Central Vein Occlusions
This is an unfortunate condition affecting the main vessels In the back of the eye. It usually occurs in elderly patients and permanently reduces vision in the affected eye.
The retina is the delicate, light—sensitive layer in the back of the eye. 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.
What Cause Central Vein Occlusion?
Arteriosclerosis (hardening of the arteries) is the most common cause of central vein occlusion. 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. The ophthalmologist's job is to establish a cause, if one can be found, and monitor the eye for any complications. The two most common complications are:
- New blood vessel growth on the surface of the retina. These new vessels, even though well—intentioned, are always abnormal and will lead to hemorrhages inside the eye if left untreated.
- New vessels may form on the colored part of the eye (iris). This condition is called rubeosis and may lead to a painful form of glaucoma and repeated hemorrhages in the eye.
There is no medical treatment for this condition. Early detection Is the key to treating the complications of C.V.O. Treatment with laser may be effective in maintaining vision and preventing further visual loss.
That is why, after a C.V.O., patients need to be frequently examined for several months. The final visual outcome Is dependent upon the extent of cell damage done at the time of the original occlusion and upon the results of any treatment done for the potential complications.