Branch retinal vein occlusion commonly occurs when a blood clot blocks a vein in the eye. This “clot” can be triggered by different factors: In most cases it is caused by an elevated blood pressure and the concomitant atherosclerosis (disease in which plaque builds up inside your arteries). But also smoking and diabetes constitute risk factors.
Depending on the exact location, we either speak of a branch retinal vein occlusion (BRVO) or a central retinal vein occlusion (CRVO).
Branch retinal vein occlusions are much more common than central retinal vein occlusions: In 85% of all cases of retinal vein occlusion, we will be dealing with a BRVO. In general, the risk of suffering a vein occlusion increases considerable with age. Nearly all patients are over 50 years old.