Progression of nonischemic central retinal vein occlusion.

Progression of nonischemic central retinal vein occlusion (CRVO) to ischemic CRVO occurs in up to 5-20% of patients with nonischemic CRVO. Eyes presenting with nonischemic CRVO and exhibiting an increase in intraretinal hemorrhages together with angiographic findings of aggravation of venule wall staining were assumed to be showing early signs of progression. Eight eyes of 7 patients were followed prospectively and when they exhibited signs of progression they were assigned to either follow-up or early laser treatment. Four eyes received grid and early panretinal laser photocoagulation. Three of them showed regression of retinopathy and 1 eye progressed to ischemic CRVO. The other 4 eyes did not receive early panretinal photocoagulation; 2 of them received no laser treatment at all and the other 2 received only grid laser photocoagulation. All of these 4 eyes progressed to ischemic CRVO.