Branch retinal vein occlusion (BRVO) is a blockage of one of the smaller branch veins draining the retina, usually at an arteriovenous crossing. It causes sectoral changes in the retina and can lead to visual blurring, particularly if the macula is involved.
Causes and Features
Like central occlusion, branch occlusion is associated with systemic vascular risk factors such as hypertension and atherosclerosis. The affected retinal quadrant shows haemorrhages, dilated and tortuous veins, and areas of ischaemia downstream from the blockage.
- Often presents with partial field defects or distortion rather than complete vision loss
- Macular oedema is the main cause of reduced central vision
- Neovascularisation can occur at the borders of ischaemic retina
- May be detected incidentally in asymptomatic individuals during routine examination
Management
Management aims to treat macular oedema, usually with intravitreal anti-VEGF or steroid injections, and to reduce the risk of neovascular complications. Systemic evaluation and control of blood pressure, cholesterol, and other risk factors are recommended.
- OCT imaging monitors changes in macular thickness and guides treatment intervals
- Sectoral retinal laser may be used if problematic new vessels develop
- Visual outcome is often better than in central occlusion but depends on macular involvement
- Ongoing follow-up is needed, particularly in the first year after the event
