Branch retinal vein occlusion


Branch retinal vein occlusion is a common retinal vascular disease of the elderly. It is caused by the occlusion of one of the branches of central retinal vein.

Signs and symptoms

Patients with branch retinal vein occlusion usually have a sudden onset of blurred vision or a central visual field defect.
The eye examination findings of acute branch retinal vein occlusion include superficial hemorrhages, retinal edema, and often cotton-wool spots in a sector of retina drained by the affected vein. The obstructed vein is dilated and tortuous.
The quadrant most commonly affected is the superotemporal.
Retinal neovascularization occurs in 20% of cases within the first 6–12 months of occlusion and depends on the area of retinal nonperfusion. Neovascularization is more likely to occur if more than five disc diameters of nonperfusion are present and vitreous hemorrhage can ensue.

Risk factors

Studies have identified the following abnormalities as risk factors for the development of branch retinal vein occlusion:
Diabetes mellitus was not a major independent risk factor.

Diagnosis

The diagnosis of branch retinal vein occlusion is made clinically by finding retinal hemorrhages in the distribution of an obstructed retinal vein.
Several options exist for the treatment of branch retinal vein occlusion. These treatments aim for the two of the most significant complications, namely macular edema and neovascularization.
In general, branch retinal vein occlusion has a good prognosis: after 1 year 50–60% of eyes have been reported to have a final visual acuity of 20/40 or better even without any treatment. With time the dramatic picture of an acute branch retinal vein occlusion becomes more subtle, hemorrhages fade so that the retina can look almost normal. Collateral vessels develop to help drain the affected area.

Epidemiology