATION. half on its axis, so that the iris may be the more securely hooked. If this manoeuvre be attempted before separation has commenced, the iris, being often diminished in the cohesion of its texture, will only be torn, and the hold of it by the hook altogether lost. By now continuing to pull the instrument slowly and steadily, separation goes on. 1568. Prolapse of the separated portion of the iris through the corneal incision.—When the hook arrives with the hooked part of the iris at the puncture in the cornea, some nice mani- pulation is required to bring it out without letting the iris slip away. The essential point is to press back the hp of the cor- neal puncture, which is behind the blade of the hook, in order to make the puncture gape. 1569. As much of the iris at least is to be prolapsed as will suffice to secure its retention in the corneal wound, and as much more as may be necessary to make the new pupil of proper size. In order to the retention of the prolapsed iris, it is to be drawn to one or other end of the puncture, and jammed there between its lips. Fig. 61. 1570. If it be necessary, in order to obtain a proper sized pupil, to draw more of the iris out than is actually necessary for its being retained in the corneal incision, the superabundant part should be cut off. This may happen when the state of the eye has rendered it necessary to make the incision of the cornea nearer the margin where the new pupil is to be, than was above indicated. 1571. When the prolapsed iris cannot be retained between the lips of the corneal incision, somewhat more should be drawn out, and the whole cut off (Iridectomedialysis). 1572. During the detachment of the iris a considerable effu- sion of blood generally takes place into the aqueous chambers. 1573. As the pain is very great, an opiate should be given to the patient after the operation. 1574. If the case in which separation is had recourse to, be complicated with cataract, division or displacement may, ac- DISLOCATION OF THE PUPIL. 297 cording to the nature of the cataract, be performed after reco- very of the eye from the separation. Extraction is not admis- sible ; the state of the eye, which rendered it necessary to have recourse to separation, being in general such as to forbid ex- traction. OPERATIONS FOR AGAIN RENDERING THE NATURAL PUPIL AVAIL- ABLE. Restoration of the pupil to its natural position by abscission. 1575. If the pupil is dragged by a small synechia anterior, from its natural situation to opposite an opaque part of the cornea, and if it appears that were the adhesion destroyed, the pupil would come to be opposite a clear part of the cornea, the operation to be adopted is simply the abscission of the adhe- sion. This is effected by means of a needle cutting on the edges and increasing in thickness. It is passed through the cornea into the anterior chamber slantingly, in order that the aqueous humour may not escape, and the adhesions cut. In doing this, great care should be taken not to injure the lens. Injury to the lens may be readily avoided if the aqueous hu- mour has not been allowed to escape, but not easily if this acci- dent has occurred. Dislocation of the pupil to opposite a clear part of the cornea. (Operation of Adams and Himly.) 1576. This is effected by prolapsing a portion of the iris through a puncture of the cornea, and so dragging the pupil away from the opaque middle part to opposite the still clear circumferential part of the cornea. The puncture of the cornea is made with an iris-knife, or the point of a cataract-knife, close to the sclerotica, and should be about one-tenth of an inch in extent. Through the puncture a blunt hook is introduced, the iris caught by its pupillary margin, drawn out, and left strangu- lated in the opening of the cornea, in order that it may become adherent in the cicatrice. [We have performed this operation by another, and, we conceive, preferable method. This consists in puncturing the cornea with a cataract knife, and then incising that coat to the extent of one-sixth or one-fourth of its circumference, by a rapid cut, so as to cause the sudden evacuation of the aqueous humour. With the gush of this fluid the iris is prolapsed and is strangulated in the wound. If the cataract knife be properly constructed and the incision in the cornea be skillfully made, 298 OPERATIONS FOR ARTIFICIAL PUPIL. this operation will rarely fail, and the danger of wounding the capsule of the lens, with the hook, is obviated. [2d Am. ed. of Lawrence's Treatise on the Eye, p. 455.] 1577. Treatment after operations for artificial pupil.— This should be the same in general as after operations for cata- ract. The patient is to be kept in bed, his eyes protected from the light, cold applied if necessary, and the antiphlogistic regimen observed. 1578. Inflammation generally arises, most frequently inter- nal, sometimes external. According to the form and severity of inflammation, so must be the treatment. 1579. If the lens has been removed, the patient will, of course, require cataract glasses when he comes to use the eye. When the lens is still present, the patient may not require any glass, or he may find his vision assisted either by a concave or by a convex glass. When the new pupil is very much to one side, a slightly convex glass has in several instances been found useful.* INDEX OF THE DIFFERENT MORBID STATES OF THE EYE, IN WHICH VISION MAY BE RESTORED BY THE OPERATION FOR ARTIFICIAL PUPIL, AND OF THE PLAN OF OPERATING, OR MODIFICATION OF IT ADAPTED TO EACH PARTICULAR STATE. STATE OF THE EYE. PLAN OF OPERATION. 1580. Cornea principally af- fected, the iris and pupil either natural, or the iris otherwise healthy in structure, adherent to the cornea, to the degree either of synechia anterior or partial staphyloma, the pupil being more or less dragged and contracted. The lens and cap- sule sound, or the lens not present. 1. Central incurable opacity 1. Dislocation of the pupil, of the cornea, of such a size if the opacity is not very ex- as to cover the pupil, even tensive; but lateral excision, if when dilated by belladonna; more extensive, and if the clear iris and pupil quite natural; part of the cornea be towards lens sound. its outer and lower margin; or * Rau, die Krankheiten, &c, der Regenbogenhaut, vol. ii. p. 215: Bern, 1845. OPERATIONS FOR ARTIFICIAL PUPIL. 299 STATE OF THE EYE. 2. The opacity of the cor- nea not so extensive, but con- traction of the pupil to a greater or less degree, and dragging of it behind the opaque part of the cornea, in consequence of synechia anterior or partial sta- phyloma; the lens sound. 3. Cases in which the pu- pillary margin of the iris is adherent to the cornea, either wholly or to a considerable extent ; the iris, otherwise sound in structure, much on the stretch. PLAN OF OPERATION. separation, if the circumferen- tial clear cornea be very nar- row, and at its nasal side. 2. Reduction of pupil to its natural situation by abscission, if the synechia be small and appears likely to admit of be- ing readily divided. Other- wise, lateral excision, unless the clear portion of cornea be very small or situated towards the inner and upper part, when separation is to be had recourse to. 3. Incision through the scle- rotica, if the lens is no longer present. If, on the contrary, the lens be still present and sound, and if the nasal side of the cornea be that which is the clearest, the operation by sepa- ration should be had recourse to, but if the new pupil admits of being placed opposite the lower and outer part of the cornea, then such a mode of operating as the following, which was recommended by Mr. Tyrrell, may be adopted. He introduced his broad nee- dle, cutting on each edge to the extent of one-fifth of an inch, through the margin of the cornea into the anterior cham- ber, and pierced with it the iris close to its adhesion to the cor- nea, being careful not to pass the point of the instrument backward, for fear of wound- ing the capsule of the lens. Having thus made a very small opening in the iris with the 300 OPERATIONS FOR ARTIFICIAL PUPIL. STATE OF THE EYE. 1581. Iris and pupil affect- ed, cornea sound, lens clear or opaque. 1. Simple closure of the pu- pil from iritis, the lens and cap- sule supposed to be clear. PLAN OF OPERATION. needle, he withdrew it, and then passed the blunt hook into the anterior chamber, and hooked the iris through the opening previously made in it, and gently withdrew the instru- ment. In doing this the iris was usually torn from the point caught with the hook, and such a quantity of the membrane brought through the opening in the cornea by the hook as effected a sufficient aperture in the iris; but sometimes only a fissure resulted. Under such circumstances, Mr. Tyrrell made, after the eye had reco- vered from the first operation, a second opening through the cornea, a little above the cen- tre, and seizing the upper mar- gin of the fissure in the iris with the hook, he drew it to and through the puncture of the cornea, and thus formed a triangular-shaped opening in the iris. " The principal risk in these cases," he remarks, " arises from being obliged to use a pointed instrument to effect an opening in the iris, to permit the passage of the hook, the proximity of the capsule of the lens being so close to the iris, that it is easily injured, when cataract follows."* 1. Lateral excision if possi- ble; if not, separation. * Practical Work, &c, vol. ii. p. 511. OPERATIONS FOR ARTIFICIAL PUPIL. 301 STATE OF THE EYE. 2. Closure of the pupil with cataractous lens, and posterior synechia. PLAN OF OPERATION. 2. If the substance of the iris appears to be healthy, and likely to contract when cut, so as to cause the incision to gape; and if the lens be soft, and fitted for division, incision through the sclerotica with di- vision of the lens. If the lens be hard, and requiring extrac- tion, it will be advisable to per- form Maunoir's operation by incision, and extract the cata- ract through the opening. If the iris is not healthy, separa- tion and subsequent displace- ment of the cataract or central excision with extraction, or the following combination of Mau- noir's operation by incision, with excision of the flap of iris, and extraction of the lens, might be had recourse to. Having made the section of the cornea to the extent of one- third of its circumference, two incisions are to be made in the iris with the scissors; but in- stead of commencing at one point, and divaricating as in the operation above described, they are to commence at dif- ferent points, and made to con- verge and terminate at the same point, thus:— Fig. 62. If the triangular flap thus form- ed does not immediately con- tract and shrivel, it may be 302 CONGENITAL ABSENCE OF THE IRIS. STATE OF THE EYE. 3. Closure of the pupil, after the removal of a cataract. 1582. Partial opacity of the cornea, closed pupil, synechia anterior or posterior, and cata- ract. This is a combination of all the morbid states above enumerated. PLAN OF OPERATION. drawn out of the wound and snipt off. 3. This was the kind of case in which Cheselden perform- ed his operation by incision through the sclerotica; and if the texture of the iris has re- mained tolerably sound, the operation will in general suc- ceed. If the texture of the iris, though not much altered, still appears to have suffered somewhat, it may be advisable to try Maunoir's operation by incision, rather than Chesel- den's; but if the texture of the iris be decidedly altered, then excision or separation must be had recourse to. Except in so far as the situ- ation and extent of the clear part of the cornea on the one hand, and the state of the iris on the other, in such cases, necessitates a modification of plan in operating, what has been said in the preceding pa- ragraphs is here applicable. Section IV.—CONGENITAL DEFECTS OF THE IRIS AND PUPIL. Congenital absence of the iris. (Irideremia congenita.) 1583. The whole iris may be congenitally absent, or there may be still some trace of it (complete or incomplete congeni- tal absence of the iris). 1584. There is a uniform dark, though not the jet black ap- pearance, behind the cornea, but when the light falls upon the COLOBOMA IRIDIS. 303 eye in a certain direction, a dark red reflection from its bottom is observed. 1585. Both eyes have generally been found to suffer from the congenital defect, which in some cases has been complete in the one and incomplete in the other. 1586. Persons affected with absence of the iris do not bear exposure to strong light well, and their vision is imperfect; but, by their habit of keeping the eyebrows depressed and the eye- lids half closed, their eyes are somewhat protected from the too great influx of light, and their vision at the same time rendered more distinct. 1587. The eyes may be in other respects perfectly formed, or they may be the subjects of additional malformations. 1588. Cataract in general sooner or later forms; sometimes it already existed congenitally. It often appears tremulous. 1589. Though cataract exists, the vision is still in some de- gree retained, as the rays of light find a passage to the retina through the zonula lucida, which is seen around the circum* ference of the opaque lens. 1590. In consequence of injury, the greater part of the iris may be detached from its ciliary connection, in which case it shrinks to a small size, and the eye thus comes to appear as if there was incomplete absence of the iris. 1591. Treatment.—The only thing that can be done for cases of congenital absence of the iris is to wear over the eyes, in the manner of spectacles, arched plates of black horn or the like, having transverse slits in them to see through, analogous to the snow eyes of the Esquimaux. If the state of vision require it, concave or convex glasses may be fitted into the slits. 1592. When cataract has formed, and if an operation should be thought advisable, division is the mode of operating to be adopted. Congenital fissure of the iris. (Coloboma iridis congenitum—Irido- schisma.) 1593. The fissure extends from the pupil towards the ciliary circumference of the iris, and its direction is almost constantly downwards. 1594. In some cases the cleft contracts along with the pupil, though slowly; in other Fig. 63. 304 COLOBOMA IRIDIS. cases, the power of contraction appears to be confined to the pupil. 1595. Vision is in general unimpaired. 1596. The fissure usually becomes narrow in approaching the ciliary circumference of the iris, but in some instances the opposite disposition has presented itself. In some cases the fissure has been found to implicate the pupillary edge of the iris merely like an angular notch. Again, a peculiar variety of the defect has been met with, viz., consisting of a fissure in the proper substance of the iris only, whilst the uvea remained perfect. 1597. Sometimes one eye alone is affected with congenital fissure of the iris; sometimes both. A case is on record in which there was this malformation in one eye, and in the other a double pupil, like the figure of 8. 1598. In general, the lower half of the eye is less convex than the upper, and apparently less developed. In some cases the whole eye has appeared smaller than natural, the cornea -fatter, the pigment deficient, and the eyeball oscillatory. In other cases a complication with cataract has been found to exist, but a considerable degree of vision still remained, as the liffh penetrated to the retina through the fissure of the iris, and hence through the zonula lucida by the circumference of the fens. In numerous cases, however, the eyeball has appeared quite natural m other respects, and vision good. in families^6 malformation has been observed to be hereditary 1660. In some cases it has been found on dissection that the coloboma iridis was a part of a more extensive fissure, involving both the retina and choroid. Coupling this with the fact that at a very early period a fissure extends through the ret na'cho roid, and iris, at the lower part, we are readily led to pe cefve that congenital fissure, implicating the lower part of th? iris ™ owing to an arrestment of development. In those cases, how ever m which, as is said, the fissure implicated some other thl the lower part of the iris, the defect cannot be attributed to th's maUcL^ir °f *! idS fr0m injUry (colob°™ iridis trau- maticum) may occur at any part of the iris, and to any extent rhere being usually injury of some other part of th7evebal' the mere fissure of the iris is not the principal part of thTcSe.' 1602. Misplacement of the pupil and deformity of it, are MOVEMENTS OF THE PUPIL. 305 sometimes met with as congenital malformations; as also the existence of more than one pupil, as above noticed (s. 1597). Congenital imperforation of the iris. 1603. In many works on the Diseases of the Eye, persist- ence of the pupillary membrane is alleged as a condition some- times met with requiring an operation for artificial pupil; and as instances, Cheselden's operations are referred to, never any others. Cheselden's operations, however, were not performed in cases of persistent pupillary membrane, but, as above men- tioned (p. 284, note), in cases of closed pupil, after the opera- tion for cataract. 1604. Though the pupillary membrane may sometimes still exist at birth, it ere long disappears, and I believe there is no unequivocal case on record, in which it remained permanent and formed an obstacle to vision requiring the interference of art. CHAPTER IV. Section I.—ABNORMAL STATES OF THE OPTICAL REFRACTIONS AND ADJUSTMENTS OF THE EYE. MYOSIS AND MYDRIASIS. 1605. The name myosis is given to an unnaturally contract- ed, that of mydriasis to an unnaturally dilated state of the pu- pil, persisting in opposition to the influences to which the pupil is ordinarily obedient, and independent of morbid adhesions or other organic change. 1606. To understand the nature of myosis and mydriasis, it is necessary, in the first place, to have a clear conception of the conditions on which the movements of the pupil depend. Conditions on which the movements of the pupil depend. 1607. The pupil is, in dull light, in its medium state, which is about one-fifth of an inch in diameter. It becomes contracted to a smaller size when the light to which the eye is exposed is strong; but, on the contrary, dilated to a larger size when the light is weak. During sleep the pupil is very much contracted. Some time after death it is found of the medium size. 20 306 MOVEMENTS OF THE PUPIL. 1608. When the pupil is of its medium size the iris is in a state of relaxation; contraction of the pupil to a smaller, and dilatation of it to a larger size, are manifestations of an active state of the iris—the former of its circular, the latter of its radi- ating fibres. The contractions of either of these sets of fibres having ceased, it is the elasticity of the iris which brings the pupil back to its medium diameter. 1609. The circular fibres of the iris, by which the pupil is contracted, owe their contractile power to the nerve of the third pair, Avhilst the radiating fibres, by the action of which the pupil is dilated, owe their contractile power to nervous fibres derived from the sympathetic in the neck, and which are com- municated to the ciliary nerves through the medium of the ophthalmic branch of the fifth, and its connections with the carotid plexus. 1610. When the nerve of the third pair is paralyzed, there is fixed dilatation of the pupil, from paralysis of the circular fibres of the iris permitting of unrestrained action of the radi- ating fibres. Besides this effect on the pupil, when the nerve of the third pair is paralyzed, there are ptosis, or falling down of the upper eyelid in consequence of paralysis of the levator palpebrae, permitting of unrestrained action of the orbicularis palpebrarum, and divergent strabismus in consequence of para- lysis of the internal rectus, and other muscles supplied by the third nerve, permitting unrestrained action of the external rectus. 1611. When fixed dilatation of the pupil occurs, unaccom- panied by ptosis and divergent strabismus, it may be owing to paralysis of that branch only of the nerve of the third pair, which goes to the lenticular ganglion; but in many cases— those especially of amaurosis, in which the pupil moves in concert with that of the opposite sound eye—there is no reason for supposing that the third pair is at all affected. The dilata- tion of the pupil is most probably owing to spasmodic contrac- tion of the radiating fibres of the iris overpowering the action of the circular ones. 1612. If this be so, the contraction of the radiating fibres may be supposed to be owing, in the amaurotic cases, to reflex action of the nerves on which the contractile power of the radi- ating fibres depends, called forth by the insensible state of the retina, in a manner analogous to that in which the absence of the excitement by light of the healthy retina calls forth dilatation of the pupil, whilst, in consequence of the same insensible state of the retina, reflex action of the nerves on which the contractile power of the circular fibres depends, is no longer called forth • MOVEMENTS OF THE PUPIL. 307 by the stimulus of light; but in the cases of fixed dilatation of the pupil, in which the retina is quite sensible (mydriasis pro- perly so called), the mode in which the excitement is commu- nicated to the nerves supplying the radiating fibres of the iris must be different. The remote causes are blows on the eye and head, gastric irritation from worms, hardened feces, &c, and these perhaps operate directly through the sympathetic. 1613. By cutting the sympathetic and vagus in the neck in dogs, contraction of the pupil takes place, in consequence of the radiating fibres of the iris being thereby deprived of their supply of nervous influence and paralyzed, whilst the circular fibres of the iris continue in a state of unrestrained contraction. But it is to be observed that as an immediate effect of the sec- tion of the sympathetic, dilatation of the pupil may occur in consequence of the irritation of the nervous fibres, excited at the time by the section. Besides paralysis of the radiating fibres of the iris and consequent contraction of the pupil, para- lysis of the walls of the blood-vessels of the eye is produced: the consequence of which is inflammatory congestion (s. 200). 1614. Persistent contraction of the pupil, apparently in con- sequence of spasmodic action of the circular fibres of the iris, occurs in some cases of amaurosis (erethitic cases). The spasmodic action appears to be kept up by the irritable state of the retina, exciting reflex action of the nerves of the third pair, in a manner similar, except in degree, to what occurs in ordi- nary circumstances by the action of light. In some cases, the spasmodic action appears to be occasioned by irritation of the branches of the ophthalmic of the fifth pair exciting reflex action of the oculo-motor. Perhaps there is, in addition to spasmodic action of the circular, paralysis of the radiating fibres, occa- sioned by antagonistic reflexion on the nerves supplying them. 1615. The motions of the pupil are involuntary. The power of moving the pupil by an act of the will, which some persons possess, is owing, not to a direct voluntary power they have over the iris, but to the circumstance that they can readily exert the voluntary power of adjustment, which calls forth sympa- thetic movements of the pupil, as will be explained below (s. 1636.) 1616. It is not by directly exciting the iris, that light calls forth contraction of the pupil, but by exciting the retina and optic nerve, and thereby determining reflex action of the nerve of the third pair. Hence, Avhen the retina is insensible, or cut off by section of the optic nerve from its connection with the brain, or when the nerve of the third pair is cut off by section 308 MYOSIS. from its connection with the brain, the pupil is not influenced by light, but remains fixed in a dilated state. 1617. In some cases of amaurotic blindness, the motions of the pupil under the influence of light are natural. This is ex- plained by supposing that the morbid condition on which the blindness depends, involves only the part of the brain which is the seat of visual perception, and that it is in front of this part of the brain that that condition of structure exists through which reflection takes place, from the optic on the oculo-motor nerve. 1618. In most cases of amaurosis, motion of the pupil is not excited by the light. If, in a case of this kind, one eye only be affected, the pupil remains fixed, as long as the sound eye is covered, but as soon as the latter is exposed to the light, and motion of its pupil thereby excited, motion of the pupil of the amaurotic eye is generally, though not always, likewise excited. This sympathy between the two irides, which is also manifested in the healthy state by motion of both pupils, though one eye only be exposed to variations of light, is explicable by the fact that the optic nerves have each a root in both sides of the brain, and may therefore each be connected in the manner above ex- plained with both oculo-motor nerves. Myosis. 1619. Myosis may occur uncomplicated with defective sen- sibility of the retina, but as mere contraction of the pupil does not disturb vision much, except in weak light, it does not usually come under the notice of the practitioner. 1620. Myosis, when it comes under the notice of the prac- titioner, is generally attended by defective vision—the myosis and the defective vision being equally symptoms of a morbid condition of the retina. 1621. In those cases in which vision is not impaired, myosis appears to be the result of the habitual contraction of the pupil, induced by constant employment of the eyes on minute and brilliant objects, and is, therefore, frequently met with in jewel- lers, watchmakers, engravers, &c. The circular fibres, from being at first dynamically and temporarily contracted, come at last to be organically and permanently contracted. 1622. In the other cases it appears to be owing to the tonic contraction of the sphincter fibres, in consequence of reflex nervous action, excited by the state of the retina, differing from what is the case in ordinary circumstances only by being long kept up. 1623. Treatment.—In cases of myosis of the first kind, bel- MYOPY AND PRESBYOPY. 309 ladonna has not much effect on the pupil; and in cases of the second kind, when it does produce some degree of dilatation, vision is not improved; but, on the contrary, disturbed by it. The principles which should regulate the treatment of such cases, are the same as those laid down for the cases compre- hended under Amaurosis. Mydriasis. 1624. Mydriasis, unaccompanied by any other disturbance of vision than is accounted for by the state of the pupil, viz., dazzling, confusion, multiplication and coloration of objects, especially near objects, in consequence of diminution of the correction of spherical, chromatic, and distantial aberrations, is to be carefully distinguished from the dilatation of the pupil, which is so common a symptom of amaurosis. 1625. That a case is one of simple mydriasis, is ascertained by requesting the patient to look through an aperture, of the ordinary size of the pupil, in a card blackened on the surface next the eye, when he will be able to see objects quite distinctly. Vision is also improved by convex glasses, and is better in dull light. 1626. Treatment.—The treatment of mydriasis accompany- ing ptosis and divergent strabismus, as the consequence of pa- ralysis of the oculo-motor nerve, is discussed below under that head. Simple uncomplicated mydriasis is sometimes removed by irritating applications to the conjunctiva. But before this local treatment is had recourse, to gastric irritation or other dis- ordered states (s. 1612) of which the mydriasis is likely to be a symptom, should be the object of treatment. MYOPY, OR SHORTSIGHTEDNESS, AND PRESBYOPY, OR FAR- SIGHTEDNESS. 1627. When the distance at which an ordinary sized type can be read comfortably is much less than twelve inches, the vision is said to be myopic; when, on the contrary, it is much greater, vision is said to be presbyopic. Preparatory to entering on an account of myopy and pres- byopy, it will be useful to make some observations on refraction by convergent lenses, and on the adjustment of the eye to dif- ferent distances. 310 ADJUSTMENT OF THE EYE TO DISTANCES. Refraction by convergent lenses and the adjustment of the eye to different distances. 1628.—The rays of light from very distant objects, though not strictly parallel, are usually assumed to be so. The focus to which such rays are brought by a convergent lens, is called the principal focus of the lens. 1629. If rays do not come from such a distant body as to be parallel, but are more or less divergent, then the focus to which they are brought by the lens, is farther off from the lens than its principal focus, viz., at some point between this and infinite distance. This point is nearer the principal focus the more distant the body whence the rays emanated; in other words, the more nearly parallel they are, and vice versa. 