The Etiology and Early Management 
of Glaucoma. 
BY 
G. EDGAR DEAN, AT. D., 
Oculist to Lackawanna. Hospital, 
SCRANTON, PA. 
Reprint from The Ophthalmic Record, January, 1894. 
NASHVILLE, TENN.: 
A. II. Gray & Son, Book and Job Printers 
1894. THE ETIOLOGY AND EARLY MANAGEMENT 
OF GLAUCOMA* 
By G. EDGAR DEAN, M.D., 
Oculist to Lackawanna Hospital, 
Scranton, Pa. 
Although much attention has been given by authors to the 
subject of glaucoma, a great deal of the mysticism of the past 
has clung to it, causing most observers to class it with the 
inscrutable; while the few ventured to explain it by fine-spun 
theories. 
Believing that the theories of the causation of this important 
disease of the eye which I learned from the text-books of a 
dozen years ago or more and that which I heard taught in 
Vienna in 1887, must, from their very nature, be nothing better 
than fragmentary, I have been making some observations inde- 
pendent of theory, either dignified by age or newly preconceived. 
If the conclusions arrived at should-as I venture to hope- 
throw some light upon the etiology of the disease, give definite 
aim to the labors of the pathologist, and lead up to a more 
rational plan of prophylaxis or treatment than has prevailed in 
the past, I shall feel more than repaid for the effort expended 
in the researches. 
My first observation was that the theory given in the excel- 
lent treatise of Soelberg Wells-mostly quoted from Graefe, and 
which we may call the anterior inflammation theory-however 
attenuated, would not apply to all cases; and was therefore 
untenable as a general theory. 
* Read in the Section of Ophthalmology, Pan-American Congress, 
Washington, D. C., 1893. Early Management of Glaucoma. 
2 
My next observation was that the theory taught us in the 
clinic of the celebrated Prof. Stellwag, by his first assistant, and 
which we shall call the choroiditis theory, while approaching a 
little nearer the bottom facts, did not at all cover the ground, 
it being evident that while degenerative choroiditis might be 
present, in a good many cases it was as likely to be a part of 
the pathological process as to maintain the higher relationship 
of cause to effect. 
Then I observed year after year, that-with few exceptions- 
the cases of decided glaucoma, of threatened glaucoma and of 
glaucomatous cupping without active symptoms, were in persons 
affected with astigmatism (frequently conjoined with hyperme- 
tropia); and it seemed to matter little how small the degree, 
0.25 of a dioptre being a not infrequent showing. 
Later I began to observe that the exceptional cases were 
myopes in whom a more or less similar condition of back-pres- 
sure existed ; or what is relatively the same, posterior weakness 
of the eye-ball. 
My next investigations led me into a study of the so-called 
" physiological cupping," and I found it such an elusive subject 
that I at last concluded that it was to a very considerable extent 
a delusive one. Perhaps the fairest explanation of it in all 
respects that can be given in brief, is to compare the whole 
subject with the inguinal canal in its healthy state, and its pos- 
sibility of acquiring inguinal hernia. The conditions are 
analogous in the main, except as to size and the possible differ- 
ence in time required to produce a similar effect from a similar 
cause. 
In both instances we have a point of weakness about certain 
vessels and subjected to more or less pressure from within. In 
each we may have this weakness exaggerated-it may be any 
where from a slight to an extensive degree-by a funnel-shaped 
depression or cupping outwards which may be either congenital G. Edgar Dean, M.D. 
3 
or produced. It is easy to understand that a tolerably constant 
undue pressure may gradually increase the depth of this cup or 
broaden it, and thereby gradually increase the element of weak- 
ness ; or it may yield suddenly at the base and admit of a 
hernia de facto. 
In the case of the optic disc, we have in perfect health, as it 
appears, an exceedingly slight depression about the vena cen- 
tralis retina*, and also some less rigid tissue there, apparently 
intended by nature to afford greater safety to the vein Now in 
the highest state of nature, this slight depression has an area of 
elevation around it which acts as an excellent bulwark of pro- 
tection : but let it be subjected to a continued excess of pressure, 
slight though the accretion may be, as in the eye-strain of 
defective refraction, and we may observe that the interfibrillar 
substance of the nerve is absorbed, leaving a broad shallow cup 
(the atrophic cup of Fuchs); or, apparently independent of that, 
we may notice in other cases quite deep retrocession at the 
temporal side of the central vein without any very noticable 
lowering of the general surface of the optic disc. In the 
former cases (atrophic) there is apt to be also atrophic change 
at the periphery of the disc, while in the latter cases this 
factor is at least not so noticeable. 
