Dr. David Maberley, MD, FRCSC, Ophthalmologist

Duration: 2 minutes and 33 seconds

Retinal vein occlusion is a condition that occurs when the blood supply to the retina is damaged. The problem occurs when blood leaks into the back of the eye and then cannot leave due to a blockage in the vein. When this occurs the blood backs up into the retina and back of eye causing edema and damage.

When you've got a blockage in the retinal vein, what happens is the fluids in the blood and the blood cells themselves back up just like a dam in a river for example. Once this occurs and pressure begins to build, the blood then starts to leak out into the surrounding retina. At this point an ophthalmologist would see hemorrhages and fluid in the retina and the patient may see visual disturbances.

There are two types of retinal vein occlusion, central retinal vein occlusion and branch retinal vein occlusion. Central retinal vein occlusion is where the central vein that drains the eye becomes blocked and it's very difficult for blood to exit. This can affect the entire retina and subsequently can affect vision within the entire central and peripheral areas.

Branch retinal vein occlusion is where just a small part of the retina has a blockage which creates a small area where the blood cannot get out of the eye. This can affect smaller areas of a person’s vision.

Risk factors for this for central retinal vein occlusion tend to be the same risk factors for thrombosis in the rest of the body. People who have a higher risk of blood clots might be at higher risk of central retinal vein occlusion. Certain medicines, for example, hormonal pills or birth control can increase the risk of central retinal vein occlusion.

Branch retinal vein occlusion tends to be more related to high blood pressure and hardening of the arteries with age and is less associated with general clotting abnormalities. In terms of the symptoms, patients may experience blurry or loss of vision that can either come on suddenly or develop over a period of hours or days. If the blockage is very mild the patient may not experience any symptoms at all. In more severe cases, people can experience pain and pressure in the eye.

If you think you are at risk of retinal vein occlusion and would like to be screened for the condition, you should visit your local eye specialist.

Presenter: Dr. David Maberley, Ophthalmologist, Ottawa, ON

Local Practitioners: Ophthalmologist