1630. The point of an object from which any given pencil of divergent rays emanates, is named the focus of incident rays, and the focus to Avhich these divergent incident rays are brought by the lens is named the focus of refracted rays. These two foci, the focus of incident rays, and the focus of refracted rays, in consequence of the relation between them above pointed out, viz., that when the one is near the other is distant from the lens, are named conjugate foci. 1631. From this it will be perceived, that if the refractive media of the eye were incapable of change, either as regards power, or as regards their relative situation to the retina, the rays of light from objects at one particular distance only, would be collected into foci on the retina. Rays from objects farther from the eye than that distance would come to foci, before ar- riving at the retina, and having crossed, would fall on the retina in circles of dissipation. Rays from objects nearer would not come to foci, except behind the retina, on which therefore they would fall likewise in circles of dissipation. 1632. The result of this would be, that objects could be seen perfectly distinctly only when situated at one particular distance from the eye. But we know that this is not the case. We know that we can see objects perfectly distinctly at differ- ent distances, within certain limits. Hence the eye must admit of adjustment to different distances, like our optical instruments. 1633. Here the distinction is to be explained between per- fect and distinct vision. In perfect vision, the outline, colour and details of the object appear traced with the utmost accuracy, clearness, and strength; and this we have only when the rays of light are brought accurately to foci on the retina. In dis- tinct vision, larger objects are seen so well, that they are readily recognized: the title-page of a book, for example, is readily SHORTSIGHTEDNESS. 311 read, but there is a want of clearness of outline and strength of tint, and small objects or the details of large objects are very imperfectly recognized; this is owing to the rays of light not falling on the retina in foci, but in small circles of dissipation. 1634. The limits within which the eye can see perfectly dis- tinctly at different distances, in other words, the limits of per- fect vision, varies somewhat in different persons, and even in the two eyes of the same person; but in general they may be put down at between nine and fifteen inches. For some dis- tance below nine, or above fifteen inches, the vision may be still distinct, but not perfect. 1635. Though there can be no doubt that the eye is capable of adjustment for vision at different distances, the means by which this is effected have not been unequivocally demon- strated ; still as the power of adjustment is lost with the crys- taline body, it is very probable that it depends on a change in the position and form of the lens. By a very slight movement of the lens forward, and a very slight increase of its curvature, the eye could be adjusted for near distances, and vice versa. 1636. When the eye is adjusted for near objects, the pupil is contracted, and the axes of the eyeballs converged, and vice versa; but these variations in the size of the pupil and direc- tion of the eyeballs, are merely a concomitant and auxiliary, not an essential condition. 1637. It would be out of place here to enter into any further discussion regarding the supposed mechanism by which these changes are effected. Shortsightedness. 1638. This is that state of vision in which, the person can see objects perfectly distinctly only when they are at a very short distance from the eyes, a distance of nine inches or less. 1639. It is owing either to too great refractive power of the refractive media of the eye, or to the distance of the retina be- hind the crystaline being too great; so that in either case, the rays of light come to a focus before arriving at the retina, cross and are in a state of dissipation, when they do impinge on that nervous membrane, and therefore form indistinct and confused images. . . . . 1640. By bringing the object near the eyes, it is distinctly seen, because the rays from it, which enter the eyes, being now more divergent than when it was distant, are not so soon brought to a focus; in other words, the different points of the object as foci of incident rays, and the foci to which these rays 312 SHORTSIGHTEDNESS. are brought in the interior of the eye by the refractive media, are conjugate foci, and accordingly, when the foci of incident rays are brought nearer the refractive media, the foci of refracted rays recede from them. 1641. Too great a refractive power of the media of the eye may be owing either to too great convexity of their curvatures, —the curvatures of the cornea and crystaline,—or too great refractive density, or both conjointly. 1642. The situation of the retina at too great a distance be- hind the crystaline body, may be owing either to a preternatural elongation of the axis of the eyeball, or to the lens being nearer the cornea than usual. 1643. In shortsightedness, the power of adjusting the eye to different distances, is still retained, but within certain limits, thus:—the nearest distance may be from two to four inches, the furthest, from six to twelve. 1644. Appearances presented by the eyes of myopic persons. —In many cases there is nothing peculiar to be observed; but frequently the eyes are prominent and firm, the cornea very convex, the anterior chamber deep, and the pupil dilated. 1645. Peculiarities of the vision of shortsighted people.— 1st. They see small objects more distinctly than other people, because, from their nearness, the objects are vieAved under a larger visual angle. 2d. They see them also with a weaker light, because the objects being near, a greater quantity of rays from them arrive at the eye. Hence, they can read small print with a weak light. 3d. But they can also see more distinctly, and somewhat further off by a strong light than by a weaker one, because the pupil is contracted by the strong light, and all but the more direct rays of light thereby excluded. On the same principle they see at some distance distinctly through a pin-hole in a card; and when they try to view distant objects, they half close their eyelids. The rays of light in these cases have their divergence at the same time somewhat increased by dif- fraction. 4th. They sometimes see objects beyond the limits of their distinct vision, double, or even multiplied. 1646. Subjects of shortsightedness.—This defect of vision seldom occurs in so great a degree before puberty as to be troublesome; when in a great degree in children it may be a symptom of central cataract, (s. 1266.) After puberty, when the eyes come to be used in earnest, shortsightedness is usually SHORTSIGHTEDNESS. 313 first discovered to exist, and it may go on gradually increasing, especially if the person uses his eyes much in reading, and on minute objects ; hence, the greater frequency of shortsightedness i among the educated classes, and those whose occupation is with minute work. Myopy sometimes occurs in old persons, whose vision was previously good for ordinary distances. 1647. Treatment.—To persons whose occupation is with minute objects, shortsightedness, unless in a very great degree, is rather an advantage, as they are enabled to observe all the details of their Avork very accurately; and in the ordinary exercise of vision, the use of concave glasses is a ready and simple help. 1648. When a tendency to shortsightedness manifests itself in young persons, and especially if the future occupation of the person is to be of a kind requiring good vision for distant objects, much exertion of the eyes on minute work should be avoided, and the eyes exercised on large and distant objects. 1649. Concave glasses help the vision of shortsighted per- sons for distant objects, simply by increasing the divergence of the rays of light before they enter the eye, so that they may be less speedily brought to foci than they would otherwise have been, in consequence of the increased refractive power of the media of the eye; or, supposing the refractive power of the media of the eye not increased, but the distance of the retina behind the lens increased, that they may be brought to foci at a greater distance behind the lens than they would otherwise have been, in order to correspond with the greater distance of the retina behind the lens. 1650. Concave glasses are made of different degrees of con- cavity, the shallower being those adapted for the slighter degrees of shortsightedness, the more concave for the greater degrees. 1651. When very shortsighted, a person requires to use concave glasses, not only to be enabled to see distant objects,' but also for reading with, in order to avoid the necessity of stooping. Less shortsighted people use glasses only to be en- abled to see distant objects. 1652. The focal length of the concave glass which a person Avill require to see objects at more than tAvo hundred or three hundred yards distance, should be about equal to the distance at which he can see to read distinctly an ordinary type with the naked eye—six inches for example. 1653. The focal length of the concave glass Avhich a very shortsighted person will require to see to read at a convenient distance, is determined thus:—Suppose he sees to read with 314 FARSIGHTEDNESS. the naked eye at the distance of six inches, and desires to be able to read at the distance of twelve, the one distance is to be multiplied by the other, and the product, seventy-two, divided by the difference betAveen the two distances, viz., six. The quotient tAvelve, is the number of inches the focal length of the glass required should be. 1654. But when a person finds it necessary to have recourse to glasses for shortsightedness, he should go to an optician, and select two or three pairs which appear to assist his vision best; or send for two or three pairs of about the focal length, which, according to the above calculation, he thinks will suit him, and try them leisurely at home for a day or tAvo before fixing his choice on one particular pair. 1655. The folloAving are the circumstances which should guide him in his choice : The glasses should be the lowest power which will enable him to distinguish objects as he wishes, quite readily and clearly, and at the same time comfortably. If they should make objects appear small and very bright, and if in using them the person feel his eyes strained and fatigued, or if he becomes dizzy, and if after putting them aside the vision is obscure, they are not fit for his purpose—they are too concave. 1656. Having once fitted himself, a person should not too hastily change his glasses, although they may appear not to en- able him to see quite so clearly as when he first used them. 1657. A glass to each eye should always be employed; vision is by this clearer, and its exercise less fatiguing to the eyes, than when a glass to one eye only is used. The use of a glass to one eye only is in fact very detrimental, especially to the opposite eye. Farsightedness. 1658. With this state of vision the person can see objects distinctly only when they are at a very considerable distance from the eyes; in reading, for example, he holds the book at arm's length. 1659. Farsightedness being in almost all respects the con- verse of shortsightedness, the best way of discussing it here will be simply to reverse the account above given of shortsightedness, and which will therefore stand thus: 1660. Farsightedness is owing either to diminished refractive power of the refractive media of the eyes, or to the distance of the retina behind the crystaline body being too short; so that in either case the rays of light tend to come to a focus at a point FARSIGHTEDNESS. 315 behind the retina, on which, therefore, they impinge in circles of dissipation, and form indistinct and confused images. 1661. By removing the object from the eyes, it comes to be distinctly seen, because the rays from it which enter the eye, being noAV less divergent than when it Avas near, are more quickly brought to a focus; in other words, the different points of the object as foci of incident rays, and the foci to which these rays are brought in the interior of the eye by the refractive media are conjugate foci; and accordingly, when the foci of incident rays are removed from the refractive media, the foci of refracted rays come nearer them. 1662. Diminished refractive poAver of the media of the eye may be owing to diminution of the convexity of their curvatures, flattening of the cornea and crystaline. As to refractive density, there is probably an increase rather than a diminution of it, but this appears to be more than overbalanced by the diminution of curvature. 1663. The situation of the retina too near the crystaline may be owing either to a preternatural shortening of the axis of the eyeball or a receding of the lens from the cornea. 1664. In farsightedness, the power of adjusting the eye to different distances is much weakened. In this respect far- sightedness differs from shortsightedness, in which the power of adjustment is still retained. In farsightedness it may be said that the habitual adjustment of the eye is for distant objects, and that in trying to read, for example, the power of adjustment is exerted to the utmost, hence the fatigue and confusion of vision which soon ensue. 1665. Appearances presented by the eyes of farsighted peo- ple.__In many cases there is nothing peculiar to be observed; but frequently the eyes are sunk, the cornea flat, and of small diameter, and the pupil contracted. 1666. Peculiarities of vision of far sighted people. 1. They see small objects indistinctly at every distance, because Avhen near, they are out of focus, and Avhen removed from the eye somewhat, they are seen at a small visual angle and with little light. By increasing the light, they see better. Hence, they do not see so well by candle-light as before, and when attempting to read by candle-light, they place perhaps the candle between them and the book held at arm's length. 2. They see large and distant objects very distinctly. 3] In most presbyopic persons, Dr. N. Arnott has ascer- tained that double vision in the eyes singly exists in a slight degree. 1 316 FARSIGHTEDNESS. 1667. Subjects of farsightedness.—Farsightedness seldom occurs except in persons Avho have passed middle age, and in them it is so common, that it is to be vieAved as a natural change in the state of the eye. As it occurs in young persons, it will be spoken of under the head of Asthenopy. 1668. Prevention and treatment.—Though instances have occurred of persons who have been long presbyopic, recovering their former vision, and thereby being enabled to lay aside the use of their spectacles, recovery from presbyopy is not to be calculated on, but this is of small moment, as vision can be so perfectly assisted by means of spectacles. 1669. Something, however, may be done in the Avay of pre- serving the sight by avoiding over-exertion of the eyes in read- ing and other minute work, especially by artificial light, at the time of life Avhen farsightedness, with diminution of adjusting power, usually comes on. 1670. Convex-glasses help the vision of far-sighted people for near objects, by diminishing the divergence of the rays of light before they enter the eye, so that they may be more speed- ily brought to foci than they Avould otherwise have been, in consequence of the diminished refractive power of the eye; or, supposing the refractive power of the eye not diminished, but the distance of the retina behind the lens diminished, that they may be brought to foci at a less distance behind the lens, than they would otherwise have been, in order to correspond with the diminished distance of the retina behind the lens. 1671. Convex-glasses are made of different degrees of con- vexity: the least convex being those adapted for the slighter degrees of farsightedness, the more convex for the greater degrees. 1672. To see distant objects, far-sighted persons do not, in general, require convex-glasses. It is most commonly to enable them to read and do minute work that far-sighted people use spectacles. 1673. If it is only at a very great distance that a person can see distinctly, the focal length of the convex-glass which he will require to enable him to read will be equal to the distance at which he wishes to see to read. 1674. If he is not so very far-sighted, but can see small ob- jects distinctly at twenty inches distance, for example, the focal length of the convex glasses, which he will require to enable him to read at twelve inches distance, is determined by multi- plying the two distances together, and dividing the product, 240, CYLINDRICAL EYE. 317 by the difference between them, viz. 8. The quotient 30, is the focal length in inches of the glasses required. 1675. But when a person finds it necessary to have recourse to glasses for far-sightedness, he should go to an optician, and select two or three pairs Avhich appear to assist his vision best, or send for two or three of about the focal length, which, ac- cording to the above calculation, he thinks will suit him, and try them leisurely at home for a day or tAvo, before fixing his choice on one particular pair. 1676. The following are the circumstances which should guide him in his choice:—The glasses should be of the lowest power which will enable him to see objects distinctly as he wishes, and at the same time comfortably. Glasses which make the objects appear larger than natural, and strain and fatigue the eyes and cause headache, are not adapted to his case—they are too convex. It is usually found that glasses the next degree more convex are required for work by artificial light. 1677. The alteration in the eye on which the far-sightedness depends, generally goes on to increase with age, hence, it is necessary, after a time, a few years, to change the glasses first chosen for others more convex. In regard to this exchange it is to be observed, that it ought not to be too hastily had recourse to, nor, on the other hand, too long delayed. The same feeling of necessity which first prompted to the use of glasses, will indicate the necessity of change. 1678. It is a not uncommon notion that glasses of certain focal lengths are adapted to certain ages, but this is erroneous. Still, though the choice of glasses cannot be determined by the mere age of the person, there is a certain average relation be- tween the age and the focal length of the convex glass required, which is expressed in the following table. Age in years.—40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 100. Focal length in inches.—36, 30, 24, 20, 16, 14, 12, 10, 9, 8, 7, 6. 1679. Reading Glass.—This is a double-convex lens, broad enough to permit both eyes to see through it. It is used for the purpose of magnifying the object; whereas, convex spectacles are used merely to render objects distinct at a given distance, without magnifying them as above mentioned. Cylindrical Eye. 1680. Mr. Airy has written an account* of one of his own * Transactions of the Cambridge Philosophical Society, quoted in the En- cyclopedia Metropolitana, article Light, p. 398, . 359. 318 UNEQUALLY REFRACTIVE STATE OF THE TWO EYES. eyes, which he ascertained to refract the rays to a nearer focus in a vertical than in a horizontal plane. This would take place, he remarks, if the cornea, instead of being a surface of revolu- tion, in which the curvature of all its sections through the axis must be equal, Avere of some other form, in which the curvature in a vertical plane is greater than in a horizontal. This is, in fact, the natural form of the cornea, but in the instance of Mr. Airy's eye, existing, perhaps, in an exaggerated degree so as to disturb vision. 1681. With such unnatural conformation of the eye, a point appears a line of a certain length; a circle an oval; everything being seen elongated in one direction. The cylindrical deform- ation has been met Avith oblique, so that a square appeared a parallelogram. 1682. The defect is remedied by glasses which, to the healthy eye, would make a line of the same length appear a point— Avhich would, in fact, shorten all objects in the same degree and in the same direction, as they are lengthened by the defect- ive eye.* 1683. Each case of cylindrical eye being thus more or less peculiar, lenses must be specially prepared for it; and it is evi- dent that this demands both skill and intelligence on the part of the optician. The general principle on which the glass is shaped, Mr. Ross informs me, is this: one side of the lens is made a portion of a cylinder, of the same diameter as the cy- linder cornea, having its axis, however, placed at right angles to that of the latter. The other side of the lens is made plane, convex, or concave, to suit the condition of the eye irrespective of its cylindricity. Unequally refractive state of the two eyes. 1684. The two eyes may be in different degrees myopic or presbyopic. Though in either of these cases the use of con- cave or convex glasses of a different focal length for each eye is theoretically indicated, it is not in practice found to ansAver. It generally gives rise to such confusion of sight and actual pain that it is soon abandoned. 1685. Again, one eye may be myopic, and the other presby- opic. In this case a concave glass for the former and a convex one for the latter are theoretically indicated, but they are found practically as inefficient as glasses of different focal lengths in the preceding cases. * On the Use and Abuse of Spectacles, by Andrew Ross, Optician, London. DIPLOPY AND POLYOPY AVITH ONE EYE. 319 Loss of power of adjustment. 168/5. The eye may fall into a state in which the vision is neither myopic nor presbyopic, and in which the power of ac- commodation being lost, convex glasses are required to see near objects, and concave glasses to see distant objects. Chromatic vision. 1687. The coloured vision to be noticed here must be dis- tinguished from that dependent on subjective excitement of the retina to be considered below, in Section I. of the next chapter, (ss. 1736, et seq.) 1688. Although the eye, strictly speaking, may not be per- fectly achromatic, it is so in the healthy state to all intents and purposes; but in certain morbid states, its optical parts may become so suffused and deranged as to decompose the light, and make objects appear as if surrounded by the colours of the rainbow, thus: 1st. In puromucous inflammation of the conjunctiva, films of mucus suffusing the cornea give rise to the appearance of irridescence around objects (s. 458). 2d. When there is defective adjustment of the eye, and Avhen, consequently, the rays of light do not fall in foci on the retina, vision, at the same time that it is thus rendered indistinct, and even multiplied, may appear slightly iridescent. Hence iride- scence around objects is seen Avhen the adjusting power of the eye is disturbed by passion, mental abstraction, sleepiness, the action of belladonna, mydriasis. Hence, also, persons who have one eye myopic and the other presbyopic often see colours when they look at very near or very distant objects with both eyes, because one eye only is adjusted to the distance of the object. Diplopy and polyopy with one eye. 1689. In consequence probably of the refractive media of the eye not having perfectly regular curves, diplopy and polyopy with one eye occur, as just mentioned, Avhen the eye is not adjusted to the distance of the object looked at; hence short- sighted people see distant objects, and farsighted people near objects, double or multiplied with one eye as well as iridescent. 1690. But vision of one eye may be double or multiplied independently of defective power of adjustment to distance, in consequence of partial opacity of the cornea, or, more gene- rally, partial opacity of the lens or its capsule. The action of these morbid states is well illustrated by Schemer's experiment, 320 ASTHENOPY, OR WEAKSIGHTEDNESS. which consists in looking at a pin, for example, through two pinholes in a card, placed so close to each other as to be in- cluded Avithin a space equal to the diameter of the pupil. The pin appears double, except when held at a certain distance— that of perfect vision with the naked eye. Asthenopy, or weaksightedness.* 1691. Subjective symptoms.—An incapacity to exercise vision on near objects, as in reading, sewing, and the like, for any length of time. The objects are at first seen distinctly, but the eyes soon become tired and painful—the pain extend- ing to the head—and the vision growing confused. 1692. If the eyes are closed, and rest given to them for a few minutes, vision may be again exercised, but in a short time the eyes will again become fatigued and the vision confused. Both eyes are in general equally affected. 1693. The vision of distant objects is not disturbed, and by the use of convex glasses the exercise of vision on near objects may be much assisted. 1694. Objective symptoms.—The eyes may appear dull and heavy, and are perhaps directed towards objects in a weak in- decisive manner, but in general they present no positive appear- ance of disease. The pupils are quite lively. 1695. Age.—Asthenopy commences in childhood or youth, and may continue throughout life; but it is seldom met with originating in the middle period of life. 1696. State of health.—The subjects of the affection often, but by no means always, labour under general nervous debility —the result sometimes of general disease. 1697. Causes.—There is often no evident cause. A very frequent cause is pure over-exertion of the eyes, as in students, artists, clerks, engravers, watchmakers, tailors, sempstresses, &c, especially by artificial light, together with want of sleep, want of exercise in the open air, &c. The complaint some- times occurs as a sequela of inflammation of the eye, especially scrofulous, external and internal. Injuries of the fifth nerve in the circumorbital region, and affections of the brain, are sometimes followed by asthenopy. Losses of blood, seminal losses, and the like, excite the affection apparently by occasion- ing general nervous debility. 1698. Nature of the complaint.—Asthenopy appears to consist in debility of the apparatus by which the eye is adjusted for the vision of near objects, together with an irritable state of * Mackenzie in Edin. Med. and Surg. Journal, No. 156. ASTHENOPY, OR WEAKSIGHTEDNESS. 321 the retina, connected in some manner with tendency to internal congestion of the eyes. 1699. Diagnosis.—Asthenopy is principally to be distin- guished from presbyopy, night-blindness, and amblyopy, or incomplete amaurosis. 1st. Presbyopy.—Presbyopy sometimes occurs in children, and might be confounded with asthenopy, as the two have this in common, that distant objects are seen without straining of the eyes, whilst in asthenopy during a paroxysm as well as in presbyopy, near objects are not. Presbyopy is, however, dis- tinguished from asthenopy in the circumstance, that by rest the eyes do not acquire the power of distinguishing near objects. 2d. Night-blindness.—Asthenopy is in many cases most troublesome during the use of artificial light, and even approaches to night-blindness in the suddenness of its attacks, and the degree of imperfect vision which attends it. 3d. Amblyopy, or incomplete amaurosis.—In amblyopy there is constantly present an indistinctness of sight extending to all objects large and small, distant and near; in asthenopy indistinctness of sight comes on only after the eyes have been exerted on near objects. In amblyopy the patient sees best after having fixed his eyes for some time on the object he exa- mines ; in asthenopy, on the contrary, vision fails them. 1700. Prognosis.—This is, on the whole, unfavourable, especially if the complaint is of long standing, if it has origi- nated in an ophthalmia, injury of the fifth nerve, or of the en- cephalon. Less unfavourable Avhen it has arisen under other circumstances, provided what appears to be the exciting cause admits of removal. Asthenopy, though it has become con- firmed, rarely passes into amblyopy, and is not likely to end in blindness. 1701. Treatment.—The first thing in the way of treatment is the avoidance, or removal by appropriate means, of any cause which may appear to be in operation, such as over-use of the eyes, seminal losses, &c. 1702. If the complaint appear to have resulted from previous inflammation of the eye, injury of the fifth nerve, or some affection of the brain, an alterative course of treatment with counter-irritation may be tried. 1703. Rest to the eyes, the occasional application to them of the cold douche, good diet, exercise, country air, sea-bathing, and the like, must in general constitute a leading part of the treatment of asthenopy. 