Anterior lens curvature. Comparisons between normal eyes and those with primary angle-closure glaucoma.

A pupil-block angle-closure glaucoma hypothesis was submitted by Curran (I920, I931), who observed that after iridectomy for acute glaucoma the iris hugged the lens much more closely and extensively than after iridectomy before cataract extraction. Rosengren (I 93 1) showed the association between shallow anterior chambers and acute congestive glaucoma. Following the gonioscopic investigations by Barkan (1938, 954) and Sugar (I941) and the teachings of Chandler (I952), Curran's hypothesis became established and pupil-block angle-closure glaucoma became defined as a distinct disease. Various authors proposed mechanical explanations for the pupil block (Sugar I964; Lowe, I966a; Mapstone, I968; Wyatt and Ghosh, I970). During the examination of a large series of eyes that had pupils dilated after peripheral iridectomy for the treatment or prophylaxis of primary angle-closure glaucoma, I was struck by the marked curvature of the anterior lens surface within the enlarged pupil. The lens frequently appeared as though it were herniating through the enlarged pupil with the pupil margin of the iris seeming to grip the lens. Investigations were therefore pursued to measure the anterior lens curvatures of a series of such eyes for comparison with a series of normal eyes from subjects of similar age.