The retina, or tissue in the back of the eye that converts light images to nerve signals and sends them to the brain, needs a constant supply of blood in order for oxygen and nutrients to function properly. There is a network of arteries that carry blood to the retina and veins that drain blood. If the retina veins become blocked, it leads to hemorrhages and fluid leakage. This is known as retinal vein occlusion.
What Causes Retinal Vein Occlusion?
There are two types of retinal vein occlusion: central retinal vein occlusion, which occurs in the main vein of the retina, and branch retinal vein occlusion, which occurs in the smaller branch veins. Most cases of retinal vein occlusion are caused by hardening of the arteries or by blood clots. Or, in some cases the veins of the eye are simply too narrow. Other health conditions and eye disorders — including diabetes, high blood pressure, high cholesterol and glaucoma — can raise the risk of developing retinal vein occlusion.
When the retinal veins are blocked, it can lead to other eye problems, including glaucoma and macular edema. In glaucoma cases, new and abnormal blood vessels grow in the front portion of the eye, causing high pressure conditions. Macular edema is a swelling of the macula, or the central portion of the retina responsible for sharp central vision.
Symptoms
Symptoms of retinal vein occlusion can range on a spectrum of subtle to obvious. Vision may be mildly blurry and worsen over a few days. Or, complete vision loss can occur spontaneously. In any case, symptoms require immediate medical attention. Retinal vein occlusion can lead to more serious conditions that cause permanent retinal damage, irreversible vision loss and other problems. Ignoring symptoms could have long-standing consequences.
A trained ophthalmologist or retina specialist can diagnose retinal vein occlusion during an eye examination. The eyes are dilated to get a closer look at the retina, and visual acuity is measured. Optical coherence tomography provides detailed images of the retina to identify areas of thickness and swelling. Or, a fluorescein angiography is performed to take a closer look at the blood vessels. During the test procedure, special dye is injected into the arm and travels to the blood vessels in the retina. Photographs are taken to look for blockages in the blood vessels.
Treatment for Retinal Vein Occlusion
Retinal vein occlusion does not always require medical or surgical intervention; for many people, useful vision returns without any treatment. There currently is no way to reverse or clear blood vessel blockage. However, there are ways to treat the complications associated with retinal vein occlusion. For example, laser treatment can help to reduce the swelling, or prevent the growth of new abnormal blood vessels. Another way to limit the growth of new blood vessels is through the injection of anti-vascular endothelial growth factor drugs. Corticosteroid drugs can also be injected into the eye to control swelling that could lead to edema.
Regular appointments with an ophthalmologist are recommended to monitor the condition and watch for any changes. People that have been diagnosed with another blood vessel disease or that are at a high risk for developing one should be diligent about managing their condition. Taking medications as prescribed, following a healthy diet and regularly exercising are essential to support optimal health and avoid conditions such as retinal vein occlusion.
Have you been diagnosed with diabetes, high cholesterol or high blood pressure? Hopefully you are staying on top of your eye health with regular exams. If an exam has turned up any problems with your retina, including retinal vein occlusion, we can help you explore your treatment options. Please contact us today to request an appointment.