Aetiology of Glaucoma*

PAUL WEINSTEIN, M.D. (From the First Ophthalmological Clinic of the Peter Pdizmnadny University and the Albert Apponiyi Policliniic, Budclapest) From the time investigators first described glaucoma increased ocular tension has been regarded as its chief characteristic. But this increase in tension is really only a symptom, the causes of which are manifold. The current classification of glaucoma into inflammatory, primary, and secondary corresponds to clinical experience. This is confirmed by a series of more than 3,000 cases operated on at the First Ophthalmological Clinic. The common factor in the various forms of glaucoma is increase of ocular tension, but as these forms themselves differ in their clinical manifestations they necessarily differ also in pathogenesis. The earlier investigators believed the increase of tension to be due to an occlusion of Schlemm's canal at the so-called angle of the anterior chamber, by which stagnation is produced. The tendency of hypermetropes to develop glaucoma was similarly explained. But forms of glaucoma were discovered in which the depth of the chamber was normal (simple glaucoma and haemorrhagic glaucoma), this being proved by measurements taken by the slit-lamp and goniometer. Statistical data furthermore revealed that of the glaucoma patients 23 per cent. were emmetropic and 15 per cent. myopic, a proportion sufficiently large to convince investigators that general causes, as well as local alterations, must be concerned. It seems superfluous to detail the investigations which aimed at determining the influence of the acid-alkaline balance of the body, the internal secretion, the vegetative nervous system, and blood pressure on glaucoma development. Hertel's, and especially Imre's, observations concerning the influence of hypophyseal, thyroid, and ovarian secretion were very important; so was another aspect-that of the relation of glaucoma to the circulatory system.