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With the'compliments of the Author. 
IRIDOTOMY, 
AND ITS 
APPLICABILITY TO CERTAIN DEFECTS 
OF THE EYE. 
BY A. W. CALHOUN, M. D., 
Professor of Diseases of the Eye and Ear in the Atlanta Medical College. 
REPRINT FROM THE SOUTHERN MEDICAL RECORD. 
ATLANTA, GEORGIA: 
SOUTHERN PUBLISHING CO., STEAM PRINTERS, BOOK BINDERS, ETC. 
1875. IRIDOTOMY, 
AND ITS APPLICABILITY AS A REMEDY 
FOR CERTAIN DEFECTS OF THE EYE. 
WITH FOUR ILLUSTRATIVE CASES. 
IB IT A.. W. H/L.JD., 
Professor of Diseases of the Eye and Ear in the Atlanta Medical College. 
The operation bearing the above name has long been known, and 
even to some extent, though in a rude way, put into practice; but 
to DeWecker, of Paris, belongs principally the honor of having 
perfected and brought prominently before the profession the opera- 
tion as it now exists, and of having so applied it, that it recom- 
mends itself under certain circumstances as a substitute for the old 
operation of iridectomy. 
An iridectomy is the Gutting out a greater or less portion of th#» 
iris; an iridotomy is the Gutting into the iris, but removing no por- 
tion, yet without the loss of any of the tissue, accomplishing the 
same purpose, viz.: the entrance of light into the interior of the 
eye through an artificial pupil. It needs no argument to demon- 
strate that of two modes of operating, that is best which attains 
the same good end with the least sacrifice of the parts operated 
upon. If incising a diseased finger answered the same and perhaps 
a better purpose than the excision of the member, but few moments 
would be consumed in deciding upon the proper mode of procedure. 2 
Iridotomy. 
If ah incision into the iris does a service equal to an excision of a 
portion of it, there should be no hesitation in resorting to the first? 
even though it should possibly require the more skill and care of 
the two. Ocular defects demanding the formation of an artificial 
pupil have heretofore been always met by an iridectomy, but the 
recent advances in ophthalmic surgery teach that this was in many 
instances a useless expenditure of tissue, and that an iridotomy 
would have done the same, whereby many inconveniences and dis- 
advantages attending the first could have been easily avoided. 
In making an iridectomy, it is often desirous to have the open- 
ing in the iris as small as possible, for when the operation is made 
with the view simply of letting the rays of light pass through into 
the interior of the eye, a large iridectomy, to a great extent, defeats 
the very object it is desired to accomplish, by permitting the pass- 
age of too much light, and thereby producing, so to speak, a con- 
fusion of vision. An iridotomy meets this objection thoroughly, 
as simply a slit is made into the iris, and only so great an open- 
ing is produced as is brought about by the contractility of the 
parts, separating the cut edges of the iris, usually to a slight but 
sufficient degree. 
The four cases I have recently operated upon, and which I now 
report, demonstrate fully the advantages of the more recent opera- 
tion (the iridotomy) over that usually made (the iridectomy) for the 
same troubles. 
Case I.—C. C., of Florida, set. 58, and in good health, was 
operated upon in November, 1874, by Graefe’s Linear Extraction, 
for the removal of cataract from the left eye. From some cause 
previous to the operation, the lens had become partially dislocated, 
and immediately upon finishing the incision through the upper 
eorneo-sclerotic junction, and upon the outflowing of the aqueous 
humour, the displaced lens presented itself at the edge of the wound 
and was at once removed, even before the iridectomy, which is a 
part of this operation, could be made. 
