Retinal Vein Occlusion
A Retinal Vein Occlusion (RVO) occurs when a vein in the retina is blocked which may cause swelling, bleeding and ischaemia (loss of blood supply) of the retina. Usually, it is caused by the hardening of the small calibre retinal blood vessels by conditions such as hypertension and elevated cholesterol.
There are two different forms of this condition, a Central Retinal Vein Occlusion (CRVO) involves the main retinal vein and a Branch Retinal Vein Occlusion (BRVO) involves a smaller branch vein. Vision loss can occur from swelling at the macula (macular oedema) or loss of retinal blood supply.