1704. When the patient requires to employ his eyes on near 21 322 VISION OF OBJECTS IN AND ON THE EYE. objects, he has no other resource than to use convex glasses, which, in some cases, must be of the very lowest power only; but it would be advisable for the patient, if his occupation re- quires much use of the eyes, to change it if possible for one of an opposite kind. 1705. Complications.—Asthenopy is often complicated with some other affection. It may be complicated with the effects of some one of the ophthalmiae; with myopy or presbyopy; with muscae volitantes; sometimes oscillation of the eyes, and not unfrequently strabismus, with amblyopy or incomplete amaurosis. Persons blind of one eye are not unfrequently affected with asthenopy in the other. One eye may be incom- pletely amaurotic, the other asthenopic. When asthenopy is complicated with amblyopy the vision is at all times more or less obscure, but on reading, &c, it soon becomes still more so, recovering, however, after a little rest. Section II.—VISION OF OBJECTS IN AND ON THE EYE.* 1706. Under certain circumstances, one may see objects in or on his own eyes. The appearance constitutes Avhat is com- monly known by the name of muscae volitantes.^ Under this name, however, certain other morbid appearances are often also included, which are not owing to the visual perception of any object in or on the eye, but are entirely subjective; are owing, for example, to insensible spots of the retina. Such appear- ances as the latter have no real motion, but apparent motion only, depending on that of the eye ; hence they are distinguished by the name of fixed muscae from the former appearances, which present real as well as apparent motions. * Mackenzie, in Edin. Med. and Surg. Journal, No. 164. t Spectra, Scotomata, Myodesopia, &c. COMMON MUSC.E VOLITANTES. 323 A. VISION OF OBJECTS IN THE EYES. Common muscae volitantes. (Floating muscae—Entohyaloid muscae.) 1707. Muscae volitantes ap- Fig. 64. pear to the patient Avho has made no particular examination of them, under the form of blackish motes, or of a thin gray film, like the wing of a fly, or of semi-transparent gray threads, like spiders' web, but if viewed attentively against the clear sky, a Avhite wall, or the like, they are recognized to be made up of appearances such as the following:—1st. A convo- luted string of beads, or a con- voluted transparent tube, con- taining in its interior a row of beads smaller than its diameter, except here and there where one larger than the rest is seen occupying its whole diameter, the end of the string or tube sometimes presenting a dark knobbed extremity, as if formed by an aggregation of the beads composing the string, or contained within the tube (fig. 64, a); 2d. Insulated beads, some of which, and these the more fre- quent, have a well-defined outline (b)—others, and these rarer, have an indistinct outline (c); and, 3d, a parcel of flexuous round watery-looking or spun-glass-like filaments with dark contours, often divided inferiorly into truncated branches (d). 1708. These different appearances may be seen altogether, the beaded appearance on one side of the parcel of watery- looking filaments, and interspersed here and there the insulated beads, one or two of the Avell-defined of which often appearing as if attached to the outside of the beaded tubes; or some one of the appearances may be seen principally or exclusively. 1709. According as the distance of the object against which the muscae volitantes are viewed is greater or less, they appear larger or smaller. 1710. Vision is not affected by floating muscae. Between 324 COMMON MUSC_E VOLITANTES. the several portions of the muscae and by the side of them, the eye still sees everything with perfect distinctness. Even the portions of the retina, over which the shadows which cause the appearance of the muscae fall, are found by the patient, when the corpuscles ascend out of the field of vision, to be perfectly sensible. 1711. Muscae volitantes are often detected suddenly, and thus are supposed to have just occurred. They are most ob- served when the patient looks at the clear sky, a thin cloud, snow on the ground, a white Avail, or the like. They are not, if at all, noticed under the opposite circumstances of a dull light and looking at a dark object. They are not much seen when near objects are looked at. 1712. They are rarely seen in the axis of vision, but gene- rally to one or other side, or above or below. The patient thus seeing them only by a side glance, finds it difficult to fix them in order to study their appearance. They move as the eye moves upwards and dowmvards, or from side to side ; but besides this motion, which, as dependent on that of the eye, is merely apparent, the muscae have a real motion of their own, and still more extensive than their apparent motion. Thus, if, from looking before him in a horizontal direction, the patient suddenly raises his eyes and fixes them on some object above the horizon, he observes that the muscae fly upwards con- siderably beyond that degree of elevation, and even beyond the field of view, and then come sailing down before him till they disappear below. 1713. Besides the motions of ascent and descent, the muscae volitantes under consideration present lateral movements, al- though less marked, as well as changes in the relative positions of their several parts. 1714. Nature of floating muscae.—Hitherto a very common opinion as to the nature of floating muscae has been, that they are subjective sensations, depending on some intrinsic change of state of the optic nervous apparatus, thus confounding them with fixed muscae; but that they are truly objective sensations, occa- sioned by the presence of particles in the interior of the eye, but extrinsic and in front of the retina, throwing their diffracted shadows on the retina, admits of mathematical demonstration. 1715. But without entering minutely into the matter, the proposition may be easily demonstrated thus:—Hold betAveen a convex lens and the white surface on which the image of the light falls, some small object, as a pin. When this is near the lens, its shadoAv is not seen on the white ground, but Avhen it COMMON MUSC.E VOLITANTES. 325 is brought nearer and nearer the white surface, its shadow ap- pears more and more distinctly. 1716. The particles, moreover, appear to be of normal oc- currence in the eye, for the appearance of floating muscae may in general be seen by any person by simply looking through a small aperture in a card at the clear sky, or through the eye- glass of a compound microscope at the flame of a candle two or three feet distant, or simply by bringing the eyelids towards each other, and looking at a lighted candle. 1717. On contemplating the spectra thus brought into view, viz., the beaded filaments, the distinct and indistinctly defined globules, and the watery-like filaments, called by Dr. Macken- zie respectively the pearly spectrum, the distinct insulo-globu- lar spectrum, the indistinct insulo-globular spectrum, and the watery spectrum, it is observed that they are situated in differ- ent planes, one behind the other, " that they never mingle with one another, so as to change the order in which they stand before the eye; but the pearly spectrum always appears the nearest, then the sharply-defined insulo-globular, then the ob- scurely-defined globules, and farthest aAvay the watery threads." 1718. Seat of the particles, the presence of which occasions muscae volitantes. This admits of being mathematically de- monstrated to be in front of the retina, in or behind the vitreous body, but at the same time it appears that it is different for the different kinds, being very near the retina for the pearly spec- trum, and farthest from the retina for the watery spectrum. 1719. Nature of the particles, the presence of which occa- sions floating muscae.—This has not yet been Avith certainty determined. In the vitreous humour (as also in the aqueous) there is contained a great number of corpuscles, most of them resembling lymph corpuscles, though smaller, being between l-4000th and l-5000th of an inch in diameter; but it appears from the calculations of Brewster, Mackenzie, and Ruete, that the size of the particles, the presence of which occasions float- ing muscae, is much greater than this. The corpuscles demon- strable in the vitreous humour are lighter than the fluid itself; in this respect agreeing Avith the corpuscles in the vitreous humour, which occasion muscae volitantes, the latter, as appears from their movements, being lighter than the fluid in which they are suspended. 1720. Muscae volitantes are often seen by persons without any particular notice of them being taken, as they are indistinct, present themselves occasionally only, and are therefore not troublesome. 326 COMMON MUSCJE VOLITANTES. 1721. They are seen most distinctly, and are therefore most troublesome, when there exists an irritable state of the retina, with weakened irradiation, (s. 1743, et seq.) Such a state of the retina may therefore be viewed as the condition on which floating muscae considered as a disease depend. 1722. Dilution of the images of external objects favours, distinctness, on the contrary, prevents the perception of muscae. Hence, when the person is short or farsighted, they appear less evident to him when he uses the glasses fitted to render his vision distinct. This appears to be owing to the stronger im- pression of the external objects making up for the weakened irradiation, so that the weak impression of the objects of the muscae is more readily effaced. 1723. The pupil of an eye affected with muscae volitantes is generally contracted, even when the eye is myopic. 1724. Exciting causes.—Over-use of the eyes on minute objects. Inflammatory diseases of the eyes, external as well as internal. The seeking for them in experiments. Intem- perance. Febrile diseases. Influenza. Disease of the heart. Want of sleep. Dyspepsia. Abdominal congestion. Hys- teria. Hypochondriasis. Morbid sensibility of the system generally, arising from pressure of business, anxiety, and dis- tress of mind. All these causes appear to operate in the same manner, occasioning a congested state of eyes, and weakened irradiation of the retina. 1725. When a hypochondriacal person once detects muscae volitantes, he takes such frequent notice of them that they be- come to him more and more troublesome. 1726. Prognosis.—Though floating muscae may occur along with incipient cataract or amaurosis, they have no connection with either of these complaints. Their occurrence, therefore, is of itself no indication that either cataract or amaurosis is taking place. If, however, there be along with the appearance of muscae a failure of vision, and if that failure be not attributa- ble to myopy or presbyopy, which may be ascertained by a concave or a convex glass not improving vision, then cataract or amaurotic amblyopy may possibly exist. 1727. In uncomplicated cases, the muscae may indeed in- crease in numbers, but very slowly, and never to such an extent as to interfere with the distinctness of vision in any very trou- blesome degree. But sometimes the muscae remain stationary, or even become less. 1728. As they depend on the vision of objects naturally ex- CIRCULATORY SPECTRUM. 327 isting in the eye, in consequence of a morbid sensibility of the retina, whatever tends to promote or relieve this will have the effect of promoting or relieving the muscae. 1729. Treatment.—The removal or abatement of the exciting cause, if it can be detected, is the first thing to be looked to. Rest to the eyes, if they have been overstrained, relaxation from business, quiet to the mind. When the stomach and liver are out of order, mercurial alteratives, followed by tonics, regulated exercise, and change of air. Cold applications to the eyes, such as the cold douche bath (s. Ill) twice or thrice daily for five or ten minutes, is the most important local application. Spectrum of the vascular ramifications and network of the retina. 1730. This may be seen by means of the following experi- ment, Avhich, from having been first pointed out by Professor Purkinje, of Breslau, is commonly called the experiment of Purkinje. It consists in shading, Avithout closing, one eye, and looking straight forward with the other, whilst a lighted candle (the room being otherwise dark) is moved up and down close to the eye on the temporal side. In a short time a magnified spectrum of dark ramifications and anastomoses, on a light ground, appears floating before the eye, moving in a direction opposite to the movements of the candle. J 731. In this experiment those parts of the retina covered by the ramifications of the central vessels not being so much excited by the light as the rest of the membrane, do not retain the impression so long as until the return of the candle; hence the appearance of dark ramifications in the field corresponding to those parts.* Circulatory spectrum. 1732. An appearance of grayish watery-like particles darting in every direction before the eyes, somewhat like the circulation in the web of the frog's foot under the microscope, may be seen by a healthy eye, by gazing at the clear sky for a short time. This appears to be an objective sensation, produced probably * A spectrum of the vessels of the retina is, in certain states of the eye seen independent of external light—light on a dark ground ; but this is owing to pressure on the retina by the vessels. Being thus a subjective phenome- non, it belongs to the head of photopsy.—See next chapter. The appearance above referred to in s. 407 is similar to the vascular spectrum, but is owing to insensibility of the retina, from the pressure and opacity occasioned by the congestion and exudation in inflammation of the vascular layer of the retina. This, therefore, also belongs to the next chapter—to the head oCjixed muscce. 328 PHOTOPSY AND CHROOPSY. by the shadoAvs on the retina of the blood corpuscles circulating in its vascular layer.* B. VISION OF OBJECTS ON THE EYES. Muco-lachrymal muscae. 1733. Sometimes, though rarely, appearances are seen like opaque round spots, surrounded by a halo, which occasionally seem to run together, and again divide, and which slide down- wards, but re-ascend after every nictitation. 1734. These appearances seem to depend on spectra, pro- duced by the layer of mucus and tears, with minute globules of air, on the cornea. They are therefore called by Dr. Mac- kenzie muco-lachrymal muscae volitantes. CHAPTER V. AMAUROTIC AFFECTIONS. Section I.—INTRODUCTION.—ABNORMAL EXCITE- MENT OF VISUAL SENSATIONS. 1735. In amaurotic affections, various visual sensations, though not in themselves unnatural, are apt to be excited un- naturally. As such sensations are important as symptoms, it is necessary to study them; but previously to doing so, the cir- cumstances attending their natural occurrence must in each case be taken into consideration. Sensations of light and colour, independent of external light, excited by internal influences operating on the optic nervous apparatus A 1736. In the unexcited condition of the optic nervous appa- ratus, there is darkness before the eyes, but in the excited con- dition, light and colour are seen. * When one stoops and then suddenly rises, the appearance of showers of lucid globules before the eyes is of a different nature, being a subjective sen- sation, excited by pressure on the retina by the determination of blood. So also is an appearance similar to that above described, except that the particles are lucid. The appearance of lucid spectra, therefore, belongs to the head of photopsy.—See next chapter. t Photopsy and Chroopsy. PHOTOPSY AND CHROOPSY. 329 1737. The agent by which the optic nervous apparatus is usually excited, is the principle of light; but an excited condi- tion, and consequently the sensations of light and colour, may be called forth by other influences, such, for example, as pres- sure. And it is to be observed, that whatever may be the stimulus which excites the optic nervous apparatus, no other sensations than light and colour can be called forth in it. 1738. As nervous primitive fibres are throughout their whole course physiologically the same, it is indifferent what part of the optic nervous apparatus be excited, in order that luminous sensations may be perceived—whether the retina itself be irri- tated, the fibres of the optic nerve in the orbit irritated or cut, or whether the cerebral part of the optic nervous apparatus be pressed on by congestion or tumour. As, moreover, the activity of nervous fibres is always manifested at their peripheral ex- tremities, so in whatever part the optic nervous apparatus be excited, the luminous sensation Avhich results is always referred by the sensorium to the periphery; not only to the periphery, however, but as in natural vision to without the body—(projec- tion outwards). 1739. A familiar example of a luminous spectrum of the kind under consideration is that which, on pressing the eyeball, is seen projected outwards, and on the side opposite to that where the pressure is applied. 1740. Other examples are—a spectrum of the vessels of the retina, light on a dark ground, which, in certain states of the eye, is seen, and which is owing to pressure on the retina by its vessels in a state of congestion ;* the appearance of a shower of lucid globules before the eyes on suddenly rising from a stooping posture, from the disturbance in the circulation in the optic nervous apparatus thereby occasioned. 1741. Analogous appearances of fiery scintillations, flashes of light, and coloured corruscations, occurring spontaneously, are symptoms of irritation or excitement of some part of the optic nervous apparatus—cerebral or ocular,—from inflam- matory congestion; when ocular, from inflammatory congestion of the choroid, as above mentioned (s. 408), rather than from inflammatory congestion of the retina. As such inflammatory congestion may end in amaurosis, so the luminous and coloured spectra are symptoms of incipient amaurosis. They may con- tinue to exist, however, after all visual sensibility is lost. 1742. Sensations of colour of the kind just considered are to * The difference between this and the spectrum in Purkinje's experiment is above explained.—See note, p. 327. 330 IRRADIATION, ETC., OF RETINAL SENSATIONS. be distinguished on the one hand from those which depend on an optical derangement in the eye itself, whereby its achroma- tism is destroyed, (ss. 1687, et seq.,) and on the other from accidental or complementary colours, considered in the next article but one. Reciprocal action of the different parts of the retina on each other's sensations. 1743. Participation of the different parts of the retina in each other's sensations or irradiation of sensations.—Any one fibril of a sensitive nerve may be in action alone. But it is possible for fibrils in a state of activity to communicate a similar state to neighbouring ones. This, which is effected at the central extremities of the fibrils, and of which the result is an extension of the original sensation, is called irradiation of sensations. 1744. The retina is prone to such irradiations of sensations. Thus, if the eye be kept fixed for some time on a small strip of coloured paper, lying on a sheet of Avhite, the strip Avill after a time vanish for a moment. The circumferential part of the retina is more prone to irradiation of sensations than the middle part, but at the entrance of the optic nerve it is most so; in fact, the well known vanishing of images at this part in Mar- riotte's experiment is an exemplification of irradiation. It ap- pears to be owing to irradiation that the spectrum of'the retinal vessels is not in the ordinary exercise of vision seen. 1745. An insensible spot of the retina, if small, may in con- sequence of irradiation not be seen, or at least not constantly seen, as a fixed musca. 1746. On the other hand, weakened irradiation, Avhich is an accompaniment of diminished sensibility of the retina, allows of small insensible spots of the retina to be more readily seen, as fixed muscae; and appears to be the condition on which ocular spectra and complementary colours from retention of retinal sensations to a morbid degree, as well as muscae voli- tantes (s. 1721), depend. 1747. Excitement of opposite conditions in contiguous parts of the retina.—A state of activity of one part of the retina, instead of exciting a similar, may excite an opposite state. Thus, as is Avell known, the brighter the light, the deeper the shadow. Another example is presented by the following expe- riment :—A small strip of gray paper lying on a sheet of red, after the eye has been fixed on it for some time, appears of a green colour, the complementary colour of the red ground. OCULAR SPECTRA, ETC. 331 1748. In accordance Avith this law, an insensible spot of the retina, if large, occasions more distinctly the appearance of a black spot in the field of vision, or a fixed musca, the brighter the light. Spectra consequent to impressions on the retina and comple- mentary colours. 1749. In the natural state, the sensations of the retina remain a short space of time after the impression which occasioned them has ceased to act. Hence, an image of an object may continue to be seen for some seconds after the eyes have been turned aAvay from looking at it. This phenomenon is, in gene- ral, most readily observed in twilight; in daylight the impres- sion of the object on the retina requires to have acted more intensely, and a longer time to produce the effect. 1750. The spectrum appears when the eyes are directed to the sky, projected in the distance and of gigantic size. 1751. The spectrum is seen differently, according as the eyes, when turned away from the object, are darkened or di- rected to an illuminated surface. In the former case, the lights and shadoAvs are the same as appeared at the time of regarding the object; in the latter, they are the reverse. 1752. If the object from Avhich the impression has been derived is coloured, the spectrum is coloured, also, but differ- ently, thus:—If the eye be fixed on a red-coloured object for some time, and then turned away from it, a spectrum of the object will continue to be seen, but instead of a red, of a green colour. If, on the contrary, the object looked at be green, the spectrum will be red; again, if blue, the spectrum will be orange; if orange, the spectrum will be blue; if yellow, the spectrum will be violet; if violet, the spectrum will be yellow. 1753. From this it is seen that the colour of the spectrum is alwavs that Avhich being added to the colour of the object looked at, makes up the sum of the three prismatic colours, yellow, red, and blue, which by their combination form Avhite light; hence, the name comple- mentary which has been given to the colour of the spectrum. 1754. In the annexed figure the primitive colours yellow, red and blue, are placed at the angles of the triangle, the com- pound colours, orange, violet, Orange Yellow Violet Blue Green 332 AMAUROSIS IN ITS VARIOUS DEGREES. and green, at the intermediate points. The primitive colour and the compound one, which thus stand opposed, viz., yellow and violet, red and green, blue and orange, are complementary of each other. 1755. A spectrum is very readily produced, by looking at the setting sun. If, on turning the eyes away they are darkened, the colour of the spectrum is at first luminous Avhite; it then changes to yellow, and from that runs through the different colours of orange, red, violet, blue to black, Avhen the spectrum ceases. If, on the contrary, the eyes are directed to a Avhite surface, the spectrum is at first black, then blue, which colour is succeeded by violet, red, orange, yellow, until the spectrum, becoming white, is no longer distinguished. 1756. In certain morbid states of the retina, even although vision be much impaired, the sensation remains after the impres- sion a much longer time than natural; hence arise illusions of vision from the spectrum and complementary colours. In such a case, for example, if the person, after his eye has rested on some small and near object, the tassel of a blind for example, should accidentally look towards the sky, he will see a magni- fied image of it; but not aware of the cause, he is astonished by what appears to him, a gigantic female-looking figure in the air. Section II.—-IMPAIRMENT AND LOSS OF SENSIBI- LITY OF THE OPTIC NERVOUS APPARATUS, OR AMAUROSIS IN ITS VARIOUS DEGREES. 1757. The sensibility of the retina is greatest in the region of the yellow spot, (not in the situation of the foramen cen- trale,as shown by Herschel,but to one or other side of it.) From thence the sensibility diminishes towards the ora serrata. 1758. In consequence of this, we see only that part of an object very distinctly to which the axes of the eyes are at the moment directed. In examining an object, the axes of the eyes are so moved, that the central region of the retina may be successfully impressed by the rays of light from its different parts. 1759. The difference in the degree of sensibility of the mid- dle and circumferential parts of the retina may be illustrated by a reference to the difference in the degree of sensibility of the TEMPORARY HEMIOPY. 333 skin of the lips for example, and the skin of the cheeks. Whilst the points of the two legs of a pair of compasses, when separated a very short distance from each other, are applied to the skin of the lips, the mind distinguishes the two impres- sions ; but Avhen applied to the skin of the cheek, there is no distinct perception of two points, but a sensation as if one im- pression only were made. 1760. As impressions on the less sensitive skin of the cheek are perceived as if smaller than impressions on the more sen- sitive skin of the lips, so objects seen by the less sensitive circumferential part of the retina appear smaller than when seen by the most sensitive middle part; or, caeteris paribus, an imperfectly illuminated object appears smaller than one brightly illuminated. 1761. In amblyopy, objects appear smaller than natural, owing perhaps to the defective sensibility of the retina (amau- rotic micropy). Temporary hemiopy. 1762. The following is an account of Hemiopy, by Dr. Wollaston, as it occurred in his own person. " I suddenly found, after violent exercise, two or three hours before, that I could see but half the face of a man whom I met; and it was the same with respect to every object I looked at. In attempting to read the name Johnson over a door, I saw only son ; the commencement of the name being wholly obliterated to my view. The loss of sight Avas towards my left, and was the same, Avhether I looked with the right eye or the left. This blindness was not so complete, as to amount to absolute darkness, but Avas a shaded darkness, without definite outline. The complaint was of short duration, and in about a quarter of an hour, might be said to be wholly gone, having receded Avith a gradual motion from the centre of vision ob- liquely upwards towards the left." 1763. More than twenty years subsequently, a similar attack occurred again, without Dr. W. being able to assign any cause whatever, or to connect it with any previous or subsequent in- disposition. " The blindness," says he, " was first observed, as before, on looking at the face of a person I met, whose left eye was to my sight obliterated. My blindness was in this instance the reverse of the former, being to my right (instead of the left) of the spot to which my eyes were directed ; so that I have no reason to suppose it in any manner connected Avith the former affection. * * * On this occasion the affection, after 334 NIGHT-BLINDNESS. having lasted with little alteration for about twenty minutes, was removed suddenly and entirely by the excitement of agree- able news respecting the safe arrival of a friend from a very hazardous enterprise." 1764. Such cases are not uncommon. I have myself twice experienced an attack. The first occurred some years ago in returning from a walk before dinner, one hot day in summer. I felt exhausted, languid, and slightly giddy, but in other re- spects quite well. After dining and drinking a glass of port wine and Avater, the hemiopy became somewhat alleviated, but did not entirely go off until after tea, having continued two or three hours. The second attack occurred some months ago, in consequence of gastric derangement. 1765. In some persons, the affection is of frequent occur- rence, coming on along Avith indigestion, headache and nausea, but going off in a few hours.* 1766. Admitting the doctrine of corresponding parts of the two retinae as modified in the manner explained in the next chapter, and admitting the structural condition of their corre- spondence to be, in addition to semi-decussation of the optic nerves, some continuity betAveen the fibres of the corresponding sides of the retinae, Ave may, with Dr. Wollaston, consider the proximate cause of hemiopy to be some temporary affection of the brain at the origin of one or other optic nerve. 