Instead of the iris prolapsing after the exit of the lens, it 
turned backwards into the vitreous humour towards the ciliary 
bodies. As the vitreous was soft and threatened to escape in a 
dangerous quantity, it was thought best not to trouble the iris with 
the view of cutting out a portion of it, particularly since it was Iridotomy. 
well out of the wound, and left the pupil in tolerable shape and 
position. The wound healed nicely, and by the use of atropine, 
the iris with the pupil, was brought back inti) proper place. Sev- 
eral days later, by an unlucky movement and a violent strain on 
the part of the patient, the corneo-sclerotio wound was ruptured, 
and a probpsus of all that part of the iris took [dace, correspond- 
ing to the inner edge of the wound. Severe'inflammation followed, 
and upon recovery it was found that the large prolapsus was ad- 
herent to the edges of the wound, and the pupil drawn so high up 
towards the upper corneal border and underneath the upper lid, 
that the patient could only make out objects at any distance very 
indistinctly. Chloroform was given, the lids held apart by an 
assistant and the prolapsed iris clipped away close up to the cornea, 
and an iridotomy made in the following manner: 
Through the opening made by cutting away the prolapsus, the 
closed blades of DeWeoker’s scissors were passed into the anterior 
chamber as far as the lower pupillary border; here the blades were 
allowed to separate, and one passed through the pupil and behind 
the iris, the other in front of the iris, and the instrument pushed 
gently downwards towards the bottom of the anterior chamber,, 
until the larger portion of the iris, between its pupillary margin 
and its periphery, was caught between the blades, which upon 
being brought firmly together, made a straight incision through the 
substance of the iris, severing the circular muscular fibres (the 
sphincter), the divided ends of which contracting, drew the two cut 
surfaces away from each other, leaving a triangular opening with 
the base upwards toward the pupil, and the apex downwards to- 
ward the periphery of the iris or bottom of the anterior chamber. 
Under the ordinary treatment, the eorneo-sclerotic wound healed 
rapidly, the iridotomy permitting the free entrance of light into the 
eye. Upon being dismissed a little later, his vision was f with 
No. 4 double convex (or cataract) glass, and with No. 24 cataract 
glass he read small type. 
Case II.—Wm B., of Georgia, set. 25. This patient has had 
gran ophthalmia in both eyes, producing a deep ulcer upon the 
centre of the left cornea. By persistent treatment with nitrate 
silver, sulph. copper, etc., the granulations have disappeared, and 
the corneal ulcer in the left eye has healed; but there exists in its 4 
Iridotomy. 
stead a thick opacity, situated directly in front of the pupil, and in- 
terfering materially with good vision. Dilating the pupil and ex- 
amining the fundus of the eye with the ophthalmoscope through the 
clear portion of cornea, everything within was found to be perfectly 
normal, and with the pupil in this dilated condition, the vision 
(particularly for distant objects) was immensely improved, the rays 
of light passing without hindrance through the transparent parts of 
the cornea. ’Twas evident that an artificial pupil would greatly 
increase the vision, and with this in view, the iridotomy was decided 
upon as soon as the pupil had contracted to its original size, early 
in December, 1874. The operation in this case required still 
greater care and caution than the other, on account of the presence 
of the sound lens, which, as will be remembered, had become cata- 
ractous, and been extracted in the first case, before the necessity for 
the iridotomy arose. With the lids held apart and the eye securely 
fixed, an opening was made through the upper corneo-sclerotic 
junction, by means of a spear-shaped iridectomy knife, and through 
this opening the closed blades of De Wecker’s scissors were ad- 
vanced into the anterior chamber till the lower margin of the pupil 
was reached. Opening the blades, one was passed through the pu- 
pil behind the iris and resting upon the anterior capsule of the lens, 
the other in front of the iris, and the instrument forwarded until 
there rested between the blades a sufficient amount of iris, which 
was divided, and at once a free triangular opening was made by the 
contractility of the parts separating the cut edges. 
When seen on the following day, and after the anterior chamber 
had refilled, the cut edges of the iris had drawn still farther apart, and 
a sufficiently large artificial pupil was formed below the corneal 
opacity to permit of excellent sight. There was no accurate test 
of vision made, yet the patient, as well as myself, was daily con- 
vinced of its great improvement. I have recently heard from him, 
and to the effect that his vision has been steadily improving. 
