Gonioscopic studies in congestive glaucoma.

SINCE narrow-angle glaucoma was described by Barkan (1938), conflicting opinions have been expressed as to the correctness of his views. Barkan postulated, and many authors have since agreed with him, that the rise in intra-ocular pressure in the condition usually known as congestive glaucoma, is due to mechanical obstruction to the outflow of aqueous at the filtration angle of the anterior chamber by the apposition of the periphery of the iris to the corneo-scleral trabeculaeorto the cornea just anteriorly(Sugar, 1941; Haas and Scheie, 1952; Chandler, 1952). These authors believe that the anatomical configuration of the eye predisposes to this event and do not admit that the pre-existing shallowness of the anterior chamber has a dynamic pathological cause. Moreover, Rosengren (1950) has produced evidence to show that the depth of the anterior chamber in patients with congestive glaucoma does not vary appreciably if measurements are made before, during, or after an acute attack. Priestley-Smith (1883) showed that the lens increases in size with age, and Tornquist (1953) in a careful study, presented convincingevidence that shallowness of the anterior chamber per se may be an inherited characteristic. He also showed that the depth of the anterior chamber in relatives of persons known to have congestive glaucoma tends to be significantly less than in that of the general population. Although the relationship may not be precise, it is the opinion ofthe present author, as the result of gonioscopic studies, that shallowness of the anterior chamber is associated with a narrow filtration angle. There appear to be three schools of thought regarding the mechanism of the rise in intra-ocular pressure in congestive glaucoma. The adherents of the narrow-angle theory are of the opinion that the actual closure of the filtration angle is the result of some physiological event which only produces a pathological result (the rise in intra-ocular pressure) because ofthe pre-existing anatomical condition of narrowness of the angle. Various suggestions have been made as to the exact mechanism involved; Chandler (1952) and Haas and Scheie (1952) postulated a slight peripheral ballooning ofthe basal portion of the iris caused by a relatively higher hydrostatic pressure in the posterior chamber over that in the anterior chamber, the so-called physiological iris bomb6. Barkan in his original paper suggested a bunching of the base of the iris due to pupillary dilatation, and Sugar quoted a number of factors which