RESUME OF THE MODERN VIEWS 
OF THE 
Pathology and Treatment of Glaucoma 
By C. S. FENNER, M. D. 
LOUISVILLE, KY. 
READ BEFORE THE KENTUCKY STATE MEDICAL SOCIETY, 1874. 
LOUISVILLE: 
PRINTED BY JOHN P. MORTON AND COMPANY. 
1874. RESUME OF THE MODERN VIEWS 
OF THE 
Pathology and Treatment of Glaucoma 
By C. S. FENNER, M. D. 
LOUISVILLE, KY. 
READ BEFORE THE KENTUCKY STATE MEDICAL SOCIETY, 1874. 
LOUISVILLE: 
PRINTED BY JOHN P. MORTON AND COMPANY. 
1874. PATHOLOGY AND TREATMENT OF GLAUCOMA. 
Previous to the invention of the ophthalmoscope but little was 
known of the pathology of glaucoma. From the greenish reflex of 
the fundus of the eye it derived the name of glaucoma or green 
cataract. Authors took much pains to point out the distinguishing 
symptoms between the incipiency of this disease and the first stages 
of cataract and amaurosis. Mackenzie says, “To distinguish glaucoma 
from cataract, especially in the incipient stage, proves to beginners 
one of the most difficult pieces of diagnosis, and sometimes not to 
beginners only, but to those who for a length of time have attended 
to the diseases of the eye. . . . Glaucoma is often mistaken for 
amaurosis, from the circumstance of being always attended by some 
of the subjective symptoms of this disease." 
When it was sufficiently developed to make the diagnosis clear and 
unmistakable the patient had to be assured that he would sooner or 
later become totally blind, and no hope would then remain for the 
restoration of his vision. Now what a change! By the aid of the 
ophthalmoscope the first stages of the disease can be diagnosticated 
with almost unerring certainty; the pathological changes watched as 
they progress; and, thanks to the genius of Von Graefe, we are enabled 
to assure the suffering patient that his sight can with great probability 
be entirely preserved, or at the worst will be but slightly impaired. 
Thousands are now in the enjoyment of good vision who had they 
lived a quarter of a century ago would have been hopelessly blind. 
Mackenzie first pointed out the fact that an increased hardness 
of the eye always existed in glaucoma; but he failed to discover the 
causes of the increased intra-ocular tension, and of its effects on the 
interior structure of the eye. Even after the monocular ophthalmo- 
scope came into general use it was some time before surgeons learned 4 
PATHOLOGY AND TREATMENT OF GLAUCOMA. 
to correctly interpret all the phenomena the interior of the eye pre- 
sented. In the examination made with but one eye of the observer 
the effect of stereoscopic vision with both eyes was wanting; depres- 
sions seemed as elevations, and the glaucomatous cupping of the optic 
disk appeared and was described as an arching forward of the nerve- 
entrance. 
Yon Graefe first detected this error, and showed that what appeared 
as an elevation was an optical illusion; that the disk was actually 
pressed backward, forming an excavation. From this change in the 
form of the optic papilla, taken in connection with the increase of the 
intra-ocular tension, he saw at once that new light was thrown on this 
hitherto obscure disease. He argued that the cupping of the optic 
disk was the result of the increased intra-capsular tension. It is 
precisely the same as if we were to take a hollow ball of some slightly 
elastic substance and force into it a fluid. The more thrown in the 
harder the ball becomes. Now if a small portion of its walls is 
weaker than at other parts, this weaker or thinner portion, offering 
less resistance to the internal pressure, would give way and be forced 
outward. This is just what takes place in glaucoma. There is an in- 
crease of the fluid contents of the capsule; that part of the sclerotica 
corresponding to the entrance of the optic nerve and blood-vessels 
(lamina cribrosa) is perforated to allow the vessels and nerve-fibers to 
pass into the eye; around these perforations the sclerotica is thicker 
and stronger than at any other place, because here it receives the 
addition of the outer sheath of the optic nerve; hence the edge of 
the scleral foramen is sharp, very firm, and unyielding. The fibers 
of the scleral tissue passing between the nerves and blood-vessels, 
offering less resistance to the increased intra-ocular pressure, being 
the wreaker part, gives way and is pressed backward. As they pass 
behind the thickened ring surrounding the lamina cribrosa they 
not only expand backward, but laterally, forming a flask-shaped sack, 
having an opening corresponding to the resisting edges of the scleral 
perforation. The nerve-fibers and blood-vessels are put upon a stretch 
and bent over this sharp edge. If an elastic tube conveying fluid is 
bent over the sharp edge of a hard substance, the walls of the tube 
are compressed at that point, and the passage of fluid in them is more 
or less impeded. Now this is just what takes place in the blood-vessels 
accompanying the optic nerve. They are bent and stretched over the PATHOLOGY AND TREATMENT OF GLAUCOMA. 
