Branch retinal artery occlusion (BRAO) is a rare retinal vascular disorder in which one of the branches of the central retinal artery is obstructed.^[1]

Abrupt painless loss of vision in the visual field corresponding to territory of the obstructed artery is the typical history of presentation. Patients can typically define the time and extent of visual loss precisely.^{[citation needed]}

Retinal whitening that corresponds to the area of ischemia is the most notable finding. In chronic phase the retinal whitening disappears.^{[citation needed]}

Risk factors include:^{[citation needed]}

• Hypertension
• Elevated lipid levels
• cigarette smoking
• Diabetes
• Susac's syndrome - This is one of the key symptoms of the disease.

Ancillary testing is not usually necessary to make the diagnosis. Fluorescein angiography reveals an abrupt diminution in dye at the site of the obstruction. Visual field testing can confirm the extent of visual loss.^{[citation needed]}

No proved treatment exists for branch retinal artery occlusion. In the rare patient who has branch retinal artery obstruction accompanied by a systemic disorder, systemic anti-coagulation may prevent further events.^[1]

The mean age of affected patients is 60 years. The right eye is affected more commonly than the left eye which probably reflects the greater possibility of cardiac or aortic emboli traveling to the right carotid artery. Most of the cases are due to emboli to the retinal circulation. Three main types of retinal emboli have been identified: Cholesterol, calcific, and fibrin-platelet.^{[citation needed]}

• Central retinal artery occlusion
• Central retinal vein occlusion
• Branch retinal vein occlusion