I am disposed to regard both those conditions as intermediate 
stages between a healthy condition of the nerve on the one 
hand and glaucoma on the other ; more especially as I have 
seen inflammatory glaucoma in an eye with one of the deep 
narrow cups and a decided tendency towards glaucoma simplex 
in another, and because it appears that atrophy of this kind 
favors the developing of glaucomatous cupping. The optic 
nerve is placed very much like the cork in a wine bottle, i. e., as 
if forced in, so that outwards and inwards it is larger than in 
the middle ; hence an atrophy which reduces its diameter tends 
to make it push out more readily, thus displacing the lamina Early Management of Glaucoma. 
4 
cribrosa backwards and admitting of the well-marked glauco- 
matous cupping. 
Having given a brief resume of the course of utterly unbias- 
ed reasoning which led up to the conclusion, though without 
introducing the cases, which would be interesting enough if time 
permitted, we shall unhesitatingly announce the prime underly- 
ing cause of the disease 
The key-note of glaucoma is eye-strain; and that usually 
from some defect of refraction. 
There is no need to make a great mystery out of glaucoma 
any longer. If it were possible to correct all the errors of 
refraction in a given community, correct them early and keep 
them continually corrected by suitable and absolutely accurate 
glasses, then in that community, glaucoma apart from a few 
secondary and traumatic cases, would disappear. We speak 
advisedly in saying a few, for it is highly probable that these 
cases have largely been predisposed to by eye-strain. We 
apprehend that the elucidation of this subject has been delayed 
somewhat through reverence for the opinions of the immortal 
Graefe. It is indeed a high tribute to his genius that his 
doctrine on the subject should have been accepted as the law 
governing research almost up to the present time. Graefe did 
wonderfully well-as well as it was possible to do in his day ; 
but the age is progressive and the greatly improved refraction 
work, at least of some of the more careful men in this country, 
makes it possible to take a deeper and more comprehensive 
view into the etiology of this and certain other diseased 
conditions of the eye. 
Our object should not be to combat the theory of this or that 
individual, but to lay a foundation under them. Some of them 
at least, and perhaps most of them, contian good material and 
make such a presentable showing that they deserve to have 
something better than mist to stand upon. G. Edgar Dean, M.D. 
5 
While we have already been laying considerable stress upon 
back pressure, and while we believe that in the average case the 
posterior portion of the eye earlier receives the impression 
which tends in the direction of glaucoma, we must never lose 
sight of the general truth that eye-strain, the cause, is bi-polar in 
its action; hence we must comprehend the effects produced 
both posteriorly and anteriorly, and must not be surprised nor 
disconcerted by the variations in type met with in studying the 
disease, ft is but natural that when a force acts in more 
directions than one, the manifestations produced may vary in 
character. Of course in speaking of posterior strain, we are 
referring to that which takes place in and about the optic disc ; 
and of anterior strain, referring to that which occurs in and 
about the ciliary region, including a tolerably large and 
important area. 
We further must not ignore the fact that there is lateral 
pressure as well, and that the venae vorticosae are important 
elements in the circulation of the eye. And perhaps there has 
not enough stress been laid upon the ease with which the retro- 
choroidal lymph space may become affected. 
Concerning the effects of anterior pressure, it is not necessa- 
ry to say much here, for the reason that it is so well described 
in the text books. Most of them doubtless attribute undue 
importance to disturbances in Schlemm's Canal, as etiological 
factors; they are important enough to be sure, but it should be 
borne in mind that there are other and larger lymph channels in 
the eye. A close observer may notice that in a great many 
cases, interference with filtration in that direction is the final 
act of a rather long ocular tragedy. 
A strong argument that the early pressure effects are not so 
much forwards as backwards, is that so little scleral congestion 
is observable in the inflammatory cases compared to what is 
seen in iritis, cyclitis, etc. 6 
Early Management of Glaucoma 
No wonder the scientist looked in vain for the cause during 
the attack, when the cause has been acting more or less quietly 
for years until the attack obscured it, and rendered critical 
study impossible. 