5 
resisting edge of the scleral foramen ; the walls of the arteries, being 
firmer and more resisting than the walls of the veins, still continue to 
convey the blood, but in less quantities than normal;' the veins being 
thinner and more compressible, the circulation in them is impeded 
to a greater degree; hence they become engorged and swollen. The 
obstruction and lateral pressure exerted on the arteries prevents their 
gradual yielding to the impulse of the blood, and they only receive 
the blood after the impulse has become very strong; hence the arterial 
pulsation is seen spontaneous and jerking. The capsule being dis- 
tended by the intra-ocular pressure of the fluids of the eye until 
it has lost its elasticity, each arterial pulsation adds to the incom- 
pressible fluid contents of the globe. The result is that each arterial 
pulsation increases suddenly the lateral pressure on the veins, and 
forces by quick compression venous blood through the obstruction 
at the edge of the optic papilla, while they immediately refill, to go 
through the same process after each pulsation of the arteries. Thus 
we have spontaneous arterial pulsation and venous pulsation, which is 
pathognomonic of increased tension of the eye in glaucoma. By pres- 
sure on the normal eye spontaneous arterial pulsation and pulsation 
in the veins can easily be produced. Bearing these points in mind, 
most of the phenomena connected with glaucoma are easily explained, 
and are just what a priori would be expected : certain results follow 
certain causes. We should look for just such pathological changes 
from increased intra-ocular tension or great rigidity of the sclerotica; 
and if means could be found to restore the eye to its normal tension, 
the loss of vision would be prevented or restored if organic lesions 
beyond reparation had not already taken place. 
This is what Graefe accomplished. He found means to relieve 
this increased intra-ocular tension and restore the eye to its normal 
hardness, and thus to check those pathological changes that surely 
tend to organic lesions, causing total loss of vision. If he had done 
nothing else tending to the advancement of ophthalmological science, 
his name would be imperishable. He found by experiment that an 
iridectomy, removing a large section of the iris up to its peripheral 
attachment, relieved the increased intra-ocular tension, and re-estab- 
lished the normal endosmotic equilibrium between the circulation in 
the blood-vessels and the fluid contents of the eye. 
When he first published his views on this subject to the world in 6 
PATHOLOGY AND TREATMENT OF GLAUCOMA. 
1856 his conclusions were received with a good deal of incredulity, 
because this happy result of the operation could not be explained on 
rational principles. Many surgeons repeated the operation without 
deriving the expected benefit. I remember seeing a case of glaucoma 
in the clinique of Desmarres, in i860, in which he had a short time 
previously removed a portion of the iris. The vision of the patient 
was not improved. It was a case of confirmed glaucoma, where, 
according to our present knowledge, no benefit could be expected 
beyond relief from pain, because organic changes had taken place 
beyond the power of reparation. As surgeons became more familiar 
with the use of the ophthalmoscope, and learned more correctly to 
diagnosticate the earlier symptoms of glaucoma, and to appreciate the 
effects of increased tension of the eye, they were led to perform the 
operation of iridectomy at an earlier period, according to the in- 
structions of Von Graefe, with results so favorable that it is now an 
almost universally established operation for the relief of increased 
intra-ocular tension. 
Symptoms of Glaucoma.—“These comprehend the senile increase 
of the hardness of the globe, the ophthalmoscopic appearances of 
excavations of the optic nerve, the symptoms of hyperaemia and 
inflammation, as well as a great variety of disturbances of vision.”— 
{Stellwag.) 