1767. Treatment.—According as hemiopy depends simply on fatigue or gastric derangement, so must the treatment be regulated. Night-blindness.,t 1768. Indistinct vision, recurring regularly at night, is some- times met with as a congenital and habitual infirmity ; there are instances of its having prevailed as an epidemic. Most fre- quently it is met with as an occasional complaint, especially in warm countries and warm latitudes at sea. 1769. In the beginning of the complaint the patient is still able to see objects a short time after sunset, and perhaps to see * The case of a friend of his, which Dr. Wollaston describes, does not appear to be of this kind, but a case of common incomplete amaurosis. The blindness came on after the patient had suffered severe pain in his head for some days, about the left temple, and towards the back of the left eye; his vision became considerably impaired, attended with other symptoms indi- cating a slight compression on the brain. t Caecitas nocturna. The words hemeralopia and nyctalopia have been differently used by authors; some expressing by hemeralopia night-blindness, and by nyctalopia, day-blindness; whilst others have employed the words in an opposite sense. NIGHT-BLINDNESS. 335 a little by clear moonlight, and he can see distinctly by bright candlelight. Vision, however, becomes more and more imper- fect at night, so that after a few days the patient can no longer discriminate the largest objects after sunset or by moonlight, &c.; and after a longer lapse of time, he ceases to see any object distinctly by the brightest candlelight. 1770. The pupils move naturally during the day, but after sunset they become dilated, and contract sluggishly on exposure to light. Sometimes they are considerably dilated, both by day and night. In cases of long duration the pupils are often con- tracted, and there are evident manifestations of intolerance of light. 1771. Causes.—The principal causes of night-blindness appear to be fatigue and exposure to the strong light of the sun and gastric derangement; lunar influence is also considered to operate as a cause. 1772. Congenital night-blindness has been known to affect more than one member of the same family. An instance of this kind has come under my own notice. A most remarkable history of a hereditary night-blindness, which has prevailed in one family for two centuries, has been recorded by M. Cunier.* 1773. Prognosis.—Under proper treatment, the prognosis may be always favourable. The duration of the disease is generally from two weeks to three or six months. If, however, it be neglected or mistreated, vision may become imperfect in the daytime as well as at night. In some cases, the disease has terminated in total blindness. 1774. Europeans who have been once affected with night- blindness, are particularly liable to a recurrence of the com- plaint as long as they remain in tropical climates. 1775,—Treatment.—The remedies to be first had recourse to are those adapted for the removal and alleviation of any general complaint, of which the night-blindness may be symptomatic. If gastric derangement, for example, emetics and purgatives are to be prescribed. If after the removal or alleviation of the gene- ral complaint, the night-blindness has not of itself gone off, a succession of blisters to the temple has been found a most effi- cacious remedy. [Dr. Wharton has cured some cases, simply by excluding the patient from the light. Mercury, turpentine, and cauterizations of the cornea, have been each employed with beneficial results. See 2d Am. ed. of LaAvrence's Treatise on the Diseases of the Eye.] * Annales de la Societe de Medecine de Gand, 1840. 336 FIXED MUSC.E. 1776. In some cases it may be advisable to take blood by cupping or leeches from the neighbourhood of the eye. Dur- ing the treatment the eyes are to be kept shaded, and occa- sionally bathed with cold water. Day-blindness. 1777. The photophobia, which persons accustomed to dark residences, albinos, and children labouring under scrofulous ophthalmia, experience when exposed to strong daylight, does not merit the appellation of day-blindness, understood as the counterpart of night-blindness. In this sense it does not cer- tainly appear that there is any such disease as day-blindness. Fixed Muscae. 1778. These appearances never change their position, either in regard to each other or to the optic axis. Their motion is thus merely apparent, depending on the motion of the eyeball. But it often requires some attention and power of observation on the part of the patient, to distinguish what is real from Avhat is apparent motion. 1779. Fixed muscae vary in number, size, and form. At first semi-transparent, they afterwards become black, or at least dark. They appear in reading, like blotches on the paper, but when the eyes are directed to a distant object, they appear so large that they cover it perhaps. Fixed muscae are most distinct in bright light, in darkness they are not seen. If confined to one eye they are most distinct when the other eye is closed. 1780. Fixed muscae are owing to insensible spots of the retina. The insensible spots are apt to increase in size gradu- ally until the whole retina is overspread with insensibility- total amaurosis. 1781. The spot is sometimes in the centre of the retina, and the appearance seen is that of a dark spot in the middle of the field of vision. This may gradually become broader and broader, until objects are no longer seen, except when situated to a side. 1782. The appearance of a skin with veins in it, above re- ferred to, (s. 407,) differs from the vascular spectrum as seen in Purkinje's experiment, inasmuch as it is owing to insensi- bility of the retina from the pressure and opacity occasioned by the congestion and exudation in inflammation of its vascular layer. It therefore belongs to the present head of fixed muscae. 1783. The insensible spots of the retina on which the ap- pearance of fixed muscae depends, constitute partial amaurosis; their further consideration therefore comes under that head. AMAUROSIS CONSIDERED NOSOLOGICALLY. 337 AMAUROSIS.* Amaurosis considered nosologically. 1784. Amaurosis is impairment or loss of vision from para- lysis of the optic nervous apparatus. 1785. Different degrees of amaurosis.—Amaurosis is said to be incomplete or complete, according as the sensibility for visual impressions is impaired merely, or quite lost; and par- tial or total according as the impairment or loss of sensibility affects a part only, or the whole retina. 1786. In incomplete amaurosis, the patient's field of vision is obscured as if a gauze or cloud were interposed between him and the objects looked at. 1787. In partial amaurosis, the obscurity may involve the centre or the circumference of the field, or some one side only; or it may be limited to a mere spot, or to several spots dispersed throughout the field. Objects are thus seen or not, according to the part of the field of view in which they are situated; or if large enough to occupy the whole field, their circumferential or central part only is seen, or one half only (visus dimidiatus), or a part here and there (visus interruptus). When the insen- sibility is limited to a spot or spots merely, the appearance of fixed muscae is occasioned, (s. 1778, et seq.) 1788. Peculiarities of amaurotic vision.—Vision is often better one day, worse another; sometimes better in the morn- ing, sometimes in the evening; sometimes better after meals, sometimes worse. 1789. The amaurotic person generally sees an object indis- tinctly, until such time as he has steadily fixed his eyes on it, (visus increscens.) Sometimes, however, by moving the ob- ject before him, he sees it better than when at rest. 1790. Objects sometimes appear smaller, (amaurotic mi- cropy,) (ss. 1760-61.) 1791. The patient usually sees better in strong light, but in some cases better in dull light. Sometimes he is intolerant of light, even when the amaurosis is complete. 1792. In some cases the patient sees distant objects better than near; in other cases again, near objects better than distant; and sometimes he sees objects multiplied with one eye, and iridescent: the flame of a candle, for instance, spreading out into rays, and surrounded by coloured halos. * Gutta serena of the Arabians, in contradistinction to gutta opaca, the name they gave to cataract. 22 338 AMAUROSIS CONSIDERED NOSOLOGICALLY. 1793. Subjective visual sensations.—Photopsy, chroopsy, and the undue retention of impressions, giving rise to ocular spectra and accidental colours, are frequent attendants on amau- rosis. The gauze or network seen in the light may still be visible in the dark ; but instead of being gray or black, it is of a silvery or gold colour. 1794. Common subjective sensations.—Uneasy feelings or actual pain in the eye, may or may not have been, or be present. Dryness of the eyes and nostrils is sometimes felt. i795. Double vision, confusion and distortion of objects sometimes occur early in the disease, from some degree of attending strabismus. A similar disturbance of vision may occur without evident strabismus or loss of correspondence of the axes of the eyeballs, but in consequence of loss of corre- spondence of the vertical and horizontal diameters of the eye- balls, from disturbance of the harmonic action of the oblique muscles. The nature of such disturbance of vision is ascer- tained by closing one eye, Avhereupon vision with the other is improved. 1796. Objective symptoms.'—The defective and disturbed vision may be the only symptoms present. There may be no objective symptom, even the staring appearance of the eyes, and their want of power to converge on an object with precision, may be absent in incipient cases. In general, however, there are objective symptoms enough to indicate the nature of the affection, and to confirm the patient's statements.* 1797. The pupil is more or less dilated, and if not quite im- movable, its movements are limited and slow. This, although one of the most characteristic appearances presented by the amaurotic eye, is not constant. In cases in which one eye only is affected, the pupil often moves quite naturally, consenta- neously with the pupil of the healthy eye ; but if this latter eye be covered, whilst the amaurotic eye is examined under the in- fluence of different degrees of light, then the pupil of the amau- rotic eye is found to remain dilated and fixed, uninfluenced by the degree of light. Sometimes again, in complete amaurosis of both eyes, the pupils are as obedient to changes in the degree of light, as in health, (s. 1617.) 1798. Besides the peculiarities of the pupil just considered, there may be deformity of it from greater dilatation towards some one or other side, or even a displacement of the pupil, and the iris may be inclined toAvards the cornea, or its pupillary margin reverted backwards from the cornea. * The general aspect of the amaurotic patient is above sketched, (s. 9.) AMAUROSIS CONSIDERED NOSOLOGICALLY. 339 1799. Sometimes the pupil is much contracted, (s. 1614.) 1800. There is often an appearance as if opacity behind the pupil, deep seated, analogous to the appearance in glaucoma, but pale, and not so well marked. It is to be remarked, however, that this appearance in an equal degree, may sometimes be seen in elderly persons, whose vision is quite good; and on the other hand, numerous cases of amaurosis, and this of the most com- plete kind, present no such appearance of opacity, but a clear black pupil. 1801. In uncomplicated amaurosis, the catoptrical lenticular images are distinct. 1802. Congestion of the conjunctiva, or, on the contrary, great paleness of it, lachrymation or dryness of the eyes, too great hardness, or too great softness of the eyeball, increased prominence, strabismus or paralytic luscitas, and rolling of the eyes, may, in different cases, be accompaniments of amaurosis. 1803. General symptoms.—Symptoms of intracranial dis- ease often attend amaurosis, such as pain in the head, con- stant, intermittent, or periodic, and varying in seat, extent and nature; vertigo, tinnitus aurium, tendency to coma, sleepless- ness, &c. 1804. The digestive organs are sometimes deranged, some- times not. 1805. The pulse may be strong, or weak, or natural. 1806. Such are the principal symptoms which may attend amaurosis. Some, it will be observed, are altogether the con- trary,of others, so that not one alone can be admitted as patho- gnomic, scarcely even the defective vision itself. 1807. These differences in the phenomena depend partly on differences in the nature of the morbid condition on which the paralysis depends, partly on the development of that morbid condition. For the same reason the invasion and progress of the disease differ in different cases. 1808.—Invasion and progress.—The invasion of the amau- rosis may be sudden or gradual. In the former case, vision may be at once wholly lost, or nearly so; in the latter case, it may be only after a time that the vision is seriously impaired. In some cases, the impairment of vision remains at a certain stage Avithout advancing, in other cases it continues to increase, the obscurity thickening and spreading, until the whole field of vision is obliterated to the sense, the perception of light lost, and the amaurosis complete. 1809. Except when the cause is of a purely local nature, both eyes generally become affected; one eye first, perhaps, AMAUROSIS CONSIDERED NOSOLOGICALLY. and by and by the other. The blindness being complete and total in one eye, some degree of vision may be still retained in the other. 1810. Constitution, and previous diseases of the patient.— Amaurotic patients are met with of all constitutions, and are found to have been the subjects of very different diseases, and yet these diseases will often appear to have had some connec- tion, either as cause, or as themselves depending on the same cause with the amaurosis, and may still require to be taken into consideration along Avith the present state of general health of the patient, in determining the kind of treatment to be had re- course to. 1811. The diseases the previous existence of which is often found to have some connection with the amaurosis, either as cause, or as depending themselves on the same cause, are, scrofula, syphilis, gout, rheumatism, dyspepsia, hypochondri- asis, hysteria, apoplexy, epilepsy, paralysis, phrenitis, typhus fever, &c. 1812. In some cases the disease is found to occur in con- nection with disturbed menstruation, pregnancy, hysteria, hemorrhoids, and again to disappear entirely, but again to occur, and then perhaps to remain permanently. 1813. Causes.—The paralysis of the optic nervous appa- ratus, on which amaurosis depends, may be the result of morbid conditions of that apparatus, differing both as regards nature and seat. 1814. As regards nature, they may be congestion or inflam- mation, and its consequences; nervous exhaustion; or pressure by neighbouring parts. As regards seat, this may be in the retina, or the optic nerve, or the cerebral portion of the optic nervous apparatus. 1815. Diagnosis in general.—Amaurosis, in its incipient stage especially, ought to be carefully distinguished, for this is in general the only stage at which treatment is likely to be of much avail. 1816. The affections from which amaurosis requires to be distinguished are principally:—Cataract, mydriasis, myopy, presbyopy, asthenopy, muscae volitantes, night-blindness, glau- coma. See those different articles. 1817. Amaurosis is, however, often complicated with some one or other of these affections. 1818. The distinction of incipient amaurosis from incipient cataract, is of especial importance, as supposing incipient amaurosis mistaken for incipient cataract, it might be allowed AMAUROSIS CONSIDERED PATHOLOGICALLY. 341 to go on unchecked, under the impression that ripening of the cataract was taking place. The patient would thus be deprived of all chance of the benefit which might be derived from treat- ment in rescuing him from irretrievable blindness. 1819. Prognosis.—The prognosis in a decided case of amaurosis is most unfavourable. The disease, when it comes on suddenly, even Avhen complete blindness is present, is not unfrequently relieved or cured, if it has not already existed long. The disease" which has come on gradually, accompanied by pains in the head, is more hopeless in general, as in this case the cause most usually is material disorganization of some part of the optic nervous apparatus; whereas, sudden cases may be OAving to some congestion, extravasation, or exudation, admit- ting of removal by timely treatment. But often, nothing of this can be determined beforehand, to assist the prognosis, or regulate the treatment. 1820. The prognosis is decidedly bad, when the eyeball is either preternaturally hard or soft, or affected with cataract; or if the disease is hereditary, or complicated with epilepsy, para- lysis of some part indicating affection of the brain, &c. 1821. In cases in which one eye only is affected, there is reason to fear for the other. Amaurosis considered pathologically. 1822. Seat of the morbid conditions of which paralysis of the optic nervous apparatus may be the result.—The retina, the optic nerve, or that part of the brain with which the optic nerve is connected, may be together or separately the seat of the morbid condition on Avhich the amaurosis depends. If the retina only be affected, it cannot receive the impression which should be transmitted by the optic nerve to the brain;—if the optic nerve only be affected, it cannot transmit the visual im- pression from the retina to the brain;—if that part of the brain with which the optic nerve is connected, be alone affected, the sensorial poAver to take cognizance of the visual impressions transmitted by the optic nerve is lost. 1823. Thus, the general result is the same, whether the different parts of the optic nervous apparatus be affected to- gether or separately. NotAvithstanding this, it is of importance practically to determine as accurately as possible the seat of the morbid condition, on which the loss of vision in any given case depends. . 1824. Nature of the morbid conditions oj which paralysis of the optic nervous apparatus may be the result.—In the first 342 AMAUROSIS CONSIDERED PATHOLOGICALLY. place, it is to be observed, that paralysis of the optic nervous apparatus, like paralysis of other parts of the nervous system, may occur without any morbid condition, the nature of which is appreciable, either by particular symptoms during life or by anatomical examination after death. Generally, however, there are symptoms and other circumstances of the case during life, or appearances after death, sufficient to account for the paralysis. In regard to appearances after death, however, it is to be ob- served that many of the morbid conditions in which the optic nervous apparatus has been found in cases of amaurosis, though of themselves very efficient causes of paralysis, and irreme- diable, are not to be viewed as standing in the relation of original cause of the paralysis, but rather as the effect or, at the least, as the coincident effect of the morbid condition which was the immediate cause of the paralysis. To such morbid conditions may be referred, hardening or softening of the brain, of the optic nerve or retina, atrophy, thickening or optic en- largement (which may be followed by atrophy). 1825. The morbid conditions, acting as the immediate cause of paralysis of the optic nervous apparatus in amaurosis, are in their nature essentially the same as those which act as the immediate cause of paralysis of other parts of the nervous sys- tem, and may be referred to the two principal heads of intrinsic and extrinsic. 1826. Intrinsic morbid conditions of the optic nervous ap- paratus acting as causes of its paralysis in amaurosis.— These may be at first inflammation or simple congestion of some part or the whole optic nervous apparatus, and as effects of this, exudation of serum or lymph, or extravasation of blood. Or the opposite condition of a defective supply of blood to the parts followed by marasmus. 1827. These morbid conditions, it is to be observed, may not be confined to the optic nervous apparatus, but extend to the brain generally, in which case the amaurosis will form a point of inferior consideration. 1828. Morbid conditions extrinsic of the optic nervous ap- paratus acting as causes of its paralysis in amaurosis.— These operate by pressure on the optic nervous apparatus. To them belong abscesses of the brain, hydrocephalic collec- tions, tumours, &c. of the brain or its membranes, aneurismal affections of the cerebral or ophthalmic arteries, exostosis, &c. of the bones of the cranium or orbit, abscesses in the orbit, tumours in the orhit, or in the neighbouring cavities and sinuses of the skull or face, affections within the eyeball, as inflam- AMAUROSIS CONSIDERED PATHOLOGICALLY. 343 mation of the choroid, hydrophthalmic collections, and the like. 1829. Eventually the pressure may produce organic change of the optic nervous apparatus. 1830. It will be observed that many of these morbid con- ditions are of such grave importance in themselves, that the amaurosis produced by them forms but a secondary considera- tion in the case. 1831. Both intrinsic and extrinsic morbid conditions of para- lysis in amaurosis may coexist. Examples readily suggest themselves. To take one from the eyeball, besides inflamma- tory or simple congestion of the retina, there may be a similar state of the choroid producing pressure on the retina. 1832. Morbid conditions of the retina on which the para- lysis in amaurosis may depend.—Intrinsic.—Vascular conges- tion of the retina or choroid, or both, simple or inflammatory, acute or chronic, and, as the consequence of it, degeneration of the structure of the retina, (see Posterior Internal Ophthalmia,) thickening, atrophy, softening, adhesion between the retina and choroid, &c. Injuries, whether direct wounds, or the lesion, whatever its nature may be, produced by concussion, or by a sudden glare of intense light, or by over-exertion of vision. 1833. Extrinsic, but still seated within the eyeball.—In- flammation or congestion of the choroid and its consequences. Subsclerotic dropsy, subchoroid dropsy, vitreous dropsy, he- mophthalmus, displaced lens. Inflammation of the choroid may thus act, both by producing disorganization of the retina, and giving rise to pressure on it. 1834. The morbid conditions extrinsic to the retina and seated without the eyeball, are, for the most part, the same as the extrinsic morbid conditions to Avhich the orbital portion of the optic nerve is subjected. 1835. Morbid conditions of the optic nerve on which the paralysis in amaurosis may depend.—Intrinsic.—Direct in- jury of the optic nerve.—Congestion, simple or inflammatory, and as effects, general or partial induration or atrophy,—thick- ening of the sheath and exudation between it and the nerve. Tumours attached to or contained within the sheath or involving the substance of the optic nerve, including medullary or me- lanotic disease. Aneurismal enlargement of the central artery of the retina while within the optic nerve. Extravasation of blood in the same place. 1836. Extrinsic.—These necessarily come under two sepa- 344 AMAUROSIS CONSIDERED THERAPEUTICALLY. rate heads, viz., those to Avhich the orbital, and those to which the intracranial portion of the optic nerve is subjected. 1837. The latter will come under the more general head of extrinsic morbid conditions affecting the intracranial portion of the optic nervous apparatus ; the former therefore alone fall to be enumerated here. 1838. Inflammation and abscess in the orbit; exostosis of the orbital bones; tumours in the orbit or neighbouring cavities ; fractures of the anterior part of the base of the skull or of the orbit. 1839. Morbid conditions of the intracranial portion of the optic nervous apparatus on which the paralysis in amaurosis may depend.—Intrinsic.—Injuries — concussion, laceration; congestion—simple or inflammatory, and its effects, hardening or softening, hypertrophy or atrophy, abscess, &c.; apoplexy; scrofulous tubercles; tumours of different kinds ; hydatids. 1840. These morbid conditions may implicate other parts of the brain at the same time. 1841. Extrinsic.—Fracture of the cranium with depression or extravasation of blood in the situation of the intracranial portion of the optic nervous apparatus ; exostosis of the bones of the cranium in the same situation; tumours of the dura mater; inflammation of the membranes of the brain, and its consequences, adhesions, thickenings, depositions of serum, lymph, pus, &c.; hydrocephalus, superficial or ventricular; tumours of the brain, implicating the optic nervous apparatus by pressure, such as enlarged pituitary, or pineal gland ; aneu- rism of one of the encephalic arteries. 1842. Of these different morbid conditions, it is to be ob- served, that many of them are well marked and recognized forms of disease in the pathological sense, the amaurosis being at once recognizable as a symptom merely. Others, again, are not so recognizable during life, and the blindness being the prominent symptom, the case is said to be one of amaurosis in the nosological sense. 1843. Causes of the different morbid conditions of the optic nervous apparatus in amaurosis.—These may be said to comprehend the remote causes of disease in general, in addition to such as act on the eyes in particular. Amaurosis considered therapeutically. 1844. The nature of the morbid condition on which the amaurosis depends, and the causes Avhich may have excited that morbid condition, are points which must be ascertained AMAUROSIS CONSIDERED THERAPEUTICALLY. 345 before any rational mode of treatment can be determined on. In numerous cases, however, it must be confessed that these points cannot be satisfactorily ascertained; the treatment adopted must, therefore, be partly empirical and partly founded on gene- ral indications. 1845. The different morbid conditions on which amaurosis may originally and essentially depend are, it has been above seen, referable to the three folloAving principal heads :— 1. Congestion of the optic nervous apparatus and its effects. 2. Exhaustion of the optic nervous apparatus. 3. Pressure on some part of the optic nervous apparatus. 1846. These conditions, however, it is to be observed, may be more or less mixed up with each other, or one may super- vene on the other; hence, according as one or other appears to be in operation at the time, so must be the treatment. 1847. Amaurosis from congestion of the optic nervous ap- paratus.—The disturbance of vision consists at first of the appearance of a thick gauze or mist, stretched between objects and the patient; increased after meals, or in consequence of any bodily effort or mental excitement. This goes on increas- ing until the amaurosis is total. 1848. The dimness of vision is ushered in, and accompanied by intolerance of light, photopsy, and chroopsy. 1849. The patient has a feeling of distention of the eyeballs, as if they were increased in size. 1850. The pupil is at first contracted and sluggish; eventually it becomes dilated. The contracted state of the pupil appears to be owing to the irritation of the optic nervous apparatus, exciting the action of the nerves governing the contraction of the pupil—reflex action being as yet unimpaired ; but subse- quently, when the retina becomes insensible, reflex action is arrested, and the pupil becomes dilated. 1851. The iris inclines towards the cornea in consequence of the fullness of the eyeball, Avhich is hard and sensible to the touch, and perhaps unduly prominent. The conjunctiva is at the same time somewhat injected. 1852. In addition to the state of vision and of the eye now described, there are symptoms of cerebral congestion, head- ache, giddiness, restlessness, or sleepiness, with flushed face, hot skin, and throbbing of the arteries of the head. 1853. The robust and the feeble may be equally the sub- jects of this form of amaurosis. It is most common in middle age. 1854. The causes to which congestive amaurosis has been 346 AMAUROSIS CONSIDERED THERAPEUTICALLY. attributed are very various. Exposure of the eyes to strong heat and light in those who work before large fires, &c. Over- exertion of the sight. Forced exertions of the body while stooping the head, especially in plethoric or drunken persons. Pregnancy. Sudden suppression of discharges—the menstrual, perspiratory, hemorrhoidal, purulent, &c. Gastro-hepatic, or gastro-intestinal irritation, as in dyspepsia, scybala, worms. Irritation of the nerve of the fifth pair. Passions of the mind. Fevers. Organic disease of the heart. 1855. Prognosis and treatment. The cases of amaurosis under consideration, if early seen, are in general those in which treatment may be undertaken with most hope of advantage, provided—and this is the first point to which attention must be directed—the causes just enumerated can be avoided, removed, or mitigated. 