The central retinal vein is a vein which drains blood from the eye so that it can return to the heart for reoxygenation. This vein is a very important part of the eye's anatomy, because it is the eye's only avenue of blood drainage, just as the corresponding central retinal artery is the eye's only source of fresh blood. Damage to either the vein or the artery can lead to very serious problems, including permanent vision loss. This is one reason why regular eye exams are recommended, so that emerging problems within the eye can be identified before they become serious.
The vasculature of the retina includes a series of capillaries which connect to the central retinal vein. Depending on someone's anatomy, the vein may connect to the superior ophthalmic vein, which drains into the cavernous sinus, or the central retinal vein may connect directly to the cavernous sinus for drainage. From there, the deoxygenated blood works its way down to the heart and lungs, where it will be reoxygenated and recirculated.
Medically, the most common problem with the central retinal vein is an occlusion, a fancy way of saying “blockage.” Occlusions in the central retinal vein are often caused by clots, and are associated with elderly patients. In some cases, the occlusion leads to swelling, which can eventually cause retinal detachment, and in others, it deprives parts of the eye of oxygen, leading to vision loss because cells die when they are not getting enough oxygen.
When someone experiences sudden and painless vision loss, central retinal vein occlusion may be a likely culprit. Unfortunately, treatment options are limited, because by the time vision loss occurs, the damage has been done. An ophthalmologist can perform an assessment to determine the extent of the damage and make treatment recommendations on the basis of the results of the examination.
Some people are at increased risk of developing blockages in their central retinal veins. Individuals with clotting disorders, for example, are prone to developing clots which can lead to occlusion. Diabetics are also at risk, as are people with high blood pressure, and people with a history of glaucoma. Patients in these risk groups may be encouraged to make regular visits to a doctor to check on eye health so that problems can be identified as early as possible. If intervention is provided early for a central retinal vein occlusion, it may be possible to retain some vision.