Retinal vein occlusion

A retinal vein occlusion occurs when a vein in the eye’s retina is blocked.

The retina is the layer of light-sensing cells lining the back of your eye. It converts light rays into signals, which are sent through the optic nerve to your brain where they are recognized as images.

A blocked vein damages the blood vessels of the retina. Hemorrhages (bleeding) and leakage of fluid

occurs from the areas of blocked blood vessels.

There are two different types of retinal vein occlusion:

Central retinal vein occlusion (CRVO): when the main vein of the eye (located at the optic nerve) becomes blocked; and
Branch retinal vein occlusion (BRVO): when one of the smaller branches of vessels attached to the main vein becomes blocked