1856. The plan of treatment is, first, the general antiphlo- gistic plan above described (s. 421 et seq.), consisting principally of bleeding and mercurialization, and afterwards the tonic and alterative, together with counter-irritation (s. 440). 1857. If the disease has already fallen into a torpid and chronic state, the tonic and alterative plan of treatment, with counter-irritation, may be the only one admissible. 1858. Amaurosis from exhaustion of the optic nervous ap- paratus.—The blindness is at first incomplete and partial. A gray cloud or network, flickering before the eyes in some one direction, only gradually spreading and increasing until the whole field of vision be obscured. Vision is improved after meals, and in consequence of any agreeable excitement, but rendered worse under the opposite circumstances. 1859. Vision is better in bright light; therefore the blindness may simulate night-blindness. There is no photopsy, nor any complaint of fullness or pain in the eyes. 1860. The pupils are generally dilated and sluggish, or im- movable ; the conjunctiva blanched; the face pallid. 1861. The subjects of this form of amaurosis are generally of an age between puberty and middle life. 1862. Exhaustion of the optic nervous apparatus is often a mere accompaniment of general nervous exhaustion, arising from great loss of blood, or excessive discharge of secretion, as in protracted suckling, seminal losses, especially by onanism, or arising from grief and other depressing passions—from low nervous fevers, fright, &c. 1863. Prognosis and treatment.—In the cases depending AMAUROSIS CONSIDERED THERAPEUTICALLY. 347 on exhaustion of the nervous system, the prognosis is much less favourable than in those depending on congestion. 1864. The plan of treatment fitted for them is the tonic and alterative, (ss. 440-41,) with counter-irritation, in prolonged courses. 1865. It is in this form of amaurosis that strychnia and veratria, endermically applied,* have been much recommended; but their efficacy has not been satisfactorily established. The same must be said of electricity and galvanism, and stimulating vapours to the eyes. 1866. The amauroses which arise from super-excitation occasioned by sudden strong impressions on the retina, such as an intense glare of light falling on the eye, concussion of the eyeball, or a stroke of lightning, and also those arising from overplying vision, appear to depend partly on nervous exhaustion, and partly on congestion. For example, the spot of the retina acted on by a sudden glare of light, or by smart concussion from a blow, is at once rendered insensible, and the result is a fixed musca, which may ultimately go away or re- main ; or the whole retina may become insensible, though this more generally takes place slowly, as a consequence of super- vening congestion or inflammation. 1867. In such a case the treatment should be the same as for congestive amaurosis. 1868. Amaurosis resulting from pressure on some part of the optic nervous apparatus.—In the cases of amaurosis result- ing from pressure on some part of the optic nervous apparatus, by extravasation of blood, tumours, collections of fluid, &c, the extent and degree of blindness, and of the accompanying subjective visual sensations, differ according to circumstances. 1869. In many such cases the amaurosis is but a secondary consideration, more pressing symptoms of the organic disease being present; in other cases the amaurosis may be the only or principal appreciable symptom. 1870. To this head belongs apoplexy of the eyes, which sometimes occurs suddenly, in consequence of violent exertion. * Strychnia is usually applied by sprinkling it daily on the raw surface, left by a blister, on the temple, or over the eyebrows, to the quantity of one- eighth or one-half grain at first. This quantity may be gradually increased to as much as two grains; but if spasmodic twitchings occur, the use of the remedy must be intermitted. Veratria is employed in the same quantities as strychnia, but generally in the form of ointment, (gr. v—xxx to^i of axunge,) rubbed over the eyebrows, or on the temples. 348 GLAUCOMA. With general determination of blood to the head, the conjunc- tiva is found congested, the eyeballs tense, and the pupils dilated and fixed. There may or may not be detected an ap- pearance of extravasated blood in the interior of the eye. 1871. Prognosis and treatment.—Except when the cause of pressure is seated in the orbit or in the eye, and is remov- able by operation, any treatment adopted must be regulated according as the general symptoms agree with one or other of the preceding forms, consisting, in the one case, of blood-letting and mercurialization, in the other of tonics, alteratives, and counter-irritation. When, as is often the case, it cannot be determined what is the nature of the cause of pressure, or even that the case is one of pressure, the treatment must still be regulated by the same principles. 1872. Amaurosis from apoplexy of the eyes, in general rea- dily yields to the treatment above indicated for congestive amau- rosis, (s. 1856.) Section III.—GLAUCOMA AND CAT'S EYE. GLAUCOMA. 1873. Glaucoma is a name applied to a peculiar greenish opaque appearance, deep behind the pupil, changing its seat according to the direction in which the light is admitted, being always most concentrated on the side opposite the light. This appearance occurs in very different degrees, from a greenish reflection barely discernible to a grass-green opacity. 1874. Hippocrates and the ancient Greeks comprehended under the name of glaucoma every kind of opacity which ap- pears behind the pupil. The later Greeks, as Rufus, Galen, Paul of Egina, and others, however, restricted the term to the incurable opacities behind the pupil, while to the curable, they gave the name of hypochyma;—the former they supposed to be a disease of the lens, the latter to be a concretion in front of the lens. 1875. Brisseau* appears to have been the first Avho gave out the opinion, that while cataract, as first shown by Rolfink, Borel, and others, is an opacity of the crystaline body, glaucoma is an opacity of the vitreous. * Traite de la cataracte et du glaucome, Paris, 1709. GLAUCOMA. 349 1876. By some the appearance of glaucoma has been sup- posed to be owing to reflection from the bottom of the eye, in consequence of the morbid state of the retina and choroid, Avith loss of pigment, Avhich often exists in glaucoma. 1877. It was, however, satisfactorily demonstrated by Dr. Mackenzie, in 1828, that the cause of the glaucomatous ap- pearance resides in the lens.* 1878. The change in the state of the lens, on which the glaucomatous appearance depends, consists in its having be- come, especially in its central part or kernel, coloured more or less deep amber Avhen viewed by transmitted light, green when vieAved by reflected light. The lens usually retains its transpa- rency unimpaired, except in so far as the depth of colour inter- feres with it, but it may become at the same time more or less opaque. 1879. The proofs adduced by Dr. Mackenzie that the cause of the glaucomatous appearance resides in the lens, are the fol- loAving :— 1. On removing the lens by operation from a glaucomatous eye, the pupil no longer presents the glaucomatous colour, but appears black, as natural. 2. On dissection of glaucomatous eyes, he found the lens, especially its central part or nucleus, of a yelloAV, amber, yel- loAvish-red, or reddish-brown colour, when viewed by trans- mitted light; greenish when viewed by reflected light. 1880. In demonstration of the different degrees of opacity of the lens Avhich may exist in the different stages of glaucoma, Dr. Mackenzie Avas the first to apply the catoptrical test (s. 1240, No. 13, 14). 1881. Along with a glaucomatous appearance behind the pupil, vision may still be good, or it may be defective or totally lost. In the latter case, the defective vision may be owing in part to the deeply-coloured nucleus of the lens intercepting the rays of light in the manner of cataract, or to actual cataractous opacity co-existing, but in most cases it is OAving to complica- tion with insensibility of the retina. 1882. From this it may be inferred, that the glaucomatous state of' the lens occurs in diseased states of the eye, essen- * M. Sichel, of Paris, has lately laid claim to this discovery but even ac- r-nrdi™ to his own showing, his observations date only as far back as 1831, wIereaVDr'MaSrenzie's JSre recorded twice before.that^.t» jj .„ rst in 1828, in the Glasgow Medical Journal, and again in 1830 in the 1st edition of his Practical Treatise. 350 GLAUCOMA. tially different from one another. Hence, if we take glaucoma as a genus, the principal species are as follows:— 1. Simple glaucoma. 2. Glaucoma with cataract. 3. Chronic glaucoma with amaurosis. 4. Chronic glaucoma with amaurosis and cataract. 5. Acute glaucoma with amaurosis. Simple glaucoma. 1883. Here we have the glaucomatous appearance behind the pupil, but the eye, in other respects, appears quite healthy, —the cornea clear, the pupil lively, the consistence of the eye- ball normal, and vision—with the exception that it may be pres- byopic or myopic,—good. 1884. Simple glaucoma is of frequent occurrence in old people. It continues for life, but does not necessarily become complicated either with cataract or amaurosis. Simple glaucoma with cataract.* 1885. In this species of glaucoma, the green reflection from the glaucomatous nucleus of the lens, is seen somewhat ob- scured by the cataractous whiteness of the surface. The retina is sound, but, as is usual at the advanced period of life Avhen this species of cataract occurs, the vitreous body is more or less dissolved. 1886. This form of glaucoma does not essentially differ from the kind of hard cataract above noticed, (s. 1224.) 1887. Treatment.—As was first pointed out by Dr. Mac- kenzie in 1828, the operation for cataract may be performed with success in cases of simple glaucoma with cataract.t But this is the only species of glaucoma in which an operation for the removal of the lens is admissible. The operation may be by extraction or reclination, according to the circumstances of the case, (ss. 1310, 11.) Chronic glaucoma with amaurosis. 1888. This, which is the species of glaucoma generally taken as the type of the disease, is identical with chronic ar- thritic posterior internal ophthalmia, (s. 891, et seq.) 1889. The eyeball is hard to the touch from dissolution of * Simple glaucomatous cataract—green cataract in the limited acceptation. t M. Sichel claims having first pointed out this also; but with no greater justice than in the case of the discovery that the glaucomatous colour behind the pupil is owing to the state of the lens. GLAUCOMA. 351 the hyaloid, and superabundance of vitreous humour. The sclerotica is attenuated and dark-looking; the Avhite of the eye pervaded by varicose vessels ; the cornea often slightly nebu- lous and rough; the iris pale and inclined toAvards the cornea; the pupil, at first limited and sluggish in its motions, becomes dilated—generally ovally dilated—and fixed; the peculiar glau- comatous appearance behind the pupil well marked. 1890. Vision is impaired or lost. 1891. In addition to the defective vision, there are muscae and fiery and coloured spectra before the eyes, and not unfre- quently more or less severe pain in the forehead, supra-orbital regions, temples or face, of a rheumatic or gouty character. 1892. Both eyes are usually affected, but one may be less so than the other. 1893. The characters above given (s. 1240), as distinguish- ing glaucoma from cataract, are those of this form of glaucoma. 1894. The disease is incurable. Chronic glaucoma with amaurosis and cataract.* 1895. This is an advanced stage of the preceding form of glaucoma. The eye is now quite insensible to light, but pho- topsia and pains around the orbit may continue. 1896. The pupillary margin of the iris is perhaps retro- verted, and the lens, now become cataractous in its external substance and hypertrophied, protrudes through the dilated pupil into the anterior chamber, and even comes to press on the cornea. The cornea may in consequence ulcerate, and the lens be evacuated with hemorrhage. Eventually the eye becomes atropic and quiet. Acute glaucoma with amaurosis. 1897. This is identical with acute arthritic posterior internal ophthalmia above described, (s. 891, et seq.)t * Cataracta glaucomatosa, of Beer. tDr Mackenzie admits two other species of glaucoma. The one which he call's opalescent glaucoma, he formerly described in his Practical Treatise, ?n 777 3d edit.,) as one form of cat's eye. The glaucomatous appearance, which i's seen only when the eye is viewed obliquely, and seems as if pro- duced by the reflection of light from the front of the crystahne capsule,-pre- sents a close resemblance to the reflection from a piece of opal. When the eve is viewed in front, the appearance behind the pupil is merely that of a brownish opacity. Disturbance of vision may or may not co-ex.st. The othlr species he calls traumatic glaucoma having met w.th it as a consequence ./penetrating wounds of the eye. The pup.l is contracted and frrejular; and, behind it, the glaucomatous appearance is seen of an emerald green colour. The exact seat of this appearance he has not yet been able to determine. Vision is irrecoverably lost. 352 sensations of the two eyes. cat's eve. 1898. This term has been applied to cases of amaurosis, in which there is a reflection from the bottom of the eye similar to that in the cat; but the appearance is by no means charac- teristic of any one disease of the eye. 1899. Beer, who introduced the term, and who describes cat's eye as the type of his second class of forms of amaurosis, viz., that characterized not only by subjective, but also by ob- jective symptoms, mentions having met with it most frequently in old persons inclined to marasmus, but sometimes in young persons, especially cachectic adults and atrophic children ; he had also seen it after injuries of the eye. 1900. The reflection from the bottom of the eye, occurring after injuries, has been above explained, (s. 1160 et seq.), and appears to be quite different from the condition, whatever it may be, which gives rise to the appearance in old persons. CHAPTER VI. Section I.—LOSS OF CORRESPONDENCE OF THE SENSATIONS AND MOVEMENTS OF THE TWO EYES. 1901. As an introduction to the present subject, the corre- spondence which naturally exists between the sensations and movements of the two eyes, requires first to be taken into con- sideration. Correspondence between the sensations of the two eyes.* 1902. It has been above shown (s. 1743, et seq.) that the different parts of the same retina exert an influence on each other's sensations. The two retinae, it is here to be shown, likeAvise exert an influence on each other's sensations, but to a much greater and more striking degree. 1903. When the two retinae are impressed in a similar man- ner at the same time, the resultant sensation is much stronger than when one eye only is employed. If the impression on one retina be indistinct, whether from suffusion of the trans- parent media of the eye or from impaired sensibility of the SENSATIONS OF THE TWO EYES. 353 retina, the indistinctness of vision which results, is not so evi- dent when the other eye is used at the same time, as when the affected eye alone is used. 1904. When the two retinae are affected in a dissimilar man- ner at the same time, the mind does not perceive an admixture of the two sensations, but perceives the sensation of one of the retinae only at the same instant of time. Sometimes the one, sometimes the other. Thus, if one eye be closed, and the other be directed staringly towards the window, for example, by and by it will be found that darkness will now and then momentarily overspread the open eye. 1905. But the phenomenon is observed in a much more marked manner, when a different colour is presented to each eye ;* blue to the one, yellow to the other, for example. In this case, an admixture of the two colours, viz., green, is not seen, but either the blue alone or the yelloAv alone; sometimes the one, sometimes the other, or the blue in part and the yel- low in part. 1906. If the dissimilar impressions, it is to be observed, affect parts only of the two retinae, they are perceived sepa- rately, unless the parts of the two retinae which are simulta- neously affected, be their vertices or the various parts equally situated in relation to them on the temporal side of the one retina and on the nasal side of the other, or on the upper parts or the lower parts of the two retinae. These parts are there- fore called corresponding or identical parts. 1907. This may be illustrated by viewing two different coloured wafers, thus:—Place the wafers one on the right hand, the other on the left, at such a distance from each other, that their centres may be about one inch and three-quarters from each other. Hold a board (the board of an octavo book for instance) between the eyes in front of the nose, and look at the wafers in such a way, that the right hand one is seen by the right eye only, and the left hand one by the left eye only. The two wafers are soon seen as if to approximate, and then to run into one or to cover the one the other. This is OAving to the eyes so moving that the images of the two wafers come to be projected on corresponding or identical parts of the two l*PtlT_ HP 1908. It thus appears that dissimilar impressions on corre- sponding parts of the two retinae cannot be perceived by the * A different colour may be presented to each eye by looking through glasses of a different colour at a white object. 23 354 SINGLE VISION WITH TWO EYES. mind at the same instant of time, but only the one sometimes, the other sometimes; though, if the impression on the one retina be much the stronger, it decidedly predominates over, or excludes that on the other. Single vision with two eyes. 1909. An object viewed with both eyes is seen single only AA'hen the optic axes intersect at some point of the object, when the centres of revolution of the two eyes coincide, and when their horizontal and vertical diameters are respectively parallel. Besides the object at Avhich the optic axes meet, other objects to the side of it appear single, provided they are situated in, or Avithin certain limits only, out of an imaginary circular line, or rather spherical surface, called the horoptor, which runs from the point of intersection of the optic axes through the points of intersection of the lines of visual direction in the two eyes. 1910. The correspondence in the direction of the axes, the coincidence of the centres of revolution, and the parallelism of the horizontal and vertical diameters of the two eyes depend on the normal action of the muscles of the eyeballs, which will be considered below. 1911. It is in order that the images of the objects may be simultaneously projected on identical or corresponding parts of the two retinae, that the correspondence in the direction, &c, of the two eyes is necessary; for a single visual perception from a simultaneous impression on each retina results only when that impression affects corresponding or identical parts of the two membranes, (s. 1906.) If other parts of the two retinae than these be simultaneously impressed, the object is seen double. 1912. Whether the faculty by which a single visual percep- tion results from the simultaneous affection of certain parts of the two retinae be connate and dependent on the organization of the optic nervous apparatus, or whether it be a mere matter of experience or association, is a question. 1913. The former vieAV is that which appears best grounded, but the organic condition on which the faculty depends, has not been exactly determined. In a general Avay, however, it may, as above observed, (s. 1766,) be said to consist in the semi- decussation of the optic nerves and some continuity between the fibres of the corresponding sides of the two retinae. 1914. The corresponding parts of the two retinae have been commonly considered to be, or, at least, have been called points. SINGLE VISION WITH TWO EYES. 355 As thus understood or expressed, however, the doctrine is not quite correct; for it has been shown by Mr. Wheatstone, 1st, That images, differing in magnitude Avithin certain limits, but in other respects similar, if projected on parts of the two retinae, as nearly correspondent as may be, coalesce and occasion a single perception. 2d, That in viewing an object of three dimensions, while the optic axes converge, obviously dissimilar pictures are necessarily projected on the two retinae, and yet the mind perceives but a single object, though not exactly like either of the pictures on the retinae. This fact is beautifully illus- trated by Mr. Wheatstone's experiment of simultaneously presenting to each eye, instead of the object itself, its pro- jection on a plane surface as it appears to that eye. 1915. For this experiment Mr. Wheatstone invented an in- strument Avhich he calls a stereoscope. It consists of two plane mirrors, with their backs inclined to each other at an angle of ninety degrees, near the faces of which the two monocular pictures are so disposed, that their reflected images are seen by the two eyes, each looking into one of the mirrors, in the same place. 1916. The experiment may be sufficiently well made by viewing the subjoined figures,—the dissimilar perspectives of a truncated four-sided pyramid, in the same manner as the expe- riment with the wafers above described; viz.:— Fig. 66. Fixing the right eye on the right-hand figure, and the left eye on the left-hand figure, hold between the eyes in front of the nose the board of an octavo book. The two figures will be seen to approximate, and then run into one, representing the skeleton of a truncated four-sided pyramid in bold relief. 1917. From this experiment, Mr. Wheatstone has inferred too much, Avhen he thinks that it overturns the doctrine of 356 SINGLE VISION AVITH TWO EYES. corresponding parts of the two retinae—a doctrine which was held by NeAvton, Reid, Wollaston, and Avhich is held by the best physiologists of the present day. Still it is, as above stated, not exactly in accordance with the doctrine as com- monly expressed. The following observations, however, I believe, will be found to reconcile Mr. Wheatstone's experi- ment with the doctrine of corresponding points. 1918. It has been above shown (s. 1757, et seq.), that the degree of sensibility of the vertex or middle part of the retina is greater than that of the circumferential part; and in illustra- tion of this, reference Avas made to the difference in the degree of sensibility of different parts of the skin as demonstrated by the circumstance whether the mind distinguishes two impres- sions made on the skin close to each other, as two or as one only. 1919. In consequence of the correspondence and sympathy of the two retinae with each other, above shown, it would be a sufficient condition for the perception of an object, if one part only—a half, for example, of its image were projected on the temporal side of one retina, the other half on the nasal side of the other retina. This shows that the two retinae may be in a manner viewed as constituting one sensitive surface. 1920. Hence, as in one and the same retina two impressions, affecting the vertex or middle part, are still perceived by the mind to be two, though very minute and close to each other, so, unless impressions on the middle parts of the two retinae be on corresponding points, they are perceived by the mind as two. But as in one and the same retina two impressions affecting the circumferential part may not be perceived except as one only, even though not very close to each other, so impressions on the circumferential parts of the two retinae, though not on exactly corresponding points, are perceived by the mind as one only ; and that much more readily than in the case of two impressions on the circumferential part of one and the same retina. It is to be observed, that it is not exactly either the one or the other impression which is perceived by the mind exclusively, but is in some measure a mean of the two. 1921. Thus, though the mind perceives separately affections of neighbouring non-corresponding points of the two retinae situated in or near their vertex at the same instant of time, it does not perceive separately affections of the circumferential parts of the two retinae, resulting from impressions on neigh- bouring non-corresponding points. The distance betAveen the SINGLE VISION AVITH TAVO EYES. 357 neighbouring non-corresponding points which are impressed, it is to be observed, being Avith certain limits. 1922. In Mr. Wheatstone's experiment, it is that part of the object at which the optic axes intersect, the image of which is projected on the middle parts of the two retinae. Now, of the per- spectives of the objects which are projected on the two retinae, this is the only part which is similar for the two eyes. It, therefore, falls on corresponding points, the condition necessary for a single visual perception, from an affection of the middle parts of the two retinae. 1923. It is, on the contrary, those parts of the object out of the horoptor, the image of which, necessarily dissimilar for the two eyes, is projected on the circumferential parts of the retinae —the very parts, affections of accurately corresponding points of Avhich is not, as above seen, a necessary condition for a sin- gle visual perception. 1924. According to this, if, when reference is made to the correspondence of the circumferential parts of the two retinae, the expression corresponding or identical compartments be substituted for corresponding or identical points, and if the lat- ter expression be employed only Avhen reference is made to the correspondence of the middle parts of the two retinae, then the doctrine of corresponding parts of the two retinae, so far from being overturned, is confirmed and illustrated by Mr. Wheat- stone's experiments, as I shoAved several years ago,* and as has also been shown in Germany by Bruecket and Tourtual.J 1925. Visual perception of the three dimensions of space. —All that can be perceived of an object of three dimensions by means of one eye may be represented on a plane surface, but it is not so in regard to Avhat can be seen of it by means of the two eyes with their axes in a state of convergence. In the former case, a semblance of solidity or depth is seen, and this is all that a picture can represent; in the latter case, solidity or depth is perceived as actually as it may be by the touch of two fingers, and this is what a picture cannot represent. This is OAving to the position of the two eyes, by which each is fitted to receive on its retina a different perspective of the object. 1926. The mode in which this is effected by the two eyes is essentially analogous to the mode in which the third dimension * Proceedings of the Royal Society for 1839-40, and article Diplopia, Cy- clopaedia of Practical Surgery. t Muller's Archiv. for 1841. X Die Dimensionen der Tiefe im freien Sehen und im stereoscopischen Bilde. Munster, 1842. 358 CORRESPONDENCE IN MOVEMENTS OF THE EYEBALLS. is perceived by the touch. With the mere surface of the point of one finger Ave can take cognizance of length and breadth only, but with two fingers we can perceive thickness also. The two fingers admitting of being applied to different parts of the object, receive impressions of different perspectives, as it were, of it. Natural double vision with two eyes. 1927. It is to be remarked, that we do not see with the two eyes every object single; and the reason is, that the more pro- jecting, for example, an object is, the more is some part of it out of the horopter, and therefore the more dissimilar are its perspectives to the two eyes. Now, when the pictures on the two retinae are very dissimilar, the parts which ought to coalesce occupy places far beyond the limits at which points of the two retinae are influenced by each other; and therefore an object such as a needle, for instance, looked at with one end directly towards us, is seen bifurcated or double. Correspondence in the movements of the two eyeballs.* 1928. A correspondence in the direction of the optic axes, coincidence of the centres of revolution, and parallelism of the vertical and horizontal diameters of the two eyes, it has been above shown, are necessary conditions, in order that the images of objects may be simultaneously projected on corresponding points and parts of the two retinae; that they are therefore the remote conditions on which single vision with the two eyes de- pends. In the course of the movements of the eyeballs, these conditions must therefore be preserved. 1929. The eyeball lies balanced, as it were, in the orbital capsule, and the movements Avhich it is made to execute by the action of its muscles are revolutions merely around a certain point in its interior, the situation of which in the orbit always remains the same when the movements of the eyeballs are natural. 