Retinal vein occlusion occurs when a vein carrying blood supply away from the retina is blocked. The blockage most commonly occurs at an arteriovenous crossing, or where an artery overlies the vein. Hardened arteries, due to atherosclerosis or hypertension, can compress the vein, causing blockage. A blocked vein leads to obstruction of blood drainage from the retina, causing leakage of fluid. When this occurs close to the macula, known as the center of your vision, it can cause blurry vision and vision loss. There are two types of blockage: central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO). CRVO blockage occurs in the retina’s main vein and BRVO occurs in a small retinal vein.
A retinal vein occlusion can cause sudden, painless loss of part of your vision or central blurry vision. If the occluded vein is not near the center of your vision you may not have any symptoms.
Risk factors of retinal vein occlusion include:
High blood pressure
Rare causes in younger patients can include rheumatologic disease and blood clotting disorders
Treatment of Retinal Vein Occlusion
The treatment of retinal vein occlusions is primarily directed at systemic evaluation of factors that could cause the blockage. A thorough evaluation by your primary care physician is recommended to assess your blood pressure, cholesterol levels and other risk factors for heart disease. Medical treatment of any systemic risk factors will help prevent further vein occlusions.
Eye treatment is directed at treating the complications of the blockage rather than relieving the blocked blood vessel. The main reason for vision loss is swelling, or macular edema, at the center of your vision. This is often treated with intravitreal injections to stop abnormal blood vessel growth and swelling.