{"id":16473,"date":"2021-07-28T12:28:32","date_gmt":"2021-07-28T12:28:32","guid":{"rendered":"https:\/\/www.optometrists.org\/?page_id=16473"},"modified":"2021-12-13T11:45:37","modified_gmt":"2021-12-13T11:45:37","slug":"branch-retinal-vein-occlusion","status":"publish","type":"page","link":"https:\/\/www.optometrists.org\/general-practice-optometry\/guide-to-eye-conditions\/guide-to-retinal-diseases\/branch-retinal-vein-occlusion\/","title":{"rendered":"Branch Retinal Vein Occlusion"},"content":{"rendered":"

Over 13.9 million adults are affected by branch retinal vein occlusion (BRVO) globally.<\/b><\/h2>\n

Blood is carried throughout your body, including your eyes, through arteries and veins. One main artery and one main vein provide all the oxygen and nutrients for the retina of the eye.<\/p>\n

Branch retinal vein occlusion (BRVO)\u00a0<\/b><\/h2>\n

BRVO is a retinal disease<\/a> which occurs when the branches of the retinal vein become blocked.<\/p>\n

Blood and fluid leak out into the retina when a vein is blocked. This fluid might cause the macula to expand, compromising your central vision.<\/p>\n

Without venous blood circulation from the retina, retinal disease will occur<\/a> as the nerve cells die and eyesight deteriorates.<\/b><\/p>\n

What causes BRVO<\/b><\/h2>\n

The majority of blockages resulting from BRVOs occur at an arteriovenous crossing, the place on the retina where a retinal artery and vein cross over each other.<\/p>\n

At this cross-over point both vessels share a common sheath (connective tissue), and the vein becomes constricted when the artery loses flexibility due to atherosclerosis or hardening of the arteries.<\/p>\n

The turbulent blood flow in the restricted vein encourages clotting, resulting in a blockage or occlusion. This obstruction prevents blood flow, resulting in fluid leaks in the macula (macular edema) and ischemia (low blood flow) in the blood vessels supplying the macula.<\/p>\n

The common risk factors for BRVO are:<\/p>\n