Case III.—J. L. G., ofN. C., set. 27. In February 1875, an 
iridotomy was made upon this patient for relief from exactly the 
same trouble as in the last. He had had gran ophthalmia for sev- 
eral years, and upon the left cornea an ulcer had formed. After 
curing the granulations and the ulcer, there remained behind, a 
central corneal opacity, which, as is often the case, had rendered Iridotomy. 
5 
him myopic (near sighted), and even for near objects vision was in- 
distinct, and there was an “overstrained” feeling about the eye, 
whenever he attempted to fix his vision upon anything. The ut- 
most extent of his vision was -f-, and this was rather uncertain. 
The lens being also present here, the same precautions were nec- 
essary, and precisely the same steps were gone through with in 
making the operation, as in the previous case. No undue inflam- 
mation followed the operation, and upon a re-accumulation of the 
aqueous humour, a large opening existed in the iris below the opac- 
ity. The patient was dismissed the latter part of March with vision 
amounting to f, perfectly clear and distinct. But more particularly 
for distance was the improvement most marked, small objects be- 
ing readily recognized now, which before the operation were not 
seen at all, or only their outlines made out. The “ overstrained ” 
feeling (as the patient described it) was totally removed, no doubt 
by the free, unobstructed entrance of light into the eye. 
Corneal opacities not unfrequently are the causes of a greater or 
less degree of myopia, and this case is particularly interesting, on 
account of this defect of refraction being to a great extent relieved 
by the operation. 
Case IV.—Miss C. of Ga., set. 35. In this lady mature cata- 
ract had made its appearance at an unusually early age. The 
lens was removed from the right eye by means ofGraefe’s linear ex- 
traction, in which a large upward iridectomy was made. On the 
3d or 4th day after the operation, a slow subacute iritis set in, last- 
ing for several weeks and resulting in the complete occlusion of the 
natural and artificial pupils by the formation of a thick exudative 
membrane, producing what is ordinarily known as secondary cat- 
aract, and the drawing of the pupil high up underneath the upper 
lid. Vision, which was good immediately after the operation, was 
now gone. 
Several months after the extraction, the iridotomy was performed. 
An opening was made through the upper part of the cornea, with 
the spear-shape knife, the point of which, on entering the anterior 
chamber, was also made to puncture the membrane filling the pupil. 
One blade of the iridotomy scissors was passed through the punc- 
ture behind the membrane, the other in front, and pressed down- 
ward till the whole width of the membrane and a large part of the 6 
Iridotomy 
iris were brought between the two blades, which being closed, di- 
vided both the obstructing membrane and the iris. As the two 
sides of the iris drew away from each other, they carried with 
them the corresponding sides of the divided membrane, forming a 
large artificial pupil through which the lightcould pass unobstructed. 
The patient could immediately count fingers without hesitation, 
distinguishing between the different ones with accuracy. 
While waiting for the eye to recover thoroughly from the effects 
of the operation, before making a scientific test of the vision by 
means of the test types, she was called suddenly home, and the op- 
portunity for getting very exactly the degree of vision, was lost; 
still it is sufficient to say that before leaving, with No. 4 cataract 
glass, she had been walking about without assistance, seeing as 
well as one usually does at this time, after the successful removal 
of cataract. With No. 2J cataract glass she was able to read print, 
a size larger than the ordinary print of newspapers. 
After a completely successful extraction of cataract, the vision is 
constantly improving for several months. Upon the iridotomy 
proving successful in this instance, it was simply successfully com- 
pleting the cataract operation, and I have no doubt, indeed have 
been informed, of the gradual increase in vision for several months 
after the operation. 
In each of the foregoing cases it will be seen, that where the op- 
eration (the iridectomy) usual for the relief of such troubles was 
indicated, the iridotoviy was made instead, and with gratifying suc- 
cess in every instance. 