An abnormal hardness of the eye is one of the first objective 
symptoms, and this increased tension varying from a slight degree, 
as evidenced by the touch, to the hardness of bone or ivory. A rapid 
diminution of the refractive power of the eye is usually noticed (pres- 
byopia), which the patient is at first disposed to regard as the result 
of senile changes, and he seeks relief in convex glasses. These have 
frequently to be changed for those of higher power, until he finds that 
he requires their use in order distinctly to see remote objects {hyper- 
metropia'). This diminution in the refractive power of the eye is 
probably owing to the intra-ocular pressure, which has a tendency to 
cause the cornea to assume a spherical shape corresponding to the 
curvature of the sclerotica. In the latter stages of glaucoma the ridge 
around the sclero-corneal junction disappears. The increase of intra- 
ocular pressure may be rapid, or it may be very slow and only noticed 
at certain times, as after a full meal, excesses in drinking, loss of sleep, 
etc. The premonitory attacks are most usually periodical, and may PATHOLOGY AND TREATMENT OF GLAUCOMA. 
7 
be attended by intense headache and ciliary neuralgia, with evidence 
of acute inflammation; or the disease may steadily progress to total 
loss of vision without pain or perceptible inflammatory symptoms. 
The increased tension is evidently due to an excess of fluid secretion 
in the vitreous. As the eye grows more and more hard the pupil 
becomes widely dilated, the iris motionless, and forms a narrow ring 
around the margin of the cornea; it together with the crystalline 
lens is pushed forward till they rest against the posterior surface of the 
cornea, and thus entirely obliterate the anterior chamber. The secre- 
tion of the aqueous humor ceases from atrophy of the uveal portion 
of the anterior chamber. The cornea becomes anaesthetic, varying in 
degree according to the amount of intra-ocular tension: this insensi- 
bility may be evenly distributed over its entire surface or confined to 
certain portions of it. When the internal pressure becomes very great 
and continues for a length of time, the cornea becomes so insensible 
that its surface may be rubbed with the finger or brushed with a feather 
without causing any pain or reflex action. This insensibility is un- 
doubtedly due to a pressure on or a stretching of the nerve-fibers 
supplying this part of the globe. Irritating substances lodge upon the 
surface of the cornea, and as they produce no pain or reflex action 
are not rubbed off by nictation or washed away by the tears; hence 
they remain there, giving rise to inflammation, ulceration, opacities, 
etc.—results similar to those following paralysis or injuries of some 
of the branches of the fifth pair of nerves. Greatly enlarged veins 
finally are seen bursting out from the anterior portions of the sclerotica, 
which anastomose and pass tortuously over the equator of the globe, 
while near the sclero-corneal junction there is a fine vascular net-work 
of vessels, more particularly evident during an attack of intense inflam- 
mation. Finally the sclerotica becomes thin, translucent, and of a 
whitish porcelain appearance. As the hardness of the eye increases 
the disturbances of sight become more and more manifest. The field 
of vision is gradually obscured. In daylight a thick fog prevents 
distinct perception of objects; by artificial light, as in looking at a 
lighted candle in a dark place, a halo is seen around the flame that 
gives all of the colors of the rainbow, the inner side being red, the 
outer green. Soon objects cease to be perceived on the inner part 
of the visual field; this insensibility gradually extends eccentrically 
above and below until the ends meet on the outer side, leaving a 8 
PATHOLOGY AND TREATMENT OF GLAUCOMA. 
narrow slit of sensitive retina extending downward and outward. 
This gradually closes, until finally all quantitative perception of light 
is gone. The patient long after this has periodically subjective sensa- 
tions of light; hence he has his light and dark days. 
