Only one central vein drains all the blood from the retina. At the point where this vein leaves the eye, it shares a common wall with the central retinal artery. The vein may become blocked in a number of ways. Because of its close association with the artery, the vein may become occluded as a result of any disease affecting the arterial wall. Other systemic problems that can lead to C.V.O are diabetes, high blood pressure, and certain rare blood disorders.
Patients are usually in good health prior to the onset of the occlusion.
Several eye problems are related to C.V.O, including glaucoma, optic nerve abnormalities and localized arterial disease in the retina itself. A profound painless loss of vision usually accompanies closure of the retinal vein. In most, this vision loss is sudden and worsens over a few days. Only with time may the vision improve. There is no known treatment that is effective for this problem.