1930. As the eyeball revolves in all directions, it has three axes, on which it is made to revolve by its six muscles, in as many different primary directions. 1931. Suppose the six muscles of the eyeball in a state of equilibrium by Avhich the pupil is directed exactly forwards, and the optic axis is horizontal; then:— 1st. The axis of revolution for the rectus externus and * Ruete, Lehrb ch der Ophthalmologic fiir Aerzte und Studirnede, Braunschweig, 1845. CORRESPONDENCE IN MOVEMENTS OF THE EYEBALLS. 359 internus is vertical, artd coincides with the vertical axis of the eye. These muscles turn the pupil outwards or inwards. 2d. The axis of revolution for the rectus superior and in- ferior, inasmuch as these muscles proceed to the globe in the direction of the optic nerve, Avhich intersects the optic axis at an angle of about twenty degrees, extends obliquely from before and inwards, somewhat backwards and outwards, and intersects the optic axis at an angle of about seventy degrees. The pupil is thus turned by the rectus superior upwards and somewhat inwards, by the rectus inferior downwards and somewhat inwards. 3d. The axis of revolution of the obliqui likewise extends horizontally through the eyeball, but nearly from the outer margin of the cornea backwards and inwards, and intersects the axis for the superior and inferior recti at an angle of about seventy-five degrees. Around this axis, when the optic axis is horizontal and directed forwards, the superior oblique turns the eyeball in such a Avay that the pupil is directed down- wards and outwards, and the inferior oblique turns it in such a way that the pupil is directed upwards and outwards. The annexed figure (67) represents these circumstances. The oblique muscles turn the eyeball in the direction above indicated, only when the pupil is previously directed straight forwards and all the muscles are in a state of equilibrium. But if, for example, the internal and inferior recti have pre- viously directed the pupil downwards and inwards, then the superior oblique turns it still more inwards. 1932. The four recti are antagonists of the two obliqui; the recti muscles pull the eyeball back, the obliqui forwards. The eyeball is in the sound state thus balanced. 1933. If one of the four recti muscles be cut, the eyeball protrudes somewhat. When one of the oblique is cut, the eyeball sinks deeper in the orbit. 1934. The two obliqui, with the external rectus, are antago- nists of the superior, inferior, and internal recti. 1935. By the mechanism just mentioned, assisted by the orbital capsule, the eyeball is balanced in such a way that when all the muscles are in equilibrium the optic axis is directed ho- rizontally forwards., 1936. The four recti rotate the eyeball in the vertical and horizontal directions. The obliqui keep the vertical diameter of the two eyes always parallel though not vertical—a condition necessary for single vision. 1937. The internal rectus muscle of one eye, and the exter- 360 CORRESPONDENCE IN MOVEMENTS OF THE EYEBALLS. nal rectus of the other, usually act together, so also do the superior recti of the two eyes and the inferior recti. 1938. But when required for the purposes of vision the two internal recti act together, and so also may the two external A Si. es •- __! _• .„ s o 3 __; ■_; B » 4) g . _ > fin o-w_s g_, » u hS_ a a o m •_; ■«' DOUBLE VISION WITH TWO EYES. 361 recti in bringing the eyes from a state of strong convergence to a state of parallelism, but not of divergence. 1939. In short, the different muscles of the two eyeballs act in various combinations, sometimes as fellows, sometimes as antagonists, according to the manner in which the eyes require to be directed to receive the images of the object looked at, on corresponding parts of the two retinae. LOSS OF CORRESPONDENCE IN THE SENSATIONS OF THE TWO EYES. Diplopy or double vision with two eyes. 1940. The conditions on which single vision, as well as natural double vision with the two eyes depends, having been premised, we are prepared to enter upon the study of morbid double vision with two eyes. 1941. In limine,it maybe observed, that double vision Avith two eyes is altogether different in its nature from the double or manifold vision with a single eye above considered, the lat- ter being owing to irregular refraction. A case of double vision with two eyes is at once distinguished by closing one eye, when objects will be seen single. 1942. Where, from any cause, there is a loss of the natural correspondence of the optic axes, the coincidence of the centres of revolution, and the parallelism of the vertical and horizontal diameters of the two eyes, the parts of the two retinae on which images of the same object are simultaneously projected, are not corresponding parts ; therefore, in accordance with what has been above said, the sensations arising from the two im- pressions are separately perceived by the mind, and the conse- quence is double vision. 1943. Double vision with two eyes is thus in itself not a disease, but the natural result of derangement of those conditions on which single vision depends. The proximate cause of the derangement alluded to is, most frequently, paralysis of some one or more of the muscles of the eyeball; but it may be some morbid production in the orbit, or the like, displacing the eye- ball. 1944. The two images in diplopy are often distinguished into true and false, or real and imaginary; but such a distinction is improper, as the image perceived by the displaced eye al- though it may be less distinct, is not more false or imaginary than the other, both being equally the result of sensation pro- duced by the impression of rays of light on the retinae. 1945. That one of the two images is more distinct than the 362 DOUBLE VISION WITH TWO EYES. other, is OAving to the circumstance, that in one eye the impression is made on the central part of the retina, which is more sensible than any other; while in the opposite eye, the impression falls on a part of the retina which, according to the degree of deviation of the eye from its right direction, is more or less distant from the centre. The adjustment of that eye, moreover, which receives the impression on the centre of its retina, corresponds with the distance of the object looked at. The other eye, not being so adjusted, its image besides being indistinct, is surrounded by an iridescent halo (s. 1688, 2d.) 1946. The relative position of the two images depends upon the direction and degree of the deviation of the eyes. As sometimes the deviation of the axes or centres and diameters of the eyes exists only Avhen the person looks in particular direc- tions and at certain distances, so does the double vision in such cases take place only when the patient looks in those directions, and at those distances; thus, if the abductor muscle of the right eye be palsied, the patient sees single on looking to the left, but double on looking to the right. [Where the deviation is in the horizontal axis of the eyes, a horizontal line appears double, whilst a vertical line is seen single; on the contrary when the deviation is in the vertical axis, a vertical line appears double, whilst a horizontal one is seen single. Sometimes the double lines are parallel, at others divergent. If the head be held erect and the line be moved, horizontally or vertically as the case may be, the double images will be found to approach or recede accordingly as the line approaches or recedes from a certain point, and in some cases at one point the two images unite—double vision ceasing. Examples of all these conditions of vision have come under our observation.] 1947. When double vision is owing to deviation of the optic axes, the misdirection of the two eyes may exist in various degrees, from an evident squint to a scarcely perceptible cast. 1948. When, on the contrary, double vision is owing to deviation of the vertical and horizontal diameters of the two eyeballs from parallelism, in consequence of abnormal action of the oblique muscles, there is no deviation of the optic axes, and, consequently, no squint or cast. 1949. The double vision from deviation of the optic axes is less perceived by the patient Avhen this is great than when it is slighter, because in the latter case, the two retinal sensations are about equal in force, in consequence of the images of the STRABISMUS. 363 object being projected on parts of the tAvo retinae not differing much in sensibility. 1950. As in double vision from deviation of the vertical and horizontal diameters of the two eyes, the images of the object are equally projected on the central parts of the two retinae, so the two retinal sensations do not differ in force; hence the two sensations contend, as it were, to attract the mind's attention, and the object appears as if oscillating Avith velocity before the eyes, the consequence of which is great confusion of per- ception when the tAvo eyes are open, and sometimes vertigo. As the person in this state can exercise vision only when he closes one eye, the affection has been named Monoblepsis. 1951. When the non-correspondence of the two eyes is very slight, the two images seem partially to overlap each other. This appearance not being recognized as a phenomenon of double vision, is sometimes described under the name of Meta- morphopsy. 1952. The irregular or impeded action of the muscles of the eyeball, giving rise to diplopy, may be OAving to an affection of the muscles themselves or of their nerves, or it may be owing to disease or injury of the brain, or to drunkenness, or fear, or to derangement of the primae viae, &c. But this is not the place to discuss those various primary affections on Avhich the derangement of the action of the muscles of the eyeballs depends. It is enough here to explain the nature of diplopy with two eyes, in order that, as a symptom in any particular disease, it may be appreciated at its due value. LOSS OF CORRESPONDENCE IN THE DIRECTION AND MOVEMENTS OF THE TAVO EYES. Strabismus, or squinting, and luscitas, or immovable distor- tion of the eyeballs. 1953. Strabismus and luscitas are equally characterized by loss of the natural correspondence of the optic axes; but in the former, this is owing to want of harmony in the movements of the eyes, not to loss of motive poAver, for the squinting eye be- comes straight and capable of being directed to any object when the other eye is closed; whilst in the latter, it is owing to one eye being fixed more or less immovably in one direction, in consequence either of paralysis of the muscle moving the eye- ball in the opposite direction, or of organic contraction and ad- 364 STRABISMUS CONVERGENS. hesion of the muscle, &c, of the side to which the eyeball is turned. 1954. The following are the principal forms of strabismus:— 1. Strabismus convergens; 2, strabismus diver gens; 3, strabismus sursumvergens; 4, strabismus deorsumvergens. 1955. Of these different forms, by far the most frequent is strabismus convergens. 1956. Strabismus diver gens, though rare, is next in frequen- 1957. Strabismus sursumvergens and strabismus deorsum- vergens are very rare. J 958. It is to be remarked that the affected eye is not always turned exactly inwards, outwards, upwards, or downwards, but may be inclined in the intermediate directions; sometimes in a state betwixt strabismus sursumvergens and strabismus conver- gens, and sometimes betwixt strabismus sursumvergens and strabismus divergens. Strabismus convergens. 1959. Objective characters.—In convergent strabismus, the pupil of one eye is habitually more or less turned towards the nasal canthus, whilst the other eye looks straight forward and is capable of being directed to the various objects on which the person fixes his regard. It is only when the habitually well- directed eye is closed, that the inverted eye becomes straight and falls under the command of the patient to be turned in any direction; but as soon as the former eye is again opened, the person loses all command over the other, and it falls back into its original state of inversion. 1960. When the habitually well-directed eye is covered it squints, while the previously squinting eye becomes properly directed. 1961. The strabismus which passes to the previously well- directed eye when this is covered, is called alternating strabis- mus convergens, the appellation of double strabismus conver- gens being confined to cases in which both eyes are habitually more or less turned in at the same time; one cornea perhaps being more than half hid in the inner canthus, while the other has a slight inclination inwards. 1962. In some cases of alternating strabismus, the patient has the power, immediately and voluntarily, to direct either eye properly; but while this is done, the other falls into the state of inversion. 1963. In other cases the habitually squinting eye becomes STRABISMUS CONVERGENS. 365 straight, and the opposite eye squints without the will of the patient; and Avhile both eyes are open, there is power to direct properly one eye only. 1964. Alternating is much more frequent than double con- vergent strabismus. In regard to the relative frequency with which the right or the left eye is turned in, it appears that the left eye is rather more prone to be so than the right. 1965. Subjective symptoms.—The vision of an eye affected with convergent strabismus is usually imperfect. An early symptom is double vision, though of this the patient does not continue long sensible. It is, however, always found, that if the vision of both eyes is tolerably good, and the attention is fairly fixed on their sensations, single objects held directly be- fore the face are seen double. 1966. The double vision usually attending strabismus is OAving to the circumstance that non-corresponding parts of the two retinae are impressed by the rays of light proceeding from the same object (s. 1942). 1967. The image seen by the properly directed eye appears clearer than the other; which is OAving not only to that eye being the stronger, but especially to the circumstance that in it the impression is made on the central part of the retina, which is more sensible than any other; besides, that the adjustment of the properly-directed eye corresponds with the distance of the object looked at (s. 1945). 1968. The image of the affected eye is clearer, and, in con- sequence, the diplopy more striking, the less the cast of the eye; hence the double vision will be noticed by the patient before the misdirection of the eye attracts the attention of those about him. Double vision ceases in many cases, because the impression on the sound eye is much more vivid than that on the distorted one; and we know by experiment, that of impres- sions dissimilar in force on the two eyes, the mind perceives the stronger, to the exclusion of the weaker. 1969. Causes.—The remote causes to which' strabismus is in different cases attributed, or attributable, are very various. They are such as the following:—Convulsions during infancy, difficult dentition, hooping-cough, measles, small-pox, worms, injuries and diseases of the head, fright, anger, injuries, inflam- mation, and other diseases of the eyes, such as opacities of the cornea, imitation, and a habit of misdirecting the eyes. 1970. Most commonly, strabismus has its origin in early life; indeed, many of the diseases just enumerated as remote causes of the affection, are diseases of early life. 366 STRABISMUS CONVERGENS. 1971. In many cases no cause at all can be assigned. 1972. Is defective vision of one eye a cause of strabismus ? —In most cases the vision of the squinting eye is imperfect; but, it may be asked, is this cause or effect, or are not the de- fective vision and strabismus both effects of one and the same cause? 1973. As both eyes have a tendency, the one to turn in, while the other remains straight, imperfect vision of one eye will operate as a cause of rendering the squint habitual in that eye, for the reason that, as one eye only can be directed straight at one time, it is naturally the stronger eye which is so. In this case it is to be remarked, however, that the imperfect vision is not the cause of the squint itself; it is merely the cause of determining it to one eye rather than to the other. The just- ness of this view is illustrated by the fact, that by binding up the stronger eye, and strengthening the weaker by exercise, the strabismus will shift from the latter to the former. 1974. Supposing defective vision of one eye to have some causal connection with the origin of strabismus itself, it can scarcely ever be the efficient cause, as much more frequently all degrees of defective vision of one eye exist without the occurrence of strabismus; and blind eyes are not more prone to squint than sound ones. 1975. Proximate cause.—Whatever be the remote cause of strabismus, there can be no doubt that its proximate cause con- sists in some affection of the muscles of the eyeball. The question which this conclusion naturally suggests is, what is the nature of the affection of the muscles of the eyeball? 1976. The various remote causes of strabismus which have been remarked, such as imitation, affections of the mind— anger, fear, &c,—disease of the brain, intestinal canal, and other parts, together with the circumstance, that it may occur occa- sionally only, and the phenomena of strabismus in general, all point to the muscular affection being owing to perverted ner- vous action. 1977. In strabismus convergens, is it the action of the ad- ductor or abductor which is at fault? If the adductor, it must be in a state of tonic spasmodic contraction, Avith this pecu- liarity, that the spasm goes off when the other eye is closed, and immediately returns when it is again opened; and with this further peculiarity, that on closing the previously well-directed eye, the spasm comes on in it at the same time that it goes off in the habitually squinting one. 1978. Is it the abductor which is at fault? The abductor is STRABISMUS CONVERGENS. 367 certainly not paralyzed, for on closing the habitually straight eye, it evidently exerts its proper function; but, as soon as the latter is again opened, the abductor is no longer able to support the eye in its natural direction, so that the distortion imme- diately returns. If the abductor be in fault it is obvious that the fault, whatever it is, is transferable from the muscle of the one eye to that of the other. 1979. It has been inferred from the eye not always turning out to the external canthus, on the section of the internal rectus muscle, that the external rectus was paralyzed, but it appears that the action of the inner fibres of the upper and lower recti, which are advantageously inserted for the purpose, are in general sufficient to restrain the everting action of the external rectus (s, 1931, 2d). 1980. Organic change of the affected muscle, or contraction of surrounding parts, may, hoAvever, supervene; such as con- traction and thickening of the conjunctiva on the side towards which the eyeball is turned, and an hypertrophied state of the muscle, as appears from post-mortem examination, but especially from observations made during the operation of dividing the muscle at fault. The strabismus thus merges into luscitas. 1981. It is thus seen that there are two distinct sets of cases of convergent misdirection of the eyes, viz., strabismus and luscitas, and that in the former there is in general nothing ab- normal perceptible about the organic constitution of the muscles at fault, whilst in the latter there is somewhere organic con- traction. But, between cases which may be called pure con- vergent strabismus and cases of luscitas, there are gradations in Avhich the patient still has more or less power to turn the eye out. 1982. Treatment.—When convergent strabismus is of recent origin, is still purely dynamic, and if its exciting cause can be discovered, and is still in operation, this ought to be the first object of treatment. 1983. In every recent case of strabismus in a young person, where the exciting cause is not evident, it is advisable to pre- scribe a calomel purge or two, and then an alterative course of mercurial chalk, with an occasional laxative, followed up by tonics. 1984. It is scarcely necessary to say, that whatever prompts to a habit of misdirecting the eyes, whether imitation, trying to look at objects too near the eyes, or otherwise disadvantageously placed, careless employment of the eyes, and the like, must be carefully guarded against. 368 STRABISMUS CONVERGENS. 1985. Exercise of the habitually misdirected eye during two or three hours daily, by covering the other eye, has often been found successful in curing squint. But it is apt to happen that whilst the habitually misdirected eye becomes straight, the pre- viously well-directed one turns in. 1986. When strabismus convergens has become fully estab- lished, it resists, as is well known, all treatment such as that above indicated. 1987. Section of the internal rectus as a means of cure.— Ocular myotomy appears to have been practised by the celebra- ted itinerant oculist the Chevalier Taylor, as a means of curing strabismus, about a hundred years ago; but it never came into use as a regular surgical operation, and so was forgotten. 1988. Of late years, however, it has been revived. Sugges- ted by several different persons independently, and tried on> the dead body by Stromeyer especially, the operation on the living body was first introduced into actual practice by Dieffenbach. 1989. It has been seen that in pure strabismus, there is in general nothing abnormal perceptible about the organic constitu- tion of the muscle at fault, whilst in luscitas there is either par- alysis or organic contraction. Such being the case, the attempt to remedy organic luscitas by operation, every one must admit, was justified by analogy with clubfoot; but certainly the same cannot be said for the operation in pure strabismus. It must be confessed, however, that the operation in cases of pure stra- bismus has proved more successful than could a priori have been expected. 1990. Section of the internal rectus of the habitually misdi- rected eye alone may be sufficient, but section of the internal rectus of both eyes is generally necessary, as it is found that, if one eye only is operated on, it either still remains inverted, or, if it is rendered straight, the previously well-directed eye is apt to turn in. 1991. The latter circumstance is analogous to that above pointed out, viz., that Avhen the previously well-directed eye is covered, and the habitually inverted one, by being thus called into exercise, becomes straight, the former turns in. 1992. In double convergent strabismus both internal recti should in like manner be divided at the same time. 1993. Position of the patient, assistants, and operator.-— This is to be arranged as above indicated for cataract (s. 1298, et seq.) 1994. Securing of the eyelids.—For securing the eyelids specula have been much employed, but they may be dispensed STRABISMUS CONVERGENS. 369 with, and the eyelids secured as above recommended for cata- ract, (s. 1303,) only that this must be done wholly by the as- sistants, as both hands of the operator are necessarily engaged. One assistant may take charge of both eyelids if there is not a second at hand. There should, however, be an assistant ready with small pieces of sponge, to sponge away the blood, which sometimes flows after the division of the conjunctiva, and collects in the wound. 1995. Section of the internal rectus.—The opposite eye being covered, the patient is to be directed to turn the eye to be operated on as much outwards as he can. Whilst he does this, the surgeon, with a toothed forceps held in his left hand, seizes the conjunctiva at about a quarter of an inch from the margin of the cornea on the nasal side, and raises it up in a large transverse fold, which he immediately divides with a pair of straight blunt-pointed scissors, so as to make a free vertical incision through the conjunctiva. This incision may be en- larged with the scissors upwards and downwards, if not at once long enough; but the whole length ought not to exceed one- fourth or one-third of an inch. By this division of the conjunc- tiva, the tendon of the internal rectus, which is inserted into the sclerotica at about one-sixth of an inch from the margin of the cornea, is exposed. 1996. The next step is to pass a bent probe or blunt hook behind the tendon, between it and the sclerotica, from above downwards; bringing its point, when fairly passed behind the tendon, out through the lower end of the incision of the con- junctiva, by raising its handle. 1997. The tendon of the muscle being thus raised on the hook, the next step is its section, which is effected with the scissors, from below upwards, near its insertion. 1998. If, after this is done, the eye does not admit of being freely everted, an exploration of the bottom of the wound is to be made with the hook, in order that if this be owing to any bands of cellular tissue remaining uncut, they may be raised and divided. 1999. The immediate effect of division of the internal rectus of one eye in convergent strabismus, may be, that the axis of the eye becomes directed straight forward, and can be preserved so though the other eye is kept open. If, however, this should not be the case, but the eye still remained inverted, division of the internal rectus of the opposite eye should be forthwith performed 2000. That the axes of the tAvo eyes, though they may ap- pear to do so, do not correspond immediately after the operation, 24 370 STRABISMUS CONVERGENS. is shoAvn by the circumstance that double vision has been in most instances an immediate result of the operation, but it has usually gone off sooner or later. 2001. The reason of double vision occurring after, when per- haps it did not exist before, the operation, when the axes of the eyes deviated so much more, appears to be this:—the rays of light from the object regarded by the sound eye, were either not at all received on the retina of the squinting eye, or if so, received in a place considerably removed from the most sensible part, and the impression on which, therefore, was too Aveak to fix the attention ; whereas, after the operation, the rays striking, in the eye operated on, a part of the retina nearer the centre, the sensation is strong enough to attract notice, but, the axes of the two eyes not yet quite corresponding, there is double vision. 2002. It has sometimes been remarked that the vision of the eye became Aveaker after the operation, but soon improved again. More frequently, considerable improvement in the vision of the eye operated on has been, or has been fancied by the patient to have been, a result of the operation. Generally, however, there is no actual change in the retinal power, and rectification of the squint is all that is gained from the operation. [This does not entirely accord with our observations. In nearly all the cases of single strabismus which have fallen under our observation, there was a weakness in the retinal power of the affected eye, and in all such upon which we have operated the vision has improved after the division of the muscle. These facts we have determined by careful experiments, so that we could not be misled by the fancy of the patient.] 2003. Unnatural prominence of the eyeball amounting sometimes to semi-dislocation, has been a common result of the division of the internal rectus. This is owing in some degree to the unrestrained action of the oblique muscles, and cannot be altogether avoided, but there is no doubt that it is in a greater measure owing to too free division of the conjunctiva, division of the muscle too far back, and too great detachment of its cellular connections with the eyeball. 2004. Eversion of the eye after section of the internal rectus by the action of the external rectus has much less frequently happened than might have been anticipated. This is owing in a great measure, as above said (s. 1979), to the inverting action of the inner fibres of the superior and inferior recti. 2005. In cases of eversion the eye may eventually turn right. If it does not, division of the external rectus must be had re- course to. STRABISMUS SURSUMVERGENS, ETC. 371 Strabismus divergens. 2006. Strabismus in all respects analogous to convergent strabismus, except that the misdirection of the eye is outwards, is rare. 2007. Divergent luscitas from paralysis of the muscles sup- plied by the third pair, must not be confounded with divergent strabismus. 2008. The eversion which sometimes occurs after section of the internal rectus for convergent strabismus, inasmuch as the eye can still be moved somewhat from the external angle when the other eye is closed, partakes partly of the characters of stra- bismus and partly of those of luscitas. 2009. Treatment.