Central Retinal Vein Occlusion (CRVO)

Central retinal vein occlusion (CRVO) refers to a blockage of the main vein that drains all of the blood from the eye. A CRVO is usually more severe than a BRVO, although milder cases do occur. In addition to causing loss of vision from macular edema or macular ischemia, a CRVO may predispose to the growth of abnormal blood vessels on the iris of the eye. These vessels can then grow into and close off the area that drains fluid from the eye. This condition is termed neovascular glaucoma, and can cause severe pain, loss of vision, and eventually lead to the loss of the eyeball itself.