Short in length, the central retinal vein courses through the optic nerve. It carries blood away from the retina toward the heart.

The retina is a layer of tissue at the back of the inner eye. It is full of cone cells and rods, which transmit messages to the occipital lobe in the brain’s cerebral cortex. These messages give individuals the ability to tell the difference between light and dark, as well as colors.

When the blood flow into the central retinal vein becomes blocked, central retinal vein occlusion, or CRVO, occurs. This ailment, in its severe form, will cause a total loss of vision accompanied by pain. It is most commonly seen in middle-aged and elderly people, it affects over 60,000 people per year.

Primary open-angle glaucoma occurs when the pressure within the eye increases. People suffering from this type of glaucoma are at risk of developing CRVO. People who suffer from vascular diseases, such as high blood pressure, diabetes, and atherosclerosis, are also at risk.

When the retina becomes inflamed, retinal vasculitis occurs. This inflammation causes a clot formation called thrombosis, which can lead to central retinal vein occlusion.