Branch Retinal Artery Occlusion (BRAO)

Branch retinal artery occlusion is a sudden blockage of one of the smaller arteries supplying the retina, causing loss of part of the vision in one eye.

Common symptoms

Sudden, painless loss of a patch of vision in one eye, typically corresponding to the area supplied by the blocked vessel.

Description

BRAO occurs when a branch of the main retinal artery is blocked, usually by a small clot or piece of plaque that has travelled from the neck arteries or the heart. The retina supplied by that branch loses its blood supply and stops working within minutes.

Unlike a central artery occlusion, only part of the visual field is affected, so vision in the rest of the eye is preserved. Because the cause is similar to a stroke, urgent medical assessment is needed to identify and manage risk factors and protect the other eye and the brain.

Vision already lost is often permanent, but treatment focuses on finding and treating the underlying cause. Blood pressure, cholesterol, and heart rhythm are commonly investigated, and low vision support can help adjust to any lasting change in vision.