Retinal Vein Occlusion
Retinal vein occlusion occurs when one of the tiny retinal veins in the eye becomes blocked by a blood clot. This means that blood cannot drain away from the retina as easily and there is a backlog of blood in the blood vessels of the retina. This can lead to a build-up of pressure in the blood vessels. As a result, fluid and blood start to leak from the blood vessels, which can damage and cause swelling of the retina, affecting your eyesight.
There are two main types of retinal vein occlusion:
Branch retinal vein occlusion – the blockage occurs somewhere along the course of one of the four retinal veins. (One retinal vein drains each quarter of the eye.)
Central retinal vein occlusion – the blockage occurs in the main vein formed by the four retinal veins coming together.
Branch retinal vein occlusion is two to three times more common than central retinal vein occlusion.
The exact reason why a blood clot may form in one of the retinal veins is not clear. However, your risk of developing retinal vein occlusion seems to be increased if you have risk factors for cardiovascular disease. These include:
- High blood pressure
- High cholesterol
Patients with retinal vein occlusion usually notice a decrease in vision in one eye. Some people describe having a blind spot in one eye. The condition is mostly painless unless there are complications. Depending on the severity, retinal vein occlusions may cause only mild visual loss. However, in some cases they may cause extensive vision loss. Some people who only have a small blockage of a branch retinal vein may not have any symptoms.
In Phoenix, retinal vein occlusion is usually diagnosed after your doctor examines the back of the eye using a device called an ophthalmoscope. This is a hand-held instrument with a light and magnifier. He may also use a larger special light and magnifier called a slit lamp. Depending on the appearance of the retina, your doctor will usually be able to tell whether you have a central retinal vein occlusion or a branch retinal vein occlusion.
Various other tests may be suggested including measurement of your visual acuity (how well you can see) and your visual fields (to look at how good your side vision is).
Early diagnosis and treatment of retinal vein occlusion and any complications may make a difference to the eventual level of visual loss. However, severe retinal vein occlusions can cause permanent visual loss, even if treated very early.
If you have concerns about retinal vein occlusion or would like to schedule a retinal exam with one of our doctors, contact Associated Retina Consultants today at 602-242-4928 or associatedretinaconsultants.com.