What is a Retinal Vein or Artery Occlusion?
There are blood vessels, like pipes, to deliver blood to and drain blood from the retina, called arteries and veins respectively. In some people, one or the other can be blocked causing loss of vision. A retinal artery occlusion will cause sudden loss of vision while a retinal vein occlusion may take longer to affect your vision. Risk factors for these conditions are:
- Hardening of the arteries (Atherosclerosis)
- Diabetes
- High cholesterol or fats in the blood
- High blood pressure (hypertension)
- Other eye conditions, such as glaucoma
- Inflammatory diseases such as Giant Cell Arteritis (inflammation of arteries)
- Increased risks for blood clots
Because these conditions are more common as you age, it often affects older people. Blockage of retinal veins may cause other eye problems, including glaucoma (high pressure in the eye), bleeding in the eye and swelling of the central retina.
How is a retinal vein occlusion treated?
When retinal veins occlude, it cannot drain blood out of the eye. Blood and the contents of blood (mostly water) get trapped in the retina or vein upstream of the blockage (like a clogged toilet). This usually causes swelling of the retina, especially in the macula. Medications injected into the eye can tighten the blood vessels and significantly reduce retinal swelling leading to significant improvement in vision for most patients. These treatments however, do not cure the blockage, so continuous treatments are often necessary. Moreover, monitoring for development of new, abnormal blood vessels are needed over time because they can lead to bleeding inside the eye or very high eye pressures. If they develop, a laser treatment (usually in the office) will be recommended.
As importantly, the risk factors for this condition need to be assessed for each patient and communication with their primary health provider is required to ensure the health of not only the eyes, but the entire body.
How is a retinal artery occlusion treated?
This condition is an actual stroke in the eye itself. If a patient presents within the first four hours of sudden vision loss from a retinal artery occlusion, several options can be tried. A massage of the eye and reduction in eye pressure, by quickly removing fluid from the eye or with eye pressure lowering drops, are easy and quick treatments to try. Hyperbaric oxygen and intravenous TPA (clot buster) are other options if available. Unfortunately none of the above options and others have shown to consistently bring back vision for most patients. Moreover, there is no cure for retinal artery occlusions after it happens.
More importantly, the risk factors for a stroke need to be assessed for each patient and communication with their primary health provider is required to ensure the health of not only the eyes, but the entire body. Usually a full workup for a stroke in the emergency room is recommended within a week or two of the beginning of symptoms. If symptoms have been present for longer, an outpatient workup is usually sufficient. The workup can include an MRI with contrast to evaluate for a stroke in the brain; about one in four patients will also have a concomitant brain stroke. Carotid dopplers or angiograms as well as some blood work may be done to determine the risk factors as stated above. Seeing a neurologist, who specializes in strokes, is also recommended.