Ophthalmoscopic Appearances.—When the increased hardness of the 
eye becomes plainly manifest the optic disk is found slightly excavated 
or pushed backward; the arteries are of normal size or slightly dimin- 
ished in caliber; the veins are swollen and a little flattened. As the 
intra-ocular pressure increases the disk becomes more and more cupped, 
the arteries diminish in size, while the veins are larger and more tortu- 
ous. The blood-vessels passing over the edge of the disk are seen bent 
or arched backward; venous pulsation becomes visible, or may be pro- 
duced by slight pressure with the finger, followed by spontaneous arte- 
rial pulsation. When the tension of the eye becomes very great the 
excavation of the disk is deep and flask-shaped; all its blood-vessels 
disappear; its color, which at first, owing to venous congestion, was 
of a reddish hue, now becomes of a grayish-blue or a tendonous-white. 
The retinal vessels are sharply cut off at the edge of the disk, where 
they appear beak-shaped, particularly those which pass in an oblique 
direction. The veins are greatly enlarged, and the collateral branches 
assume a corkscrew appearance, while the arteries are more or less 
atrophied. Retinal ecchymosis is often seen. In the advanced stages 
of glaucoma a characteristic yellowish-white ring surrounds the optic- 
nerve entrance, which increases in breadth as the excavation grows 
deeper. 
The above-enumerated symptoms and pathological changes consti- 
tute glaucoma, which may or may not be accompanied by inflammation; 
hence the disease is usually described under the heads of inflammatory 
and non-inflammatory glaucoma. 
Inflammatory Glaucoma. — This form of the disease is generally 
attended by a premonitory stage, each attack being followed by a 
perfect intermission, which may last for weeks or months; the attacks 
grow more and more frequent, until after a time there ceases to be a 
perfect intermission, but only a remission of the more acute symptoms. 
The glaucoma is now said to be confirmed. During the permonitory 
stages the patient when looking at a lighted candle sees around the 
flame the prismatic halo. This appearance may be at first the result 
of simple pressure on the nerve-fibers, but after a time it is generally PATHOLOGY AND TREATMENT OF GLAUCOMA. 
9 
accompanied by a cloudiness of the aqueous and vitreous humors; 
hence the prismatic halo and haziness is probably due to diffraction. 
This haziness is at first transitory, sometimes appearing several times 
during the day, and lasting but a few minutes. When the inflamma- 
tory symptoms become more severe the blueish-gray haziness is so 
great and the fundus of the eye is so completely obscured that an 
ophthalmoscopic examination can not be made. The premonitory 
attacks are generally preceded or accompanied by severe headache, 
with ciliary neuralgia. If the inflammation is of very high degree, 
these pains are often agonizing, and vision may be totally lost in the 
course of a few hours (,glaucoma fulminans); but generally this result 
does not take place until after repeated exacerbations, each one 
of which adds to the impairment of vision, until at the end all quan- 
titative perception of light disappears. The haziness that obscures the 
field of vision during the premonitory stages often disappears after 
sleep. In persons advanced in life the eye gives from its fundus a 
greenish reflex; but this is not seen before middle age. Senile 
changes in the lens give its nucleus a yellowish-amber color. In 
glaucoma the bluish-white opacity of the vitreous mingling its color 
with the amber-colored lens gives a greenish reflex. The green color 
disappears if the lens is removed, showing that it is only a combina- 
tion color. 
Chro?iic Inflammatory Glaucoma.—This form of the disease is also 
accompanied by a premonitory stage, but usually there is a remission 
of the more prominent symptoms, rather than perfect intermission. 
The intra-ocular tension slowly increases; but the pain is less severe 
than in the acute form, or it may be entirely absent. The progress 
of the disease is slow; but the final result is the same—total loss 
of- vision. Frequently before this takes place there are one or more 
attacks of acute exacerbation. These exacerbations may continue long 
after vision is totally destroyed, giving rise to intense pains in the 
head, with severe ciliary neuralgia; the inflammation may extend to 
the conjunctiva, causing chemosis and great swelling of the lids. 
Noninflammatory Glaucoma (Glaucoma Simplex).—This form of 
the disease is insidious in its approach, and often makes considerable 
advances before the patient is aware of it. If confined to one eye, he 
often accidentally finds that he can not see as well with it as with 
a sound one. Small objects are indistinctly seen, and the limitation 10 
PATHOLOGY AND TREATMENT OF GLAUCOMA. 
of accommodation progresses to hypermetropia. This limitation 
of accommodation can at first be remedied by convex glasses. There 
is no prismatic halo around a lighted candle; but after a while vision 
becomes misty, and objects are indistinctly perceived. The eye has a 
normal appearance, but the iris is a little sluggish in its movements. 
