ABSTRACT
Retinal vein occlusion is the second most common retinal vascular disorder after diabetic retinopathy, with a prevalence of 0.1% for people aged between 43 and 84 years. 1 Depending upon the area of nonperfusion on fluorescein angiography, central retinal vein occlusion (CRVO) (Fig. 41.1) may be classified as either nonischemic (<10 disc areas) or ischemic (°[H11091]10 disc areas). Unfortunately, the natural history of the disease is unfavorable, with 50% of nonischemic eyes and 93% of ischemic eyes eventually having a visual acuity of 20/200 or less (legal blindness). Loss of vision may be caused by extensive intraretinal hemorrhages, retinal edema, capillary nonperfusion, or neovascular glaucoma. 2–;4 Currently, there is no known safe and effective treatment for CRVO. The Central Vein Occlusion Study (CVOS) provided guidelines to treat the sequelae of venous obstruction rather than the underlying occlusive event. In this study, panretinal laser photocoagulation reduced neovascular complications, but grid laser treatment did not improve visual outcomes as it had in the Branch Retinal Vein Occlusion Study (BVOS), and thus is not recommended. 3 New treatment modalities have been aimed at either bypassing the occluded retinal vein or re-establishing retinal venous blood flow.
