Central retinal vein occlusion is a blockage of the central retinal vein by a thrombus. It causes painless vision loss, usually suddenly. Diagnosis is by funduscopy. Most treatments are ineffective.
Major risk factors include
Other risk factors include
Occlusion may also be idiopathic. The condition is uncommon among young people. Occlusion may affect a branch of the retinal vein or the central retinal vein.
Neovascularization of the retina or iris (rubeosis iridis) with secondary (neovascular) glaucoma can occur weeks to months after occlusion. Vitreous hemorrhage may result from retinal neovascularization.
Symptoms and Signs
Painless visual loss is usually sudden, but it can also occur gradually over a period of days to weeks. Funduscopy reveals hemorrhages throughout the retina, engorgement and tortuousness of the retinal veins, and, usually, significant retinal edema. These changes are limited to one quadrant if obstruction involves only a branch of the central retinal vein.
The diagnosis is suspected in patients with painless visual loss, particularly those at risk. Funduscopy confirms the diagnosis. Patients with a central retinal vein occlusion are evaluated for hypertension and glaucoma and tested for diabetes. Young patients are tested for increased blood viscosity (with a CBC and other coagulable factors as deemed necessary).
Most patients have some visual deficit. In mild cases, there can be spontaneous improvement to near-normal vision over a variable period of time. Visual acuity at presentation is a good indicator of final vision. If visual acuity is at least 20/40, visual acuity will likely remain good, occasionally near normal. If visual acuity is worse than 20/200, it will remain at that level or worsen in 80% of patients.
There is no generally accepted medical therapy for occlusion itself. However, if neovascularization develops, panretinal photocoagulation should be initiated because it may decrease vitreous hemorrhages and prevent neovascular glaucoma.
Clinical trials are investigating intravitreal injection of corticosteroids and anti–vascular endothelial growth factor drugs.
Last full review/revision December 2008 by Sunir J. Garg, MD, FACS