Central Retinal Vein Occlusion ( CRVO ) — Visual Disorder in Patients of Middle and Advanced Age —

Patients with central retinal vein occlusion (CRVO) have retinal hemorrhages in all four retinal quadrants around the posterior pole, with a markedly dilated and tortuous venous system. CRVO frequently develops in patients at 60–69 years of age, and approximately 90% of the incidence is noted in patients at 50 years of age or older. It usually occurs in one eye, but occasionally in both eyes if patients have an increased blood-viscosity condition, including hypervolemia and hyperlipemia. CRVO is generally associated with systemic complications, including hypertension and arteriosclerosis. Younger patients with CRVO principally caused by inflammation and blood disease often have favorable prognosis because their vision is improved by treating underlying diseases and using drug therapy. In nonischemic CRVO that develops in patients at 50–69 years of age, who had a specific level of vision at the onset of the disease, the prognosis varies according to whether arteriolar sclerosis is present, and to the duration of retina circulation time. In the absence of arteriolar sclerosis and delayed retina circulation time, visual acuity can be improved in most cases. In ischemic CRVO, which occurs in patients at 60–79 years of age who have poor vision at the onset of the disease, the condition is usually associated with arteriolar sclerosis and delayed retina circulation time, and thus the visual acuity is rarely improved. Laser photocoagulation is used to prevent the development of neovascular glaucoma.