Laser therapy for central retinal vein obstruction.

The Collaborative Central Retinal Vein Occlusion Study has recently reported information on the early natural history of central vein occlusion that includes a 16% conversion of perfusion to nonperfusion within the first 4 months. The Collaborative Central Vein Occlusion Study randomized trial of laser photocoagulation for macular edema and for the management of iris neovascularization suggested that grid laser photocoagulation is not useful for the improvement of visual acuity that is decreased because of perfused macular edema and that iris neovascularization is best managed by applying panretinal photocoagulation after the first appearance of iris neovascularization. A recent report has suggested that chorioretinal venous anastomosis can be achieved in some patients with vein occlusion to permit venous outflow through the choroid, lessen the likelihood of progression to ischemia, and improve visual acuity by lessening macular edema.