To the touch, the globe will be found to be a little harder than natural, 
and the ophthalmoscope reveals a slight displacement of the porus 
opticus backward, with perhaps a bending of the retinal vessels in the 
optic papilla, and by slight pressure venous pulsation and spontaneous 
arterial pulsation can be produced. 
The disease may remain almost stationary for months or years, but 
eventually the intra-ocular tension slowly increases, the iris dilates to 
a narrow ring, the aqueous chamber diminishes in size, the eccentric 
contraction of the field of vision from the inner side gradually ex- 
tends, the cornea becomes anaesthetic, the optic disk deeply cupped, 
and the eye approaches the hardness of bone. All of the pathological 
changes enumerated as resulting from increased intra-ocular tension 
take place, until finally all perception of light is gone, often without 
the patient having suffered pain or the appearance of inflammatory 
symptoms. There is an absence of retinal ecchymosis in such cases; 
but more frequently before vision is totally destroyed exacerbations 
of acute inflammation come on and hasten the final result. 
Secondary Glaucoma is where the increase of intra-ocular tension 
supervenes or results from some other affection of the eye, as large, 
deep cicatrices of the cornea, serous choroidetis, anterior or posterior 
synechia or irido-cyclitis. The latter is often induced by wounds of 
the anterior capsule, whereby the aqueous humor is admitted to the 
lens, causing the latter to swell from the absorption of the fluid, and 
thus to press on the iris and ciliary body. This is why it is so dan- 
gerous to freely open the anterior capsule in the operation of discission 
for cataract in persons advanced in life. The irritation induced by 
a hard lens displaced in the vitreous humor, causing irido-cyclitis, 
terminating in glaucoma, is the chief reason why so many eyes have 
been lost a few months after the performance of the now-abandoned 
operation of couching. 
Treatment.—In the premonitory stage of glaucoma, when a con- 
siderable time intervenes between the attacks, great care should be 
exercised to avoid every thing that has a tendency to induce hyper- PATHOLOGY AND TREATMENT OF GLAUCOMA. 
11 
aemia of the retina or choroid. The diet should be nutritious, but the 
stomach not overloaded with indigestible food. Hearty suppers and 
all excesses in drinking spirituous liquors should be avoided. The habits 
should be regular, particularly as to the hour of retiring, so as to avoid 
loss of sleep. Care should be taken not to use the eyes too long in 
continued reading fine print, writing, etc., and particularly to avoid 
reading in a recumbent position. If there is a diminution in the 
powers of accommodation, convex glasses should he worn of sufficient 
power to make objects distinctly seen without straining the eyes. 
The chief object of treatment is to restore the eye to its normal ten- 
sion. This was formerly attempted to be accomplished by evacuating 
a portion of the vitreous, but without producing the desired result. 
Next the frequent tapping of the anterior chamber was tried. But the 
benefits derived from these operations were only temporary, few cases 
of glaucoma having been permanently relieved by this course of treat- 
ment. The only effectual remedy is an iridectomy carefully performed 
according to the instructions given by Von Graefe. It is best to remove 
the portion of excised iris upward, for then the upper lid covers the 
coloboma, and prevents circles of diffusion that would result from 
a removal of other parts of the iris. The incision should be made 
in the sclerotica at least half a line from the corneal junction. 
While an excision of a portion of the sphincter of the iris, as in the 
operation for artificial pupil, may in many cases give relief; yet to 
obtain the full benefits of the iridectomy at least one fifth of the iris 
should be removed and torn completely from its peripheral attachment. 
Great care should be taken that no portion of the iris remains in the 
angle of the wound. 
Graefe says, “Although it is certainly advisable to excise the iris as 
peripherally as possible, yet the non-fulfillment of these conditions is 
by no means always, not indeed usually, followed by insuccess. I have 
seen a very great number of eyes in which the operation had been 
imperfectly performed for typical inflammatory glaucoma, and yet in 
which the cure had been permanent. ... I would fain hope that 
these remarks will not induce carelessness in excising the iris.” He 
considers it of paramount importance “ that the iris should be care- 
fully and completely removed from the wound, for any inclusion of it 
in the cicatrix will certainly increase the secretory irritability of the eye. 