It should be remembered that in thousands of non-glaucoma- 
tous cases the same cause (eye-strain) is acting, but finds 
enough resistance to prevent a glaucomatous effect from being 
produced. 
The optic nerve often withstands the strain so long and with 
so little local deleterious effect that we can but mirvel at its 
power of endurance. And even when some retrocession has 
occurred, oftentimes no startling symptoms arise until the lamina 
cribrosa has been forced back to such an extent that the pressure 
in part is applied in a lateral direction almost directly upon the 
nerve-sheath, upon the lymph channel surrounding it and, some- 
what less directly, upon the posterior ciliary circulation. 
Likewise forward pressure in the ciliary region (i. e., practi- 
cally in the opposite pole) is endured fairly well until it causes 
an impingement upon the absorbent angle of the anterior 
chamber. 
But it will be observed that these are only climaxes in a 
process long since begun. 
It is highly probable also that in a considerable percentage 
of cases, strain at one pole is endured until too much strain is 
applied at the opposite pole ; then the patient, suffering eye 
succumbs to overwhelming forces. In another of the diseases 
to which flesh is heir, viz., peritonitis, we have what may answer 
as an example in some respects of what is meant. So long as a 
peritonitis (non purulent) remains localized, it may seem 
comparatively insignificant, but let it assume a general form 
and all will admit its gravity. 
Space will not here admit of going exhaustively into the 
subject of eye-strain, but a few points may be briefly touched G. Edgar Dean, M.D. 
7 
upon. We shall premise by saying that the term has too often 
been restricted in many minds, almost entirely to the apparatus 
of accommodation, rather ignoring the important part played 
by the recti muscles. 
It is true that, apart from myopic eyes, a large percentage of 
the strain comes from near work, and hence glaucoma, as a fully 
developed disease, is largely confined to persons of more or less 
mature years, when the eyes find some added resistance to the 
efforts of accommodation. It accounts also for its relatively 
greater frequency in hypermetropes. We should not be 
surprised to find, if sufficient statistics were available, that the 
average onset was a little earlier in hypermetropes than in some 
other classes of cases, just as we notice in them the relatively 
earlier necessity of wearing glasses for reading. 
A very possible reason why myopic eyes are less frequently 
glaucomatous arises from the fact that many of them do not 
find much difficulty of accommodation. Another factor is found 
in the general weakness of the posterior wall of the globe, 
making the excess of pressure relatively less felt at the disc 
than in hypermetropic cases. 
Understanding that astigmatism is one of the greatest causes 
of eye-strain, we must consider that the ideal eye for the 
production of glaucoma, would be one with hypermetropic 
astigmatism. 
It is known to be rather frequent in such eyes, and doubtless 
a great many glaucomatous eyes classed simply as hypermetro- 
pic, really had a slight astigmatism which was undiscovered. 
Statistics show that very few emmetropic eyes have been 
affected with glaucoma, so few indeed that it is exceedingly 
probable that they were cases of mistaken diagnosis. 
If space permitted, we would refer to general conditions of 
the circulation and the system at large; to tonic spasm of the 
cilliary muscle, intra-nasal pressure, etc., as possible etiological 8 
Early Management of Glaucoma. 
factors. For the reason indicated, it is impossible here to give 
a detailed explanation of our view's regarding the mechanism of 
eye-strain. 
If the pathologist will take his cue from the clinical facts that 
eye-strain is the general underlying cause of glaucoma, and, 
further, that the earlier effects, so far as tending towards 
glaucoma are concerned, may be exerted backwards quite as 
frequently as forwards-perhaps far more frequently-,he will 
soon find that the study of this disease does not lead him into 
such a mystical field as it has been pronounced by most of our 
authors. 
If then he will turn his attention to the admirable schematic 
cut in Fuschs' "Text-book of Ophthalmology" (page 251) showing 
the lymph passages of the eye, and, observing how extensive 
they are, decide to make a general study of them in connection 
with glaucoma, he may find a rich field for investigation, and 
produce some decidedly definite results. 
EARLY MANAGEMENT OF GLAUCOMA. 
