A retinal vein occlusion occurs when a vein in the retina is blocked. The blocked vein damages damages the blood vessels of the retina, causing hemorrhages and leakage of fluid. There are two different types of retinal vein occlusion: Central Retinal Vein Occlusion and Branch Retinal Vein Occlusion. In a CRVO, the main vein of the eye becomes blocked. In a BRVO, one of the smaller branches of vessels becomes blocked.
Patients with diabetes, hypertension, glaucoma, age-related vascular disease and blood disorders are at risk of developing a vein occlusion.
Vein occlusions cause a painless decrease in vision, resulting in misty or distorted vision. Many patients will develop macular edema, or swelling in the central part of the retina. Current treatments for this include antiVEFG therapy (such as Avastin and Lucentis) and steroids (such as Ozurdex). If the veins cover a large area, new abnormal vessels may grow on the retinal surface, which can bleed into the eye and cause severely blurred vision. This may need to be treated with laser or surgery.
There is no cure for a vein occlusion. The current treatments are focused on preserving vision and reducing the chance of further vision loss. If you have had a retinal vein occlusion, regular visits to your ophthalmologist are essential to protect vision.