Central Retinal Vein Occlusion (CRVO)

Central retinal vein occlusion is a blockage of the main vein draining the retina, leading to sudden blurred or reduced vision in one eye.

Common symptoms

Sudden, painless blurring or loss of vision in one eye, sometimes with dark or distorted patches and occasionally with new floaters.

Description

CRVO occurs when the main vein carrying blood away from the retina becomes blocked, usually by a clot. Blood and fluid back up in the retina, causing swelling at the macula and damage to retinal cells.

The condition is most common in people over 50 and in those with high blood pressure, glaucoma, diabetes, or cardiovascular disease. A branch version, where a smaller vein is affected, can cause similar but more localised changes in vision.

Treatment aims to reduce macular swelling and prevent complications such as abnormal new blood vessels. Injections into the eye, laser treatment, and careful management of underlying health conditions are the main approaches, alongside monitoring to catch any changes early.