—The same general treatment and exercise of the eye, above recommended for convergent strabismus, may be tried in recent cases. 2010. Myotomy has not been so successful in divergent as in convergent strabismus. The return of the eye from its state of eversion to a straight direction after section of the external rectus is but very gradual. 2011. Division of the corresponding recti of both eyes at the same time is equally applicable to divergent as to convergent strabismus. 2012. Section of the external rectus.—This is performed in essentially the same manner as that of the internal rectus, it being remembered that the insertion of the tendon of the exter- nal rectus is as much as a quarter of an inch from the margin of the cornea, and is thinner and more spread out than that of the internal. Strabismus sursumvergens and strabismus deorsumvergens. 2013. The turning up and turning down of the eyes, com- prehended under these names, appear to be rather examples of luscitas, than pure strabismus. 2014. Cases have been met with, in which the eye having been previously directed inwards and upwards, turned right upwards, after the section of the internal rectus, and was brought back to a natural position only by section of the superior rectus. 2015. In reference to section of the superior rectus, it is to be remembered that the insertion of its inner fibres is nearer the margin of the cornea, but that the average distance of the inser- tion from the margin of the cornea is about a quarter of an inch. 2016. The insertion of the inferior rectus is similar to that of the superior, but not quite so far from the margin of the cor- 372 PARALYSIS OF THE NERVE OF THE THIRD PAIR. nea, being only about one-fifth of an inch. Section of the in- ferior rectus does not seem ever to be required. 2017. Treatment and accidents after the operation of ocular myotomy.—In general, little treatment is required. It is always advisable that the patient-should be kept at rest for a day or two after the operation. A cold lotion may be applied to the eye (s. 110), but if pain come on, warm fomentations will be better. 2018. The accidents which have occurred during and after the operation, are:—The eyeball cut into and the vitreous hu- mor evacuated- Hemorrhage to a dangerous extent. Inflam- mation of the conjunctiva with chemosis. Inflammation in the orbit, ending in abscess. Panophthalmitis ending in total de- struction of the eye. Convulsive movements of the eyeball. Many of these accidents, however, there can be no doubt, have been owing to a rude performance of the operation. 2019. When a return of the strabismus takes place, the ope- ration may be repeated. Sometimes success has been obtained only after a second or third repetition. Paralysis of the muscles supplied by the nerve of the third pair. 2020, The muscles supplied by the nerve of- the third pair, being the levator palpebrae, the internal, superior, and inferior recti, the inferior oblique and the sphincter fibres of the iris, the result of their paralysis is: 1st. Paralytic ptosis. 2d. Paralytic divergent luscitas, with paralytic ophthalmo- p-osis. 3d. Paralytic mydriasis. 2021. Paralytic ptosis.—This is a hanging down of the upper eyelid over the eye, in consequence of paralysis of its levator muscle permitting of the unrestrained action of the or- bicularis palpebrarum. The patient can thus open his eye only by raising the eyelid with his finger. 2022. Paralytic divergent luscitas.—When the upper eyelid is raised with the finger, the eye is seen to be everted in con- sequence of the paralysis of the internal superior and inferior recti permitting of the unrestrained action of the external rectus. The patient is at the same time unable to move the eye upwards or downwards. From the non-correspondences of the two eyes occasioned by the eversion, the patient sees double, and is apt to become giddy if he attempts to walk while he holds the eye open. 2023. Paralytic ophthalmoptosis is unnatural prominence of the eyeball in consequence of the paralysis of the internal, PARALYSIS OF THE NERVE OF THE THIRD PAIR. 373 superior and inferior recti allowing of the unrestrained action of the superior oblique. 2024. Paralytic mydriasis.—As above explained, this is persistent dilatation of the pupil, notwithstanding exposure to light, owing to the paralysis of the circular fibres of the iris permitting of the unrestrained action of the radiating ones, (s. 1610.) 2025. Paralysis of the nerve of the third pair may be com- plicated Avith paralysis of the nerve of the sixth pair, in Avhich case the external rectus being also paralyzed, the eye is no longer turned towards the temple; or it may attend paralysis of the optic nervous apparatus. In this case the defective vision is to be distinguished from that disturbance of vision which is owing merely to the simple mydriasis in uncomplicated para- lysis of the nerve of the third pair. 2026. Causes.—Paralysis of the parts supplied by the nerve of the third pair sometimes comes on under the same circum- stances as rheumatism, viz., exposure to cold and damp. Such cases are properly viewed as being of a rheumatic character. 2027. The cause of the paralysis, however, is often, conges- tion, extravasation, effusion, a tumour, 86' Fi&* 87, style are well known (fig. 86). It is usu- ally made of lead or silver. One may be easily made for an occasion, by taking a bit of lead wire of the proper length and thick- ness, smoothing its surface, rounding one end and bending the other, thus : (fig. 87.) 2507. A thinner style is to be followed by a succession of thicker ones, until one of a moderate thickness can be borne ; or the duct may be first prepared for the re- ception of a moderately thick style by the previous use of catguts, as above described. 2508. The patient soon learns to manage the metallic style himself—a great advantage, considering the length of time the employment of means for dilating the nasal duct requires to be persisted in. 2509. Whatever be the means employed for dilating the nasal duct—mesh, catgut, or metallic style—the passage is to be cleansed on every reapplication by injections of tepid water. After which some astringent lotion is to be thrown in, or the dilating body may be employed as the vehicle of some medica- ment, in the form of salve, with which, when about to be intro- duced, it is to be smeared. The bichloride of mercury collyrium, and the red precipitate ointment, are perhaps the best applica- tions, in general, that can be made to the diseased mucous membrane of the duct. The nitrate of silver, in the form of -\., the eye), want of power to distinguish colours. Aegilops (_.ryi'x<_4, from «"£, alyh, a goat, _)^f,, fa eye), a name given by the older surgeons to a sinuous ulcer at the inner corner of the eye, from its resemblance to the larmier, or infra-orbital glandular sac of goats and other ruminating animals. Albugo (albus, white), an opacity of the cornea. Amaurosis (_,^*_._f_»o-«f, obscuration, from <_n_.a_g._., to render obscure), im- pairment or loss of \rision from paralysis of the optic nervous apparatus. Amblyopia (a^gx.j, dull, Si-\., the eye), impaired vision from defective sensibility of the retina. Amphiblestboiditis (a^iflx.-"--^"-^., fa retina, from <_f.i0x»i_-rg-., a net, and _7._?, form), retinitis, or inflammation of the retina. Axchilops (ayxl\tu-\., from ayxh near, and S>-\,, the eye), name given by the older surgeons to the abscess at the inner corner of the eye, ending in the sinuous ulcer which they called Aegilops. Awchtloblepharox (dyx.Xo?, crooked, /-Xe_.£--, eyelid), cohesion of the eyelids to each other at their borders. Asthesopt (a, priv., o-.-vof, strength, and <_4, fa eye), weaksightedness. Atresia (a, priv. rireiu, to perforate), closure or imperforation; applied to the pupil, &c. Blepharitis (/-X_*e.., eyelid), inflammation of the eyelids. Blepharoble_.j.orrh__a O-X-tagoy, eyelid, /_x.w«, mucus, '?ku, to flaw), first stage of puro-mucous inflammation of the conjunctiva. Blepharophthalmia (0x_f<_;«, eyelid, 3f___Ap«c, eye), called also Blephar- ophthalmo-blennorrhcea, puro-mucous inflammation of the conjunctiva in its fUlly-formed state. ,•_.__. Blepharoplegia 0_X.t_.f-v, eyelid, n\ny., stroke or blow), paralysis of the e3BLEPHAROPTOsis (0x. from p^aivo, to gape; or xy/xva-tc, from x"/"".) humour, orjluid), elevation of the conjunctiva like a wall round the cornea, from exudation into the subjacent cellular tissue. Choroiditis (choroid, from xpgiov, chorion, one of fa membranes of the fatus, £»_.?, likeness), inflammation of the choroid. Chromatopst, or Chromopst (;^_y*_., colour, etyij, vision), chromatic or coloured vision. Chroopst, or Chrupst (^joa, colour, J^if, vision), chromatic vision. Cilia (celo, to cover or conceal, because they cover and protect the eye, or from cieo, to move), eyelashes. Cirsophthalmia (x«fo".f, varix, oxo?, hook), hook invented for the operation for artificial pupil by separation. Coreplastice (xo{i», pupil, irXaeriKri, the art of making images), operation for artificial pupil in general. Cornea (cornu, horn), the cornea is so called from its horny appearance. Corotomia (x«£», pupil, tIjukw, to cut), operation for artificial pupil by incision. Curette (French for a small spoon), Daviel's spoon, an instrument used to assist the exit of the lens in the operation of extraction. Dacrtoadenitis (&, to weep, xus-tij, sac, ff\cna, mucus, p__>, tojlow), blennorrhoea of the lachrymal sac. Dacryoh_gmorrhysis ($*xf._>, to weep, al'/xa, blood, fete, tojlow), sanguine- ous lachrymation. Dacryolites (.axe._), to weep, x.fl.f, a stone), calculous concretions depo- sited in the lachrymal passages. Dacryoma (,ax{-_), to weep), stillicidium lachrymarum. Diplopy (_twX._c, double, 2>j,, vision), double vision. Distichiasis (_■??, twice, a-Ti^o?, a row), a form of trichiasis in which the mal-directed eyelashes form a second row, distinct from the others. Ectropium ('Ex-rf mov, from ix, out, reevco, to turn), eversion of the eyelids. Excastthis (l», in, xatdo;, fa corner of the eye), enlargement of the lach- rymal caruncle. Entropium (Iv, in, ■.£__•_., to turn), inversion of the eyelids. GLOSSARY. 483 Epicanthus (__-», upon, xavSoc, angle of the eye), a congenital peculiarity of a fold of skin extending over the inner canthus. Epiphora (etti, upon, fi^u, to carry), watery eye from excess of lachrymal secretion. Exophthalmos and Exophthalmia (_£, out, 59_.Xj-t.c, eye), protrusion of the eyeball. Exophthalmos is used when the eyeball is otherwise unin- jured; exophthalmia, when, in addition to the protrusion, there is disorgan- ization of the eyeball. Gerontoxon (yifx_», old, ro'fov, a bow),- arcus senilis. Glaucoma (yXawt.f, sea-green), a greenish opaque appearance behind the pupil. Grando (hailstone), a small tumour of the eyelid. Gutta opaca, name given by the Arabians to cataract, as they supposed it an opaque drop in front of the lens. Gutta serena (drop serene), name given by the Arabians to amaurosis, supposing it to depend on a clear drop fallen from the brain into the eye. H_emophthalmos, H_kmophthalmia (tt.ifA.it, blood, o8aX/_vof, fa eye), san- guineous effusion into the eye. Hemeralopia (nfjis^a, day, S^tc, vision), night-blindness. It has been also employed to mean day-blindness (./_Eja, day, a priv., or aXa.c, blind, .-vj-if, vision). Hemiopy (nf/.urv{, half, o^k, vision), a defective state of vision, in which one half of objects only is seen. Hordeolum (hordeum, barley), stye. Hyaeitis, or Hyaloiditis (SaXoc, glass), inflammation of the hyaloid membrane. Hydrophthalmia, or Hydrophthalmos (viae, water, .$9aXf*.c, fa eye), dropsy of the eye. Hyperkeratosis (vine, above, x£<»_.j, cornea), conical cornea. Hypo_ema (biro, under, a"y.a, blood), blood in the anterior chamber. Hypochyma (.w.^u/u-a, or vnoxytrti;, from biro, under, x-j<_a, effusion), cataract. Hypogala (viro, under, yaXa, milk), effusion of a milky like matter in the anterior chamber. Hypopyon (vwo, under, w.ov, pus), pus in the anterior chamber. Iriankistron ("j.?, iris, ayxie-Tgov, a jish-hook), an instrument invented for performing the operation of artificial pupil by separation. Iridauxesis (.pi., iris, a-£.s-c, growth), thickening or growth of the iris from exudation into its substance. Iridoncosis (*pif, iris, and .yx3f, tumour), a name formerly proposed by Von Ammon for the same morbid state of the iris, as that to which he has since given the name Iridauxesis; but now applied to an abscess of the Iridectomia (i>if, iris, ex, out, te>v_>, to cut), operation for artificial pupil by excision. . . Iridectomedialysis (.pu, iris, Ix, out, te^vo, to cut, ..aXi/--.?, separation), operation for artificial pupil by a combination of excision and separation. Iridencleisis (ipi., iris, iv, in, and xXe.<_, to close), the strangulation of a prolapsed portion of the iris between the lips of an incision in the cornea in certain operations for artificialpupil. Iridodialysis (-?axo;, a lens or lentil), inflammation of the uvea and anterior wall of capsule of the lens. Keratitis (xlga?, horn, cornea), inflammation of the cornea. Keratonyxis (xlfac, cornea, viglt, a puncture), corneal puncturation in needle operations for cataract. Korectomia. See Corectomia. KOREDIALYSIS. See COREDIALYSIS. Koromorphosis. See Coromorphosis. KOREPLASTICE. See COREPLASTICE. Korotomia. See Corotomia. Lagophthalmos (Xay.j, a hare, o.aX/txoj, fa eye), oculus leporinus, or hare's eye. Retraction or shortening of either eyelid. Leucoma (Xe.x..», to transform, o^if, vision), distorted appear- ance of objects. Microphthalmos (/-uxj.f, small, .^.aXj-t-?, the eye), smallness of the eye from imperfect development. Micropy (j_t.»xfo., small, o^it, vision), a state of vision in which objects appear smaller than natural. Milium (a millet seed), a small white tumour of the eyelids or their neigh- bourhood. Monoblepsis (/otovof, single, j-Xe^j?, view), state in which vision is distinct only when one eye is used. Mucocele (-t-|a, mucus, x«Xw, a tumour), dropsy of the lachrymal sac. Musc_e volitantes (musca, a fly, volito, to fly about), the appearance of grayish motes before the eyes. Mydriasis (aftvtyo;, obscure, or /xv^ien, to abound in moisture, because it was supposed to be owing to redundant moisture), preternatural dilatation of the pupil. Myocephalon (juuia, a fly, xs.aX/t*.?, eye, ._ov>i, pain), pain in the eye. Ophthalmology (o_aX/uo?, eye, X.yoj, a discourse), the science of ophthal- mic medicine and surgery. Ophthalmoplegia (.$_aX/_..?, eye, n\nyh, a blow or stroke), paralysis of the muscles of the eyeball. Ophthalmoptosis (o-\,, fa eye), preternatural acuteness of vision. Pacheablephara, Pachytes (wa;t-T»., thickness, from wa^.j, thick, 0\iX-XTaiva, a vesicle, from <}>x_£_i, to gush forth), vesicle filled with a watery fluid. Photophobia (3?, light, foBtv, to dread), intolerance of light. Photopsia (_Jf, light, o^it, vision), subjective appearance of light before the eyes. Phtheiriasis (9Eif, a louse), pediculi among the eyelashes and hairs of the eyebrows. Pinguecula (pinguis,/o.), a small tumour on the white of the eye near the edge of the cornea, apparently but not really adipose. Pladarotes (irXaXaeh, flaccid), thickening of the palpebral conjunctiva. Presbyopy (irfeo-Bvs, old, Si^, the eye), farsightedness. Proptosis (itp, before, wjwi?, a falling down, from wiwt<_, to fall); see Ophthalmoptosis. Psorophthalmia (^o-pa, scabies, o9aXn*.?, the eye), ophthalmia tarsi. Pterygium (wTep.v, a wing, wTEjuyiov, a small wing), thickened and vascu- lar state of a portion of the conjunctiva, of a triangular shape, the apex encroaching more or less on the cornea. Ptilosis (wnX-xri?, bald), falling out of the cilia; see Madarosis. Ptosis (irrZtrt;, a falling down, from mmeo, to fall), falling down of the upper eyelid. Pupil (pupilla), the aperture in the iris. Retinitis (rete, a net), inflammation of the retina. Rhexis, or Rhegma Oculi Q .£i. and phyfAa, a rupture), rupture of the eyeball. . Rhytidosis (pvrfitetrit, a wrinkling, from p.Ti.o_), to wrinkle), collapsed or contracted state of the cornea. Sclerotitis (a-xXwj.?, hard,) inflammation of the sclerotica. Scotomata (o-xoTuifM, dizziness, from o-xoto'd., to darken), dark spots seen before the eyes; see Musc_e Volitantes. Staphyloma (o-rauX«, a grape,) a projection of some part of the eyeball, generally of the cornea and iris, or sclerotica and choroid. Staphyloma Racemosum (racemus, a bvmch of grapes), staphyloma is so called when there is an appearance of several projections. Stenochoria ((Tr-vo^a-eia, narrowness of space, from o-t-voj, narrow, ^o(, space), a contraction; applied to the derivative lachrymal passages. 486 GLOSSARY. Stereoscope (trrsftls, solid, and a-xanitu, I look at), the instrument described at § 1915. Stillicidium (stillo, to drop, cado, to fall), dropping of tears from the eye, in consequence of obstruction of the derivative lachrymal passages. Strabismus (_-rfa/-.£_>, to squint, from a-r^agos, twisted), squinting. Symblepharon (*gov, eyelid), adhesion of the eyelids to the eyeball Synchesis (trvyxyo-is, mixture, from o-.v, together, and xioo, to pour), dissolu- tion of the vitreous body. Synechia (o-wi^eia, continuity, from a-wi^m, to keep together), adhesion of the iris to the cornea or capsule of the lens; in the former case it is distin- guished as anterior synechia, in the latter as posterior synechia. Synizesis (_-_.iJ.--ic, a falling together, from _-_..£._>, to set together), closure of the pupil. Tarsoha_>hia (ra^o-of, tarsus, ga$>), a suture), suture of the tarsal margins in ectropium of the external angle. Taraxis (-rafa^if, disturbance, from raeaa-e-ie, to disturb), slight external ophthalmia. Trachoma (i-gap^a, roughness, Tja^o_), to make rough), granular conjunc- tiva. Trichiasis (&ex% a hair), inversion of the eyelashes. Trichosis (9fi£, a hair), Trichosis Bulbi, a small tumour on the front of the eyeball, with hair growing from it. Tylosis (t.Xoj, callosity), thickening and induration of the borders of the eyelids. Xeroma, Xerophthalmia, Xerosis (%vel(, dry), dryness of the eye, of which there are two kinds, viz: conjunctival and lachrymal. INDEX. [The Numbers refer to the Sections.] Abscess of anterior chamber, 1055-1062 cornea, 335, 996 iris, 376, 814 lachrymal caruncle, 2357-2358 lachrymal sac, 2407-2409, 2423-2425 Meibomian glands, 2111-2112 orbit, 2528-2537 Abscission of iris, 1575 Absorption, cure of cataract by, 1277, 1454, 1461, 1496 of orbit from pressure, 2545 Accidental or complementary colours, 1753 Acetate of lead precipitated on ulcerated conjunctiva and cornea, 999-1000 Acute inflammation, 261-265 Adaptation of an artificial eye, 1098-1110 Adhesion, healing by, 224, 246, 249, 252 Adjustments, optical, of the eye, abnormal states of, 1605-1686 Albugo, 1004-1006 Amaurosis, 1757, 1784-1872. apoplectic, 1939 hydrocephalic, 1828, 1841 from congestion or inflammation of nervous optic apparatus, 1814, 1826, 1845, 1847 causes of, 1813, 1814, 1843 considered nosologically, 1784-1821 pathologically, 1822-1843 therapeutically, 1844-1872 definition of, 1784 diagnosis of, 1238-1239, 1815-1818 nosologically considered, 1784-1821 pathologically, 1822-1843 therapeutically, 1844-1872 from aneurism of central artery of retina, 1835 apoplexy of eye, 1833, 1S68, 1870 blows on eye, 509, 1366 cerebral congestion, 1839 concussion of retina, 2594, 2595 or other injury of the head, 2596 depressed or reclined lens, 1451, 1492 disease in antrum, 1828 of frontal sinus, 1828 disordered digestive organs, 1854 dropsy of the eye, 1123-1143 encephalic aneurism, 1841 enlarged pituitary gland, 1841 exostosis of orbit, 1838 488 INDEX. Amaurosis from fractured cranium with depression, 1841 hemorrhagy, 1835, 1841 hydrocephalus, 1828, 1841 inflammation of orbital cellular membrane, 2530 posterior tunics of the eye, 867, 873, 1830 injuries of branches of fifth nerve, 2596 intense light, 1832, 1854, 1866 intoxication, 1854 irritation of branches of fifth nerve, 1854 laceration of retina, 1832 lightning, 1366 loss of fluids, 1862 masturbation, 1862 morbid changes aifecting membranes or bones of cranium, 1828, 1838 in optic nerves, 1835 formations in brain, 1841 onanism, 1862 ophthalmia interna posterior, 867, 873, 1830 over exercise of sight, 1854, 1866 pressure on eye, 1828, 1835, 1841, 1868, 2545 sanguineous extravasation in head, 1839, 1841 spermatorrho_a, 1862 suckling, 1862 suppressed menses, 1854 perspiration, 1854 purulent discharge, 1854 tumours in brain, 1841 orbit, 1828, 1838, 2545 venery, 1862 worms, 1854 wounds of eye, 2594-2597 wounds of eyebrow or eyelids, 2595-2596 degrees of, 1785-1787 lactantium, 1862 prognosis in, 1819-1821, 1855, 1863, 1871 seats of, 1822, 1841 symptoms of, 1793-1807, 1847-1852, 1858-1862 traumatica, 2594-2596 treatment of, 1844-1872 with debility, 1858-1865 postfebrile ophthalmitis, 958-964 Amblyopy, or incomplete amaurosis, 1699, 1785, 1786 Anchyloblepharon, 2252-2265 Anel's probes, uses of, 2455-2459, 2472-2474 syringe, injections with, 2427, 2433 Aneurism by anastomosis in orbit, 2567-2569 of eyelids, 2300-2303 of central artery of retina, 1835 cerebral arteries, a cause of amaurosis, 1828, 1841 ophthalmic artery, 1828, 1835 Angles of eye, exploration of, 39-41 Anterior chamber, abscess of, 1055-1062 Antrum, pressure on orbit from, 2547 disease of, causing amaurosis, 1828 Apoplexy, amaurosis from, 1841 of eye, 1833, 1870 Applications to the eyes, cold, 110-112 INDEX. 489 Applications to the eye, warm, 113-114. Aqueous chambers, dropsy of, 1063-1065, 1123-1143 foreign bodies in, 2626-2628 humour, evacuation of, 176, 444 loss of, 2610 Aquo-capsulitis, 763-781 Arcus senilis, 68, 1310 Arthritic ophthalmia, 829-851, 891, 921 ring, 68-71, 764,831 Artificial dilatation of the pupil, 100-102 eye, 1098-1110 pupil, 1501-1582 by excision, 1535-1550 incision, 1514-1534 separation, 1552-1574 compound operations for, 1580-1582 general conditions for, 1505-1513 states of eye requiring, 1580-1582 Asthenopy, 1691-1705 Atresia iridis, 369-372 of lachrymal puncta, 2455-2469 Atrophy of eye, 1089-1095 Atropia, solution of sulphate of, 101, 128 Beer's cataract knife, 1320 Belladonna, uses of, 100-102, 435-439, 1009, 1122, 1296 Blear eyes, 2089 Bleeding, general, in ophthalmic inflammation, 93, 421-426 local, 442, 443 Blennorrhcea of derivative lachrymal organs, 2416-2430 Blepharitis scrofulosa, 2081-2103 Blepharospasmus, or spasmodic closure of the eyelids, 19 Blood in inflammation, changes in, 216, 222 corpuscles, accumulation and stagnation of in the relaxed and dilated vessels in inflammation, 184-193 effused into eye, &c, 1144-1148, 2651, 2657 vessels, arrangements of, in ophthalmia;, 62, 63 state of, in inflammation, 179-183 Blows on eye, 1366, 2594-2599 Bluish-white ring round the cornea, 68-71, 764, 831 Brain, morbid formations in, producing amaurosis, 1839 Buffy coat of inflammatory blood, 222 Burns of cornea, 2589-2593 eyelids, 2671-2674 Bursting of eye, from blows, 2651-2652 Calculus, lachrymal, 2524 Meibomian, 2272 Callosity, scirrhoid, of eyelids, 3304-2306 Cancer of eyeball, 1165 eyelids, 2307-2319 soft, of eyeball, 1166-1190 Canthi, exploration of, 39-41 CaDSule, aqueous, inflammation of, 346-347, __., 7b_, 781 tP crystalline, inflamed, 380, 388-392, 852-859 injuries of, 2637-2649 Carbuncle of eyelids, 2063-2065 ...... , - -0,Q „-c- Caruncula lachrymalis and semilunar fold, chronic enlargement of, 2359-2363 fungus of, 2364, 2365 490 INDEX. Caruncula lachrymalis, inflammation of, 2350 polypus of, 2364-2365 scirrhus of, 2366 Caries of orbit, 2168, 2538, 2544 os unguis, 2425 Cataracta cum zonula, 1273 cystica, 1275, 1276, 2645 lymphatica, or false cataract, 1214 pyramidata, 1214,1251 tremulans vel natatalis, 1275, 2645 traumatica, 393, 2637-2640 Cataract, 1211-1496 anterior capsular, 1251-1257 black, 1223 capsular, 1250-1261 capsulo-lenticular, 1262-1272 causes of, 1237, 1247, 1255, 1265, 1270 central, 1251, 1265-1267 complications of, 1281-1286 congenital, 1265, 1269, 1486-1488 couching of, 1402-1453 cure of, by absorption or dissolution, 1277, 1454-1485 operation, 1277 definition of, 1211 depression of, 1402-1453 diagnosis of, 1216-1221, 1238, 1248, 1256 displacement of, 1402-1453, 1492 division of, 1454-1485, 1496 examination of cases of, 99, 103-105, 1216 et seq. extraction of, 1308-1401 fibrinous, or false cataract, 1214 firm, or hard, 1222 fluid, 1270, 1456 genera and species of, 1212 glasses, 1497-1500 green, 1885-1887 hard, 1222 history of pathology of, 1875 lenticular, 1215-1249 Morgagnian, 1270 operations for, 1277 pigmentous, 1214 position of patient in operations for, 1298 posterior capsular, 1258-1261 prognosis in, 243, 1241, 1249, 1257, 1261, 1278 purulent, or false cataract, 1214 reclination of, 1402-1453 sanguineous, or false cataract, 1214 secondary, 1489-1490 Biliquose, 1273, 1392-1394 soft, 1243-1249, 1456 spontaneous displacement of, 517, 1275, 2641-2649 trabecular, 1214 treatment of, without operation, 1277 questions regarding removal of, by operation, 1278-1291 Cataracts from inflammation, 1214, 1255 spurious, 1214 true, 1214 INDEX. 491 Catarrhal ophthalmia, 453-483 Catarrho-rheumatic ophthalmia, 728-742 Cataplasms to the eyes, warm, 113 Catgut, as a means of dilating the nasal duct, 2502-2505 Catoptrical examination of the crystalline body, 104, 105 Cat's eye, 1898-1900 Cautery, potential, application of to the eye, 140 Cellular membrane of orbit, induration of, 2528 infiltration of, 26 85 inflammation of, 1525-2537 Celsus's operation for lagophthalmus, 2134-2135 summary of ophthalmic medicine, and surgery, Introduction Cerebral congestion causing amaurosis, 1839 Chalazion, 2289-2296 Changes in the blood in inflammation, 216-222 Chemosis, 60, 152, 308, 504, 530, 551 excision and incision of conjunctiva in, 152 Cheselden's operation for artificial pupil, 1516-1524, 1603 Choroid, non-malignant tumours of, 1159-1164 wounds of, 2651 Choroiditis, 381-384, 866-921 Chromatic vision, 1687-1688 Chronic inflammation, 261-265 Chroopsy, 1736-1742 Cicatrices, eversion of lids from, 2131-2168 of cornea, 360-361, 1007-1010 Cilia, exploration of, 16 inversion of, 2198-2225 Cirsophthalmia, 1076-1086 Coarctation of retina, 1142 Coat, buffy, of inflammatory blood, 222 Cold applications to the eyes, 110-112 lotions, 110 douche bath, 111 dry, 112 Collyria, 119-128 dry, 138-139 Coloboma iridis, 97, 1593-1661 palpebral, 2664 Coloured vision, 1688 Colours, accidental or complementary, 1752-1756 Complementary colours, 1752-1756 Compound ophthalmia;, 696-742 Concussion of brain, a cause of amaurosis, 2595 Congestion, in inflammation, 179-185, 213 Conical cornea, 1111-1122 hyrophthalmia, 1111-1122 Conjugate foci, 1629 Conjunctiva arida, 991-995 chemosed, excision and incision of, 152 corneae, inflammation of, 341-347, 710 cuticular, 991-995 diseases of, 2322-2347 excision and incision of, in chemosis of, 152 foreign substances adhering to, 156-174 in folds of, 163 oculo-palpebral space of, 156-174 granular. 38, 311, 983-990 492 INDEX. Conjunctiva, inflammations of, 300, 322, 451-588 injuries of, 2571-2593 polpyus of, 2343 scarification of, 147-150 tumours of, 2336-2338, 2343-2345 warts of, 2343 Conjunctival surface of eyelids, exploration of, 34-38 Conjunctivitis catarrhalis, 453-483 contagiosa, 484-533 Egyptiaca, 484-533 erysipelatosa, 312-313, 571-579 gonorrhoica, 557-570, 798 leucorrhoica, 543 morbillosa, 938-943 phlyctenulosa, 619-665 puro-mucosa, 451-452 pustulosa, 580-588 scarlatinosa, 938-943 scrofulosa, 619-665, 697-727 variolosa, 944-957 Contagious ophthalmia, 484-533 reproduction of by inoculation, as a means of treating pannus, 515, 1015 Contusion of cornea, 259 edge of orbit, 2595 eyebrow and eyelids, 2656-2659 Convulsions of eyeball, 2034-2036 eyelids, 19 Corectomia, 1535-1551 Coremorphosis, 1501-1582 Coreoncion, Graefe's, 1560, note Langenbeck's, 1560, note Coreplastice, 1501-1582 Cornea, abscess of, 335-337, 996 arthritic ring round, 68-71, 764, 831 bluish-white ring round, 68-71, 764, 831 burns of, 2589-2593 cicatrice of, 360-361, 1007-1010 conical, 1111-1122 contusion of, 259 dimple or clear facet of, 361 extraction through, 1308-1401 fistula of, 2618 foreign substances adhering to, 156-175 imbedded in, 2601-2606 hernia of, 351-354, 2610 inflammation of, 328-363, 613-618, 2616, 2620-2625 injuries of, 2601-2625 lining membrane of inflamed, 330, 346, 763 malformations of, 1111, 1132, 1680-2183 non-malignant tumours of, 459, 1159-1164, 2340-2345 paracentesis of, 176 penetrating wounds of, 2609-2619 punctured wounds of, 2609-2619 rupture of, 508 specks or opacities of, 1001-1011 ulcer of, from debility, 997 ulcers of, 348, 350, 997-1000 INDEX. 