It has been thought best to refer to the plan of treatment 
provisionally adopted as the " early management of Glaucoma" 
for the reason that it applies primarily to those cases of 
Glaucoma and threatened Glaucoma, which early come under the 
observation of the oculist; and it would be manifestly unfair to 
apply it only to a few neglected and desperate cases found in 
metropolitan hospital practice, and then reject it as unworthy. 
Of course, in this disease even more than most others, preven- 
tion is better than cure. The chief measure of prophylaxis is 
the early use of acurate glasses ; but medication is also useful 
in that direction. The medication must, however, be followed 
up by glasses, and no pains must be spared to make them exact. 
Of therapeutic measures perhaps the best we have as yet 
found are acetanalid internally, pilocarpine solution instilled into 
the eye, and the hot solution of boracic scid applied externally. G. Edgar Dean, M.D. 
9 
The acetanalid has mostly been given in eight grain doses, 
three or more times a day to the average adult, and four grain 
doses to specially susceptible females. Its action should be 
watched so that it shall not cause too great depression; and if 
the temperature is found sub-normal, the dose should be lessened. 
My reasons for preferring pilocarpine to eserine are two-fold : 
first, that while it may not be so strong a myotic, it seems to 
have a better effect in reducing cilliary congestion ; secondly, it 
allays pain instead of causing it, as eserine does. 
We know of no reason why the strength of the solution should 
not be increased in critical cases, but 4 gr. ad 5i is as strong as 
we have used. Whether the salicylate of sodium does good of 
itself, we cannot say positively, but at any rate it preserves the 
solution, and we have sometimes fancied that the pilocarpine 
solution was more efficacious when combined with it. So we 
invaribly use it at the rate of ten grains to the fluid ounce. 
Very possibly it may be found that hypodermic injections of 
pilocarpine (| gr.) may be of service, but I have thus far never 
used them in this connection, preferring to rely upon acetanalid 
as internal treatment. Unless the patient were kept in a 
recumbent position and the circulation and temperature noted, 
it would not be safe to make use of both these depressing agents 
at once. Perhaps we may find cases wherein this, as in so many 
other diseases, the recumbent position is highly advisable ; but 
oftentimes the pain is of such a character as to make the patient 
restless instead of causing him to seek repose. 
For the hot external applications the patient was allowed to 
make an extemporaneous solution of boracic acid ; but the mode 
of applying was as specific as possible. They were made with 
soft cloth dipped frequently (once a minute), kept at about the 
highest comfortable temperature, and continued twenty minutes 
each time. The frequency of repeating them varied with the 
case from once a day to every three hours or oftener. 10 
Early Management of Glaucoma. 
We had hoped to obtain favorable results from the use oi 
gelsemium, but, at least in the dose employed, it did not yield 
as favorable results as acetanalid. 
The early employment of temporary glasses is a measure not 
to be neglected in certain cases ; for in these irritable eyes a 
sensible man will not attempt a great amount of subjective 
testing for glasses; and we doubt if many cases retain the same 
refraction when the acute and sub-acute symptoms have passed, 
that existed during those stages. 
Regarding iridectomy in this disease, we are confident that 
it is an operation which will fall more and more into disuse. It 
was an empirical operation at best, and though it served a very 
useful purpose in its day, it has comparatively little place in 
attending to the better cared-for eyes of the present. While it 
may still remain a desirable procedure for urgent or neglected 
cases, it does not always produce satisfactory results, and should 
by no means be lightly adopted as routine practice. 
For valuable aid in the preliminary work of this paper, I am 
indebted to my friends Dr. C. E. Conner, of Scranton, and Dr. 
W. A. Shoemaker, of the New York Eye and Ear Hospital. 
As intimated in the closing remarks, the clause in my paper 
refering to iridectomy was made more as a prophecy for the 
future than a statement of present practice. 
The operation is at present more or less "an empirical one ", 
but I trust that it will one day become a truly scientific one, 
confined within its proper limits 
Let him who would criticise the statements I have made first 
study his suspicious cases in the region of the optic disc with 
a Morton's ophthalmoscope ; for I doubt if this paper would 
have been written had I not been the possessor of that admira- 
ble instrument. 
NOTE-(not read at Washington).