What is a Retinal Vein Occlusion?
Retinal vein occlusion (RVO) is a vascular disorder of the retina and is the second leading cause of blindness, behind diabetic retinopathy. An occlusion occurs when there is a blockage in the veins of the retina; veins carry blood away from the nerve cells in the eye. When a retinal vein is blocked, blood cannot be drained from the retina. As a result, hemorrhages and leakage of fluids from the blocked vessel may occur.
Are There Different Types of Retinal Vein Occlusion?
RVOs are classified based on the location of the occlusion. Central retinal vein occlusion (CRVO) occurs when the main retinal vessel is blocked. Branch retinal vein occlusion (BRVO) occurs when the blockage occurs in a smaller branch vein.
Patients with CRVO will usually experience blurry or distorted vision since it occurs in the central retinal vein that drains blood from the retina.
BRVO causes a sudden loss in vision that may go unnoticed if the affected vision is not central. Most BRVOs occur at the intersection of a retinal artery and vein. In atherosclerosis, the artery loses flexibility and the vein is compressed; this leads to turbulent blood flow that promotes clotting and occlusion which further leads to fluid leakage and ischemia.
Patients with uncontrollable hypertension, increased body mass index, cardiovascular disease, and glaucoma are at risk at developing RVO.
Is There Treatment for RVO?
There is no cure for vein occlusions but the main goal of treatment is to stabilizing vision by managing leaking blood vessels. If the retinal vein occlusion does not improve on its own, Dr. Narain may inject an anti-VEGF drug into the eye to reduce the growth of new blood vessels. Most patients will require multiple injections as the effects of the drug will diminish as it leaves the bloodstream. There are several anti-VEGF agents available to treat neovascularization and macular edema.
Dr. Narain may also perform a focal laser treatment to stop fluid from leaking from the vessels. The procedure is performed with topical anesthesia and is both safe and effective.