Retinal Vein Occlusion is a blockage of the blood vessels that drain out of the retina. Complications of retinal vein occlusion which threaten vision include neovascularization(growth of new blood vessels)and macular edema ( accumulation of fluid "leaking" from abnormal blood vessels). Currently, the treatment of retinal vein occlusion is laser photocoagulation. This treatment has found to have limited use in this type of condition.Anecortave Acetate is being considered as an attempt to control the growth of the abnormal blood vessels.