Glaucoma | Page 4

of blood pressure in the heart and arteries. Clinical observations point the same way. Many patients connect their attacks (especially their earlier ones of ocular discomfort, impaired vision, haloes around the light, and dilated pupil) with social excitement, anxiety, worry, anger or fatigue. A patient of mine gave up her card parties, because an exciting game generally ended in blurred vision, a rainbow around the light, and a dilated pupil, and sometimes an aching eye. Another woman watching beside her dying husband and exposed to extreme cold, had her first attack of glaucoma, so severe as to destroy the sight of one eye. The other eye, also affected at the time, recovered good vision, and has remained several years without a second attack and without treatment.
Laqueur's first attack occurred at the end of a long exhausting morning in the operating room, with luncheon delayed two hours. The connection of his later attacks with anger, worry, embarrassment, even the excitement of watching a play at the theatre, was noted again and again. In Javal's case, the attack fatal to one eye came at the culmination of an exciting electoral campaign. The other eye was stricken at the termination of the Dreyfus case, in which Javal was intensely interested. There seems to be a special liability to glaucoma among those residing at high altitudes, best explained by nerve influence. The frequency of glaucoma among Jews may be due to a small cornea, as suggested by Priestley Smith; but it is quite as reasonable to connect it with a racial excitability or nervous instability. More definite knowledge of the nervous mechanism concerned in the regulation of intra-ocular pressure and the production of glaucoma is much needed.
Alterations of Fluids and Tissues
The influence of increased affinity of the tissues for fluid has already been referred to. That a similar obstacle to the escape of fluid from the eyeball might be due to a change of character in the fluid, is a conception that has been entertained as a working hypothesis, and much experimental and analytical work has been done to test its correctness. This work has been so slightly related to practical ophthalmology, and so contradictory in its results that alterations in the fluids can only be regarded as a possible etiologic factor. Glaucoma secondary to intra-ocular hemorrhage, operations on the lens or its capsule, or severe nutritional disturbance may be capable of such explanation.
Different Kinds of Glaucoma
A better grasp of the etiology of glaucoma may be attained by considering separately various types of cases; although perfectly typical cases may be rare; and cases of mixed type and etiology much more frequent.
Simple glaucoma has been recognized as closely related to atrophy of the optic nerve with deep excavation. No line of demarcation can be drawn between them, except by reserving the term of glaucoma for cases that depart from the pure type, terminating in glaucoma of some other kind, which is no more significant than the passage of a conjunctivitis into a keratitis, or an iritis into a glaucoma. Cases of simple glaucoma do run their course of many years to complete blindness, or to death, without exacerbations, inflammation, or characteristic pain. In such cases the intra-ocular tension does not rise suddenly; and it may be little or not at all elevated above the usual normal limit.
For nine years I have watched the progress of such a glaucoma in a man now aged 87, with slow development of glaucomatous cupping of the optic disc, now more than 3 D. deep. The tension has never been noted at more than Plus T (?), and when taken with the tonometer varied from 9 to 32 mm. for the worse eye, and 13 to 24 mm. for the other. Similar cases in which the tension lay within the commonly accepted normal limits have been reported recently by Bietti and Stock.
In the eye there is probably a normal equilibrium between blood pressure, tissue activity, and intra-ocular tension. This may be destroyed either by increasing the intra-ocular tension, or lowering the tissue activity, or the blood pressure. Lowered blood pressure has been suggested by Paton as an explanation of symptoms usually ascribed to vascular obstruction. Rising blood pressure may be required in old age to compensate for diminished tissue activity; and it is conceivable, under normal intra-ocular tension, that diminished nutritional activity may result in the same symptoms as are produced in other eyes by increased tension. Glaucoma is probably not so much an increase of tension as a loss of balance between intra-ocular tension and nutritional activity.
In contrast with the above are the cases marked by sudden elevations of ocular tension recurring repeatedly over long periods without permanent visual impairment. Laqueur's case continued of this character for six years, under the use of miotics, and then was cured by