Had I to choose between a coloboma that does not reach quite to the 12 
PATHOLOGY AND TREATMENT OF GLAUCOMA. 
peripheral wound, but in which one edge of the coloboma is largely 
included in the cicatrix, I should always prefer the former 
In no case should the operation be concluded till we are certain that the 
iris is completely released from the wound i' 
In simple non-inflammatory glaucoma a little delay in performing 
the operation is a matter of no great importance; but in the acute 
form of the disease iridectomy should be performed as speedily as 
possible. If done within the first fourteen days of the attack, we 
may “restore and preserve to the eye nearly or entirely its full former 
functionary power.’ ’—(Stellwag.) 
In chronic inflammatory glaucoma it not infrequently happens that 
the patient is not seen by the surgeon until serious lesions have taken 
place. An iridectomy may arrest the progress of the disease, but often 
fails to completely restore the eye to its normal functions, because 
organic lesions have taken place beyond the power of reparation. 
Usually a few days after the operation the eye assumes very nearly 
or quite its normal hardness; the anterior chamber refills with aqueous 
humor; the cupped disk is flatter; and the pathological changes become 
stationary or diminish. , 
It sometimes happens that the iridectomy does not check the 
glaucomatous process. In such cases Graefe recommends a supple- 
mentary iridectomy, incising a diametrically opposite piece of the iris. 
He says, “I must indeed confess that I have become dubious whether 
incision of the adjacent piece has any influence over the tension. It 
is at all events very slight, and will generally not suffice in cases 
where the first iridectomy has had no sufficient or permanent effect. 
On the contrary, I could adduce at least a dozen cases where excision 
of the opposite piece has had a permanent effect after failure of the 
first iridectomy.” 
There is a singular result frequently following an iridectomy in 
acute inflammatory glaucoma. It is this: if the disease is confined 
to one eye, the operation, in a great majority of cases, hastens the 
appearance of the disease in the other eye; it generally comes on in 
from eight to fourteen days after an iridectomy on the glaucomatous 
eye. The patient should be apprised of this beforehand, and assured 
that a similar operation will with great probability soon be required 
on the other eye. 
It is always best to1 place the' patient thoroughly under the influence PATHOLOGY AND TREATMENT OF GLAUCOMA. 
13 
of chloroform previous to performing the iridectomy, as the evacuation 
of the aqueous humor suddenly relieves the eye of its great tension, and 
there is then a tendency in the degenerate walls pf the blood-vessels 
to give way and permit intra-ocular hemorrhage. The risk is greatly 
increased by the spasmodic contraction of the ocular muscles during 
the operation. These spasms are prevented in a great measure by 
rendering the patient insensible by means of an anaesthetic. 
It has not yet been satisfactorily explained how an iridectomy di- 
minishes the increased or abnormal intra-ocular tension of the eye. 
Wells says, “Amongst other hypotheses, some have thought that the 
tension was diminished by the excision of a considerable portion of 
the secreting surface; others that the removal of the iris quite up to 
its ciliary insertion, and the consequent exposure of the zonula zinnii, 
facilitates the interchange of fluid between the vitreous and aqueous 
humors, and thus diminishes the difference in the degree of tension 
between these humors. We must admit, however, that this problem 
has not at present been satisfactorily solved.” 
Graefe, in the last article he published on glaucoma, says, “No 
progress of importance has been made in respect to the theory of the 
operation, notwithstanding many attempts. Old hypotheses are usu- 
ally dragged forth, little as they avail for the explanation of existing 
facts. The unhappiest of all—the one referring the effect simply to the 
wound of the ocular capsule—is periodically brought forward, decked 
in some new formula, and recommended for adoption. Fortunately 
for our patients, practice advances independently on the foundation 
of empirical principles. No doubt some day a satisfactory theory will 
be found; but in the mean time we must not be led away by transient 
hypotheses.”