There is a difference of opinion in the ophthalmology community regarding whether prophylactic pan retinal photocoagulation should be applied to eyes with ischemic central retinal vein occlusions (CRVOs). Some investigators have recommended panretinal photocoagulation, while others have observed that panretinal photocoagulation is not helpful in preventing ocular neovascularization and neovascular glaucoma.1-4 Because of the diversity of opinions, the optimum treatment of a patient with ischemic CRVO is uncertain.
The Central Vein Occlusion Study (CVOS), a controlled clinical trial, was designed to determine whether prophylactic laser treatment is beneficial; patients are randomized either to undergo panretinal photocoagulation or to be observed without treatment. We believe that such randomization is the best and most ethical approach to the management of ischemic CRVO.
Eyes with at least 10 disc areas of retinal capillary nonperfusion, as established by the CVOS photographic protocol, are randomized to panretinal photocoagulation or observation. Both groups are being
Clarkson JG. Photocoagulation for Ischemic Central Retinal Vein OcclusionCentral Vein Occlusion Study. Arch Ophthalmol. 1991;109(9):1218-1219. doi:10.1001/archopht.1991.01080090042024