[Effect of pan-retinal photocoagulation in iris neovascularization]

The authors were able to produce experimental rubeosis iridis in the rhesus monkey's eye on 5 days following occlusion of the major retinal vessels and persistent ocular hypotony. Histopathological examination revealed true neovascularization. This experiment attempted to see whether laser pan-retinal photocoagulation plays an inhibiting effect on the occurrence of rubeosis iridis or not. We first performed laser pan-retinal photocoagulation, and at the same time performed occlusion of the major retinal vessels and persistent hypotony to aid for rubeosis iridis. Clinically, rubeosis iridis appeared within 5 days. At 14 days, histological examination revealed vessels on the surface of the iris following pan-retinal photocoagulation treatment were covered by fibroblast and melanocyte, and their endothelial cells showed no fenestrations. This means that clinical rubeosis iridis is not true neovascularization, but dilatation of the iris vessels. Thus, it was confirmed that pan-retinal photocoagulation inhibits development of iris neovascularization.