To repeat then, this operation recommends itself from the fact 
that no part of the iris tissue is destroyed or taken away, and that 
the artificial pupil thus made, is sufficiently small to prevent the 
letting* in of too much light. This latter is, in particular, a great 
point gained. There is usually no difficulty in making a large 
pupil, but on the contrary, to get it small enough to concentrate 
the rays of light, in some degree, and thereby overcome the con- 
fusion produced by the rays scattering after passing through a 
large opening, is oftentimes by no means an easy matter. 
It issomewhatdifficult to perform it, in thoseeases wherethe lensjis 
present, for one blade of the instrument (the scissors) must necessarily 
rest upon the anterior capsule of thelens, findingits way slowly down Iridotomy. 
between this and the posterior surface of the iris, for when the 
corneal or corneo-sclerotic opening is made, the aqueous humor 
rushes out, and the lens and the iris on its posterior surface, 
forced together. The danger is in wounding the lens or its capsule 
and producing traumatic cataract, but with the requisite care and 
skill, there should be but little fear of this taking place. Where 
the lens has already been removed, we have no such trouble to 
contend with, and the operation is much more easily performed.— 
One other precaution is specially necessary, viz. : to replace the 
prolapsed portion of iris which juts out of the external wound as 
the aqueous humor flows out. This is readily replaced by using 
a blunt pointed stylet. 
In cases of lamellar cataract, where the margin of the cortical 
substance is perfectly clear (which can be more distinctly seen when 
the pupil is widely dilated), the iridotomy would answer an admi- 
rable purpose. The lens is not sufficiency opaque to be extracted, 
or to cause its absorption by means of discission or laceration; but 
the only thing necessary to give clear vision is to make a small cut 
(a slit) through the iris so as to allow the light to impinge upon 
the transparent portion of the lens. The iridotomy would do this 
perfectly, and avoid the confusion of sight which would most prob- 
ably be produced, should a part of the iris be clipped off. 
Central capsular cataract is occasionally so large as to almost en- 
tirely fill the pupil when of normal size. It is necessary to do 
something in order to allow the child the proper exercise of the 
eye. Here, also, the iridotomy would certainly be preferred to the 
usual modes of operating. 
The operation is particularly serviceable in those cases where 
iritis or irido-cyclitis has followed cataract operations by extraction, 
and as a consequence, a more or less thick membrane (secondary 
cataract) has filled up the natural pupil and the iridectomy. These 
membranes are often so tough and firm that it is_dapgerous to exer- 
cise sufficient power with the? needle to break -ft- up, or even to 
make a single rent through All who have had such cases to 
treat, can well recall to mind how often they have been compelled 
to make operation after operation, before setting aside the obstacle. 
The iridotomy leaves a single cut through both the membrane 
and the iris, (the pupil being drawn upwards by the contraction of 8 
Iridotomy. 
its tissue and the membrane), and the sphincter muscle acting, sep- 
arates the cut edges of the two, one from the other, and forms an 
opening of greater or less size. This avoids a second iridectomy, 
which is frequently made under such circumstances. 
Diseases of the lids as well as of the cornea, not unfreqently re- 
sult in permanent opacities upon the cornea, which obstruct the 
vision more or less, according to their situation, covering the pupil 
in part or entirely. In many of these cases, it is only necessary to 
change the position of the pupil to a point behind a transparent 
portion of the cornea, to dispel the cloud which may have so long 
shut out the bright light from the diseased eye, and permit of clear, 
almost perfect vision. For the accomplishment of this, the iridec- 
tomy has hitherto been almost the sole remedy, notwithstanding 
that results often followed it which were extremely disturbing in their 
nature. The iridotomy affords the same good, and but few if any 
of the subsequent confusing results take place, but it requires 
greater caution and possibly more skill than the iridectomy. 
There are cases, of course, where the latter operation cannot be 
dispensed with, but the iridotomy is by far preferable whenever a 
small artificial pupil is desired, or in those cases where to re- 
move a portion of the iris would originate inconveniences almost 
if not quite counterbalancing the advantages.