Acute primary ischemic iris atrophy.

Five patients are described with acute primary ischemic iris atrophy with almost complete loss of the normal radial vessels of the iris and fine microneovascularization. The atrophy of the iris was marked with a thin atrophic stroma, widely dilated pupil, and extensive loss of pigment from the posterior surface of the iris. The condition is of unknown etiology but occlusion of the greater vascular circle of the iris is possible. Iris angiography showed an almost total loss of the radial vessels of the iris with some patchy microneovascularization. In recent cases, the onset was acute and all patients had a raised intraocular pressure (IOP) except one who had already undergone a drainage operation. There was an accompanying low-grade uveitis or cyclitis in the chronic stage in all cases. The condition was unilateral and the posterior segment of the eye was normal so that good visual function was possible if the accompanying cataract and glaucoma were appropriately managed.