Acute choroidal ischemia as a complication of photocoagulation.

Acute choroidal vascular insufficiency as a complication of photocoagulation has been little noticed. In 17 eyes of 16 patients photocoagulated with either xenon or argon sources for proliferative sickle cell retinopathy, gray lesions of the fundus developed peripheral to the photocoagulation sites. Histologic examination of similar gray lesions produced in monkeys showed necrosis and atrophy of the outer half of the retina. Intense photocoagulation of the human fundus, even with smaller spot sizes, may occlude a choroidal artery, producing separate gray lesions of distinctive shape. The lesions in both the patients and the monkeys progressed to granular hyperpigmentation by two to three weeks after photocoagulation.