493 Cornea, vascular, 1012-1015 and iris, staphyloma of, 1020-1049 wounds of, 2602-2606 Corneitis parenchymatosa, 666-695 scrofulosa, 666-695 Corodialysis, 1552-1574 Corotomia, 1514-1534 Couching, 1402-1453 Counter-irritation in diseases of the eyes, 153-154 Crampton's operation for entropium, 2194-2197 Cranium, disease of membranes or bones of, producing amaurosis, 1828, 1841 pressure on orbit from cavity of, 2547 Crystalline lens and capsule, injuries of, 2637-2649 Crystallino-capsulitis, 388-393, 852-859 Cupping, in diseases of the eyes, 141 Cuticular conjunctiva, 991-995 Cylindrical eye, 1680-1683 Cysticercus or hydatid in anterior chamber, 1149-1158 eyelid, 2299 under conjunctiva, 2346 Dacryocystitis acuta, 2404-2415 chronica, 2416-2430 Dacryolites, 2424 Daviel's operation for cataract, Introduction Day-blindness, 1777 Debility, amaurosis with, 1858-1872 Depression of cataract, 1402-1453 through cornea, 1434-1453 sclerotica, 1408-1433 Descemet, inflammation of membrane of, 330, 346, 763 Dichromatism of lens in glaucoma, 1878-1879 Digestive organs, amaurosis from disordered, 1854 Dilatation of orbit from pressure, 2545 pupil, artificial, 100-102 Dimple, or clear facet of cornea, 361 Diplopy, 1940-1952 with one eye, 1689-1690 Direction of the eyeballs, examination of, 47, 48 Dislocation of eyeball, 265 lens, 2641-2649 pupil, 1503, 1575-1579 Displacement of cataract, 291, 1402-1453, 1491-1496 pupil, 878, 2632 Dissolution of vitreous body, 1087-1088 Distichiasis, 2199-2225 Distoma in crystalline, 1158 Distortion of eyeball, 1953-2036 Division of cataract, 1454-1485, 1496 through cornea, 1469-1485 sclerotica, 1462-1468 enlarged vessels in sclerotic conjunctiva, 151 Double vision from want of correspondence in muscles of eyeball, 1940-1952 with one eye, 1689-1690 two eyes, 1940-1952 when natural, 1927 Drilling, an operation for cataract, 1481-1485 Drops for the eyes, 119-128 Dropsy of aqueous chambers, 1063-1065, 1123-114. 494 INDEX. Dropsy of eye, 1123-1143 vitreous body, 1077, 1135-1140 sub-choroid, 1077, 1142-1143 sub-sclerotic, 1077, 1142-1143 Dry cold to the eyes, 112 collyria, 138-139 warmth, 116-117 Dryness of eye, 991-995, 2369-2372 Duct, nasal, injuries of, 2682 obliteration of, 2520-2523 obstruction of, 2493-2519 Ducts, lachrymal, injuries of, 523, 2194, note, 2675 Dura mater, and cranium, disease of, producing amaurosis, 1828, 1841 Ecchymosis of eyelids, 2656-2659 under conjunctiva, 60, 1147, 2657 Ectropium, 17, 2117-2170 sarcomatosum, 2117, 2119-2130 Effusion of blood into eye, 1144-1148 Egyptian ophthalmia, 484-533 reproduction of, by inoculation, as a means of treating pannus, 515, 1015 Emetics in ophthalmic inflammation, 431 scrofulous ophthalmia, 653 Emphysema of eyelids, 23, 2681 subconjunctival, 60 Encanthis benigna, 2359-2363 inflammatoria, 2350 maligna, 2366 Encysted tumour in connection with the iris and aqueous chambers, 1164 tumours in orbit, 2545-2570 eyelids and eyebrows, 2271-2319 Enlarged vessels in sclerotic conjunctiva, division of, 151 Enlargement of lachrymal gland, 2384-2386 Enlargements of eyeball, 1111 Entozoa in organs of vision, 1149-1158, 2299, 2346-2347 Entropium, 429, 2171-2197 Epicanthus, 2251 Epiphora, 46, 2373-2375 Eruptions, syphilitic, affecting eyelids, 2113-2116 Erysipelas of eyelids, 401, 22, 2046-2060 Erysipelatous ophthalmia, 312-313, 571-579 Evacuation of aqueous humour, 176, 444 Eversion of eyelids, 17, 2117-2170 Evulsion of eyeball, 2655 eyelashes, 155 Examination of the eyes, objective, 5 subjective, 2 direction and movements of the eyeballs, 47, 48 front and interior of the eyeball, 49 state of pupil, 92-98 catoptrical, of crystalline body, 104-105 Excision, artificial pupil by, 1535-1550 of chemosed conjunctiva, 152 Exciting cause of inflammation, mode of action of, 194-201 Excoriation, eversion of eyelids from, 2119-2130 Excrescence of iris, fungous, 1159, 1164 Exophthalmia, 2545 INDEX. 495 Exophthalmos, 2545 Exostosis of orbit, 2546 Exploration of the angles of eye and lachrymal organs, 39-46 conjunctival surface of eyelids and palpebral sinuses, 34- 38 eyes, in order to a diagnosis, 1-109 objective, 5-109 subjective, 2 eyebrows and orbital margins, 12-15 eyelids, tarsal border, cilia and Meibomian aperture-, 16-33 Extirpation of eyeball, 1196-1210 eyelids, 2315-2317 lachrymal gland, 2382-2390 orbital tumours, 2557-2563 partial, of orbital tumours, 2557 Extraction of cataract, 1308-1461 through sclerotica, 1308 section of one-third of cornea, 1392-1456 semicircular section of cornea, 1319 Exudation in inflammation, 203-205 Exuded matter in inflammation, 235-238 absorption of, 239 development of organic elements in, 240- 242 Eye, adaptation of artificial, 1098-1110 apoplexy of, 1833, 1870 blows on, 1366, 2594-2599 cylindrical, 1680-1683 dropsy of, 1123-1143 gunshot wounds of, 2599 modes of fixing, during operations, 1298-1307 pressure on, 1828, 1841, 1868-1872, 2545 sanguineous effusion into, 1144-1148, 2651, 2657 Eyes, sensations of the two, correspondence between, 1902-1908 loss of correspondence between, 1940-2036 Eyeball, atrophy of, 1089-1095 bursting of, 2651 cancer of, 1165, 1166-1190 convulsions of, 2034-2036 dislocated, 265 enlargements of, 1111 evulsion of, 2655 extirpation of, 1196-1210 fungus hasmatodes of, 1166-1190 immovable distortion of, 1953 inflammatory diseases of, 177, 291, 450 injuries of, 2594-2655 malignant affections of, 1165-1195 melanosis of, 1191-1195 oscillation of, 2034-2036 scirrhus of, 1165 encephaloid or medullary tumour of, 1166-1190 tumours within, 1159-1164 Eyeballs, movements of the two, correspondence in, 1928-1939 loss of correspondence in, 1940-2036 Eyebrow, injuries of, 13, 2595, 2596, 2660-2666 phtheiriasis of, 2320-2321 496 INDEX. Eyebrow, wounds of, 2545, 2656-2659 Eyebrows and orbital margins, exploration of, 12-15 Eye-drops, 119-128 Eyelashes, exploration of, 16, 29-31 false, 30, 31. 2199 inversion of, 2198-2225 Eyelid, lower, capable of being drawn up over the front of the eyeball, 18 retraction of, 2226-2238 upper, falling down of, 20, 2239-2250 Eyelids, albuminous tumour of, 2284 aneurism by anastomosis of, 2300-2303 burns and scalds of, 21, 2671-2674 callosity, scirrhoid, of, 2304-2306 cancer of, 2307-2319 carbuncle of, 2063-2065 contusion and ecchymosis of, 2656-2659 convulsion of, 19 emphysema of, 23, 2681 encysted tumours in, 2297-2298 erysipelatous inflammation of, 2046-2060 eversion of, 2117-2170 exploration of, 16-38 extirpation of, 2315-2318 fibrinous tumour of, 2289-2290, 2292-2296 hydatids in, 2299 inflammation of edges of, 2070, 2071 injuries of, 2656-2674 inversion of, 2171-2197 malignant pustule of, 2063-2069 melanosis of, 2319 milium of, 2280-2283 na;vus maternus of, 2300-2303 _dema of, 23 palsy of, 2228-2234, 2239-2250 phlegmonous inflammation of, 2037-2045 phlyctenula of, 2275 poisoned wounds of, 2667, 2670 retraction of, 2226-2238 scirrhoid callosity of, 2304-2306 scirrhus of, 2309-2319 spasm of, 19 syphilitic ulceration of, 2113-2116 eruptions affecting, 2116 tumours in, 2271-2299 twitching or quivering of, 19 warts on, 2276-2277 wounds of, 2656-2674 Eye-powders, 138 Eye-salves, 129-137 Eye-waters, 119-128 Farsightedness, 1658-1679 Fifth nerve, injuries of branches of, 2596 irritation of, producing amaurosis, 1854 Filaria in crystalline, 1158 Medinensis under conjunctiva, 2347 First intention, healing by, 246-252 Fistula of cornea, 2618 INDEX. 497 Fistula of lachrymal sac, 2444-2448 spurious, 2398 true lachrymal, 2381 Fixed muscae, 1778-1783 Foci, conjugate, 1630 Focus, principal of a lens, 1628 Fomentations to the eyes, warm, 113 Foreign bodies in aqueous chambers, 2626-2628 in oculo-palpebral space of conjunctiva, 156-175 body in orbit, 2687-2688 substances adhering to conjunctiva, 156-174 imbedded in cornea, 2601-2606 Fractured cranium with depression, producing amaurosis, 1841 Fractures of edge of orbit, 15 Front of the eyeball, examination of, 49-56 Frontral sinus, diseases of, produce amaurosis, 1828 pressure on orbit from, 2547 Fungus haematodes in the orbit, 2565 of brain, 1182 eyeball, 1166-1190 optic nerve, 1182 Fungus of caruncula lachrymalis, 2364-2365 iris, 1159 Gerontoxon, 1310, note Gibson's mode of extracting soft cataract, or combination of division and extraction, 1456, 1496 Gland, lachrymal, encysted tumour in, 2382 enlargement or scirrhus of, 2382-2390 extirpation of, 2382-2390 fistula of, 2381 inflammation and suppuration of, 2376-2380 injuries of, 2675-2676 Glands of cilia, inflammation of, 2081-2103 Glanduhe congregatae or lower mass of lachrymal glands, injuries of, 2194 note, 2675 inflammation of, 2376-2380 Glasses for cataract-patients, 1497-1500 longsightedness, 1658-1679 shortsightedness, 1638-1657 Glaucoma, 1873-1897 acute, 1897 dichromatism of lens, in, 1878-1880 dissections of eyes in state of, 1879 its diagnosis from cataract, 1239 with amaurosis, 1888-1897 with cataract, 1895-1896 Gonorrhoeal conjunctivitis, 557-570 iritis, 798 ophthalmia, 557-565 Grando, 2287-2296 Granular conjunctiva, 38, 311, 983-990 Granulation, healing of a wound by, 224, 246, 2o3-254 Gunshot, wounds of the eye, 2599 Gutta opaca, see cataract serena, see amaurosis Ha-mophthalmus, 1144-1148 32 498 INDEX. Half-vision, 1762-1767, 1787 Healing of a wound, 246-256 by first intention, 246-252 by second intention, 246, 253-255 Healing process, nature of, 223-226 Hemeralopia, 1768 Hemiopy, 1762-1767, 1787 Hernia of cornea, 351-354, 2610 iris, 351-354 lachrymal sac, 2431-2435 Himly's operation for artificial pupil, 1576-1579 Hordeolum, 2104-2110 Hyaloid membrane, dissolved, 1087-1088 opacities of, 395 Hyaloiditis, 395, 866 Hydatids in eyeball, 1149-1158 eyelids, 2299 orbit, 2564 under conjunctiva, 2346-2347 Hydrocephalus, amaurosis from, 1828, 1841 Hydrophthalmia, 1123-1143 Hydrops of lachrymal sac, 2437-2443 Hyperkeratosis 1111-1122 Hyperostosis of orbit, 2546 Hypertrophia lentis, 1896 Hypochyma, 1874 Hypopyon,1055-1062 Incision, artificial pupil by, 1514-1534 of chemosed conjunctiva, 60, 152, 308, 504, 530, 551 through cornea, artificial pupil by, 1525-1534 sclerotica, artificial pupil by, 1516-1524 Infiltration of orbital cellular membrane, 2657, 2685 Inflammation, changes in the blood in, 216-222 distinction of into acute and chronic, 261-265 from section or disease of the nerves of a part, 199-201 in general, 178 mode of action of exciting cause of, 194-201 mode of action of remedies in, 284-290 modifications of, according to tissue affected, 268-280 exciting cause, 281 state of constitution, or existence of constitutional disease, 282 of aqueous capsule, 763-781 bones of orbit, 500, 2538-2544 caruncula lachrymalis, 2350 choroid, 382-384, 866, 869, 873 conjunctiva, 98, 300-322, 451-588 cornea, 328-363, 613-618 crystalline lens and capsule, 388-393, 852-859 derivative lachrymal organs, acute, 2404-2415 chronic, 2416-2430 edges of eyelids, 2070-2103 eyelids, erysipelatous, 22, 2046-2060 phlegmonous, 2037-2045 hyaloid membrane, 395, 866 internal nptic apparatus, a cause of amaurosis, 1813, 1814, 1824 1827,1846-1872 INDEX. 499 Inflammation of iris, 364-380,782-851 lachrymal gland, 2376-2380 Meibomian follicles, 2111-2112 non-vascular parts, 206-215 orbital cellular membrane, 2525-2537 periosteum of orbit, 2538-2544 retina, 381-386, 860-921 semilunar membrane, 2350-2356 ophthalmic, 177 in general, 291-298 proper, 179-183 resolution of, 243-245 terminations or events of, 223-260 varieties of, 261-283 Inflammations of eye from injuries, 970-9S2 eyeball, 450-982 Inflammatory process, phenomena attending the first step of, 179-183 Injections of lachrymal passages, 123, 2427, 2433 Injuries of branches of fifth nerve, 2596 conjunctiva, 2571-2593 cornea, 2601-2625 crystalline lens and capsule, 2637-2649 eyeball, 2594-2597 eyebrow and eyelids, 2656-2674 head, amaurosis from, 1841, 2595 iris, 2629-2636 lachrymal canals, 2678-2679 glands and ducts, 2675-2676 sac, 2680-2682 muscles of eyeball, 26S5 nasal duct, 2682 orbit, 2595, 2683-2688 orbital cellular membrane, 2685 Inoculation to reproduce contagious ophthalmia, as a means of curing pannus, 515, 1015 Interior of eyeball, examination of, 49-56 Intolerance of light, 4, 8, 406, 408 Intoxication producing amaurosis, 1854 Inversion of eyelashes, 2198-2225 eyelids, 2171-2197 Iriankistron, Schlagintweit's, 1560 note Iridauxesis, 1071-1075 Iridectomy, 1535-1551 Iridectomedialysis, 1571 Irideremia congenita, 98, 1583—1592 Irido-dialysis, 1552-1574 Iridoncosis, 84, 1071-1075 Irido-periphakitis, 852-859 Iridoschisma, 1593-1661 Iridotomy, 1514-1534 Iris, abscess of, 376, 814 abscission of, 1575-1579 accidental separation of, from its ciliary attachment, 2630, 2631 congenital absence of, 98, 1583-1592 fissure of, 97, 1593 imperforation of, 1603, 1604 encysted tumour connected with the, 1164 fungous excrescence of, 1159-1163 500 INDEX. shern:n of, 351-354 inflan,.T;_v.<.m of, 364-380, 7S2-851 injuries of, 2629-2636 its motions effected through third nerve and sympathetic, 1607-1618 non-malignant tumours of, 1159-1164 paralysis of, 1605-1626 preternatural states of, 1583-1626 prolapsus of, 362-363, 1017-1019, 2610-2616 staphyloma of, 1071-1075 tremulous, 1087 Iritis, 364-380, 782-851 after typhus fever, 958 arthritica, 829-851 gonorrhoica, 798 rheumatica, 787-810 scrofulosa, 7S4-786 sympathetica, 970-982 syphilitica, 811-828 traumatica, 970-982 with amaurosis after typhus fever, 958-964 Irritation of fifth nerve, amaurosis from, 1854 Jaeger's (F.) operation for ectropium, 2150-2160 Janin's ointment, 136 operation for artificial pupil, 1527 Kepler explains effects of glasses, Introduction Keratitis, see Corneitis Keratonyxis, 1403, 1424-1453 Lachrymal calculus, 2524 canals, injuries of, 2678, 2679 obstruction of, 2455-2469 fistula, true,(23Sl glands and ducts, injuries of, 2675 enlargement or scirrhus of, 2384-2390 encysted tumour in, 2382 . extirpation of, 2382-2390 inflammation and suppuration of, 2376-2380 organs, acute inflammation of derivative, 2404-2415 chronic inflammation of derivative, 2416-2430 caruncle, inflammation of, 2350-2356 abscess of, 2357-2358 organs, diseases of derivative, 2391-2524 secreting, 2367-2390 exploration of, 39-46 puncta, obstruction of, 2451-2469 relaxation of, 2449-2450 sac, abscess of, 476, 2407-2409, 2423-2425 blennorrhoea of, 2416-2430 dropsy of, 2437-2443 fistula of, 479, 2398, 2444-2448 hernia of, 2431-2436 injuries of, 2680-2682 mucocele of, 2437-2443 polypus of, 2492 relaxation of, 2431-2436 spurious fistula of, 2398 INDEX. 501 Lachrymal xeroma, 2369-2372 Lachrymation, disordered, 396, 2367-2375 Lactation, a cause of amaurosis, 1862 Lagophthalmos, 2226, 2227 Lapis divinus, 124 Leeches, application of to the eyes, 142-145 Lens and capsule, injuries of, 2637-2649 dichromatic in glaucoma, 1878-1879 dislocation of, 2641-2646 hypertrophy of, 1896 opacity of, 1211-1496 regeneration of, 394 Lentitis, 387-395 Leucoma, 183, 361, 1007-1010 Leucorrhoeal ophthalmia, 543 Light, amaurosis from intense, 1832, 1854, 1866 intolerance of, 4, 8, 406-408 Lime, effects of, thrown into eye, 507, 2578-2585 Lippitudo, 407, 2088, 2090 Longsightedness, 1658-1679 Luscitas, 1953, 2022 Lymph, 236 Madarosis, 2088 Masturbation, a cause of amaurosis, 1862 Maunoir's operation for artificial pupil, 1525-1534 Maxillary sinus, pressure on orbit from, 2547 Measles, ophthalmia from, 938-943 Medullary tumour of eyeball, 1166 Meibomian apertures, exploration of, 16 obliteration of, 32, 2088 obstruction of, 2271 calculus, 2272 Meibomian glands, abscesses of, 2111-2112 enlargement and induration of, 2273, 2274 Melanosis in orbit, 2566 of conjunctiva, 2319 eyeball, 1191-1195 eyelids, 2319 Menses suppressed, a cause of amaurosis, 1854 Mercury in diseases of the eye, 427-430 Mesh, as a means of dilating the nasal duct, 2494-2500 Metamorphopsy, 1951 Monoblepsis, 1950 Monostoma in crystalline, 1158 Morbillous ophthalmia, 938-943 Mortification, nature of, 257-259 Movements of the eyeballs, exploration of, 47, 48 Mucocele of lachrymal sac, 2437-2443 Muco-lachrymal muscae, 1733-1734 Muscae, fixed, 1778-1783 muco-lachrymal, 1733-1736 volitantes, 1707-1729 Muscles of eyeball, correspondence in the action of, 1928-1939 loss of correspondence in the action of, 1940-2036 injuries of, 2685 palsy of, 2020-2033 502 INDEX. Muscles of eyeball, section of in strabismus, 1987-2002, 2010-2012, 2017- 2019 Mydriasis, 1605-1606, 1624-1626, 2024 Myocephalon, 363 Myodesopsia, 1706 Myopia, 1627, 1638-1657 Myosis, 1605, 1619-1623 Myotomy, ocular, in strabismus, 1987-2005, 2010-2012, 2017-2019 Na.vus maternus of eyelids, 2300-2303 Nasal duct, injuries of, 2682 obliteration of, 2520-2522 obstruction of, 2493-2519 Nearsightedness, 328, 1627, 1638-1657 Nebula, 1004-1006 Necrosis of orbit, 2540 New vessels, development of in inflammation, 241 of cornea, 211-215, 248-251, 329, 333-334, 339, 342, 343, 346, 667, 765 of iris, 370 of crystalline capsule, 388- 392, 855 Newton's hypothesis regarding arrangement of optic nerves, 1917 Nictitation, morbid, 19 Night-blindness, 1768-1776 Nitrate of silver, application of, as a caustic, 140 drops and salve, 128, 135, 136 stains conjunctiva, 126, note Nitre in ophthalmic inflammation, 434 Non-vascular parts, inflammation of, 206-215 Nostril, pressure from, on orbit, 2547 Nyctalopia, 1768-1776 Nystagmus, 2034-2036 Obliteration of pupil, 369-371, 1069 Obstruction of lachrymal canals, 2455 Meibomian apertures, 2271 na'sal duct, 2493-2519 puncta lachrymalia, 2455-2469 Ocular myotomy in strabismus, 1987-2005, 2010-2012, 2017-2019 spectra, 1749-1756, 1730-1732 Oculo-palpebral space of conjunctiva, foreign bodies in, 156-175 (Edema of eyelids, 23 subconjunctival, 60, see chemosis Onyx, 180, 336, 996 Opacities of cornea, 1001-1011 hyaloid, 395 Opacity of crystalline capsule, 1250-1275 lens, 1215-1249 Operation for anchyloblepharon, 2260-2265 cataract, choice of an, 1491-1496 symblepharon, 2269, 2270 Operations for artificial pupil, 1501-1582 compound, 1580-1582 cataract, general account of, 1277 position of patient during, 1298 INDEX. 503 Operations for cataract, indications and contra-indications for, 1311-1314,1405, 1456 general observations and questions regarding, 1278- 1291 eversion of eyelids, 2122-2170 inversion of eyelashes, 2207-2225 eyelids, 2182-2197 Ophthalmia, aphthous, 580-588 arthritic, 829-851, 891, 921 bellica, 484-533 catarrhal, 453-483 catarrho-rheumatic, 728-742 contagious, 484-533 Egyptian, 484-533 epidemic, 467 erysipelatosa, 312-313, 571-579 externa, 450-742 from absorption of pus, 965-969 gonorrhoica, 557-565 interna, 743-982; anterior, 743-859 posterior, 860-921 Ieucorrhoica, 543 mercurial, 798 morbillosa, 938-943 neonatorum, 534-556 of new-born children, 534-556 phlyctenulosa, 619-665 puromucous, 451-452 purulenta gravior, 484-533 mitior, 453-483 of infants, 534-556 pustulosa, 580-588 rheumatica, 590-612 scarlatinosa, 938-943 scrofulous, 619-665 posterior internal, 873-890 scrofulo-catarrhal, 697-727 sympathetic, 970-982 syphilitic, 811-828 tarsi, 2070-2103 ? variolosa, 944-957, 2061-2062 Ophthalmiae, 450-982 classification of, 291-298 compound external, 696-742 diseases consequent to, 983-1097 traumatic, 970-982 Ophthalmic artery, aneurism of, 2570 inflammation, causes of, 409-414 general treatment of, by antiphlogistics, 421-439 tonics and alteratives, 440 -441 in general, 291-298 kinds of pain in, 2, 398-408 local treatment of by antiphlogistic and soothing remedies, 442-446 irritating applications, 447- 449 remedies for, 415-449 504 INDEX. Ophthalmic inflammation, treatment of, 415-449 Ophthalmitis phlebitica, 965-969 postfebrile, 958-964 puerperal, 965-969 Ophthalmo-blennorrhcea, 484-533 Ophthalmoptosis, paralytic, 2023 Ophthalmoscopy, 1—109 Optic nerves, morbid conditions of, producing amaurosis, 1835 semi-decussation of, 1766, 1913 Orbicularis palpebrarum, palsy of, 2228-2234 Orbit, abscess of, 253, 2536, 2540 absorption of, from pressure, 2545 caries of, 2168, 2538-2544 contusions of edge of, 2595 dilatation of, from pressure, 2545 diseases of, 2525-2544 exostosis of, 2546 fractures of edge of, 15 fungus haematodes in, 2565 hydatids in, 2564 hyperostosis of, 2546 injuries of, 2595, 2683-2688 melanosis in, 2566 necrosis of, 2540 osteo-sarcoma of, 2546 ostitis of, 2538-2544 penetrating wounds of, 2684-2688 periostitis of, 2538-2544 periostosis of, 256 pressure on, from cavity of cranium, 2547 frontal sinus, 2547 maxillary sinus, 2547 nostril, 2547 sphenoid sinus, 2547 within orbit, 2546 tumours in, 2546 Orbital aneurisms, 2567-2570 cellular membrane, induration of, 2528 infiltration of, 2656-2659, 2685 inflammation, erysipelatous, of, 2531 inflammation, phlegmonous, of, 2525-2537 injuries of, 2685 Oscillation of eyeball, 2034-2036 Os unguis^caries of, 2425 Osteo sarcoma of orbit, 2546 Ostitis of orbit, 2538-2544 Over-refraction, 1639-1643 Pain, kinds of, in ophthalmiae, 2, 398-408 Palpebral sinuses, exploration of, 34-38 Palsy of abductor, or external rectus oculi, 2031-2033 levator palpebral superioris, 2020, 2239-2250 muscles of eyeball, 2020-2033 face, 20, 2228 muscles supplied by portio dura, 2228-2234 third nerve, 2020-2030 orbicularis palpebrarum, 2228-2234 upper eyelid, 2239, 2240 INDEX. 505 Palsy of upper eyelid from wounds, 2243-2245 Pannus, 1012-1015 treatment of, by reproducing the purulent inflammation by inoculation, 515, 1015- Panophthalmitis, 291, 922-935 Paracentesis cornea;, 176, 444 Paralysis of iris, 1605-1626 Paralytic ptosis, 2021 divergent luscitas, 2022 ophthalmoptosis, 2023 mydriasis, 2024 Periorbitis, 2538-2544 Periostitis of orbit, 2538-2544 Periostosis of orbit, 2546 Perspiration, suppressed, causes amaurosis, 1854 Phimosis palpebrarum, 2258, 2268 Phlebitic ophthalmitis, 965-969 Phlegmon, subconjunctival, 60 Phlegmonous inflammation of eyelids, 2037-2045 Phlyctenula of eyelids, 2275 Phlyctenular ophthalmia, 619-665 Photophobia, 3, 8, 406 Photopsy, 1736-1742 Phtheiriasis, 2320-2321 Phthisis oculi, 1096-1097 Pinguecula, 2334-2335 Pituitary gland enlarged producing amaurosis, 1841 Pladarotes, 983-990 Polyopy, 16S9-1690 Polypous excrescence of lachrymal caruncle and semilunar fold, 2364, 2365 Polypus of lachrymal sac, 2492 Position of patient during operations for cataract, 1298 Postfebrile ophthalmitis, 958-964 Potential cautery, application of, to the eyes, 140 Pott's operation for cataract, Introduction Presbyopy, 1658-1678 Pressure on eye, amaurosis from, 1828, 1835, 1841, 1868, 2545 orbit, effects of, 2545 from cavity of cranium, 2546 frontal sinus, 2547 maxillary sinus, 2547 nostril, 2547 sphenoid sinus, 2547 within orbit, 2545 Principal focus of a lens, 1628 Prolapsus of iris, 362-363, 1017-1019, 2610-2616 operation of, 1576-1579 Psorophthalmv, 2081-2103 Pterygium, 2322-2333 crassum, 2327 fleshy, 2327 pingue, 2334-2335 tenue, 2327 Ptosis, 2239-2250 paralytic, 2021 Puerperal ophthalmitis, 965-969 Puncta lachrymalia, obstruction of, 2455-2469 relaxation of, 2449-2450 506 INDEX. Pupil, artificial, 1501-1582 by excision, 1535-1550 incision, 1514-1534 separation, 1552-1574 artificial dilatation of, 100-102 dislocation of, to opposite clear part of cornea, 1575-1579 displacement of, 878, 2632 examination of state of, 92-96 morbid contraction of, 1605, 1619-1623 dilatation of, 326, 1605, 1624-1626 obliteration of, 369-371, 1069 restoration of, to natural position by abscission, 1575-1579 Pupils contract during sleep, 1607 their occasional mobility in amaurosis explained, 1618 Puris, liquor, 241 Purkinje's experiment, 1730 Puro-mucous conjunctivitis, 451-452 ophthalmia in female children, with puro-mucous discharge froto. vagina, 566-570 Pus, 241 Pustular ophthalmia, 580-588 Pustule, malignant, of eyelids, 2063-2069 Quina, use of, in scrofulous ophthalmia;, 440, 656 Quivering of eyelids, 19 Reclination of cataract, 1402-1453 through cornea, 1434-1453 sclerotica, 1408-1433 Reisinger's double hook for artificial pupil, 1560, note Refraction, diminished, 1660-1664 irregular, 1605-1685 preternatural, 1639-1643 Relaxation of lachrymal sac, 2431-2436 puncta lachrymalia and canaliculi, 2449-2450 Remedies in inflammation, mode of action of, 284-290 Resolution of inflammation, 243-245 Retina, aneurism of its central artery, produces amaurosis, 1835 apoplexy of, 1833, 1870 coarctation of, 1142 laceration of, 2651 pressure on, by depressed lens, 1451 spectrum of vascular ramifications of, 1730-1731 Retinitis, 158, 381-386, 860-921 Retraction of eyelids, 2226-2238 Rheumatic iritis, 787-810 ophthalmia, 590-612 Ring, arthritic, 68-71, 764-831 bluish-white, around the cornea, 68-71, 764-831 Rupture of cornea, 508 Sanguineous effusion into eye, 1144-1148, 2651, 2657 Sarcomatous tumours in orbit, 2551-2554 Scarification of conjunctiva, 146-150 Scarlatinous ophthalmia, 938-943 Scirrhoid callosity of eyelids, 2304-2306 Scirrhus of caruucula lachrymalis, 2366 eyeball, 1165 INDEX. 507 Scirrhus of eyelids, 2307-2319 lachrymal gland, 2384-2390 Sclerotica, extraction through, 1308 non-malignant tumours of, 1159-1164 wounds of, 2651 Sclerotico-choroiditis, 870 Scleroticonyxis, 1408-1433 Sclerotitis rheumatica, 590-612 Scrofulo-catarrhal ophthalmia, 697-727 Scrofulous corneitis, 666-695 iritis, 784-786 ophthalmia, 619-665, 697-727 Secondary cataract, 1489-1490 Second intention, healing by, 246, 253-255 Semilunar fold, inflammation of, 2350-2356 Sensations of light and colour, subjective, 1736-1742 Sensations, irradiation of, 1743-1746 Separation, artificial pupil by, 1552-1574 Shortsightedness, 1638-1657 Sight, over-exercise of, a cause of amaurosis, 1859, 1866 weakness of, 1691-1705 Small-pox, ophthalmia from, 944-957, 2061, 2062 Spasm of eyelids, 19 Speck, vascular, 701, 713 Specks of cornea, 1001-1011 Spectra consequent to impressions on the retina, 1746 Spectra, ocular, 1730-1732, 1749-1756 Spectacles, concave, 1649 convex, 333, 1497-1500, 1670-1679 Sphenoid sinus, pressure on orbit from, 2547 Squinting, 1953-2019 Staphyloma, conical, 1050-1054 of cornea and iris, 1020-1049 operation for, 1043-1049 partial, 1021-1022 pathology of, 1026-1033 prevention of, 1039-1042 prophylactic treatment of, 1039-1042 spherical, 1023-1025 total, 187, 1023, 1038, 1043 iridis, 1071-1075 pellucidum, 1111-1122 posticum, 1078 racemosum, 363 sclerotic, 1076, 1086 uveae, 1071-1075 Single vision with two eyes, 1909-1926 Stereoscope, 1915 Stillicidium lachrymarum, 46, 467, 2373-2375 Strabismus, 1953-2019 convergens, 1959-2005 cure of, by ocular myotomy, or section of muscles of eyeball, 1987-2005 deorsumvergens, 2013-2016 divergens, 2006-2012 sursumvergens, 2013-2016 Strychnia, in amaurosis, 1865 Stye, 2104-2110 508 INDEX. Style, use of lachrymal, 2506-2519 Subjective symptoms, 2-4 Suckling, amaurosis from, 1862 Suffusion of cornea, 1001-1002 Sulphuric acid, effects of, thrown into eye, 2586-2588 Suppressed menses, amaurosis from, 1854 perspiration, amaurosis from, 1854 purulent discharge, amaurosis from, 1854 Suppuration, 224, 241, 246 Symblepharon, 2266-2270 Sympathetic ophthalmia, 970-982 Synchesis, 1087-1088 Synechia anterior, 1066-1068 posterior, 1066-1068 Synizesis, 1069-1070 Syphilitic iritis, 811-828 eruptions affecting eyelids of infants, 2113-2116 ulceration of eyelids, 2113-2115 Tarsal border, exploration of, 16, 28-33 Tarsal ophthalmia, 2070-2103 Tarsoraphia, 2166 Terminations of inflammation, 223-260 Tinea ciliaris, 2081-2103 Trachoma, 983-990 Traumatic ophthalmiae, 970-982 Tremulous iris, 1087 Trichiasis, 2198-2225 Trichosis bulbi, 2336-2338 Tube for nasal duct, 2513-2519 Tumour, albuminous, in eyelids, 2287-2296 encysted, in eyelids, 2280-2286, 2297-2298 connected with the iris and aqueous chambers, 1164 in neighbourhood of lachrymal gland, 2383 fibrinous, in eyelids, 2289-2291 spongoid or medullary of eyeball, 1166-1190 Tumours, conjunctival, 2336-2338, 2343-2345 in eyebrow and eyelids, 2271-2299 brain, producing amaurosis, 1841 orbit, 1828, 1838, 2545 \ non-malignant, in vitreous humour, 1159 of choroid, 1159 cornea and sclerotica, 1159 eyeball, 1159-1164 iris, 1164 within eyeball, 1159-1164 Turpentine, its use in corneitis, iritis, &c, 430, 686, 777, 810, 827 Twitching of eyelids, 19 Tylosis, 2086 Ulceration, 260 Ulcers of cornea, 348, 350, 997-1000 eyelids, cancerous, 2308-2318 scrofulous, 2084 syphilitic, 2114 Uvea, staphyloma of, 1071-1075 Uveitis, 380, 389 INDEX. 509 Vaccination, cure of naevus maternus by, 2302 Vapours, of aromatic or narcotic substances to the eyes, 116 medicated, to the eyes, 115 stimulating, 118 watery, 114 Varicositas oculi, 1076-1086 Variolous ophthalmia, 944-957, 2061-2062 Vascular cornea, 1012-1015 speck, 701,713 Venery, a cause of amaurosis, 1862 • Vessels, state of in inflammation, 179-183 Vision, coloured, 1687-1688 defective, various states of, 4, 1605-1705, 1735-1898, 1901-2036 Visus defiguratus, or metamorphopsy, 1951 dimidiatus, 1787 increscens, 1789 interruptus, 1787 Vitreo-capsulitis, 295 Vitreous body, dissolution of, 1087-1088 dropsy of, 1135-1140 non-malignant tumours in, 1159 Warm applications to the eyes, 113-116 Warm cataplasms and fomentations, 113 Warmth, dry, 116, 117 Warts on eyelids, 2276-2277 of conjunctiva, 2343 Watery eye, 46, 2373-2375 vapours to the eyes, 114 Weakness of sight, 1691-1705 Web, 2322-2333 Wenzel's operation for artificial pupil, 1550 Wollaston on semi-decussation of optic nerves, 1766 Woolhouse's operation for closed pupil, Introduction Worms, amaurosis from, 1854 Wound, healing of a, 246-256 Wounds, gunshot, of eye, 2599 of choroid, 2650 cornea, penetrating, 2604-2606 punctured, 2609-2619 eyebrows and eyelids, 2656-2674 sclerotica, 2651 penetrating orbit, 2684-2688 Xeroma, conjunctival, 991-995 lachrymal, 2369-2372 Xerophthalmia, conjunctival, 991-995 lachrymal, 2369-2372 Zonula, cataracta cum, 1273 THE END. 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