Retinal Artery Occlusion

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CRAO / BRAO

Most people know that high blood pressure and other heart diseases pose risks to your overall health. But many do not know that that high blood pressure can affect vision by damaging the arteries in the eye.

A retinal artery occlusion (RAO) is a blockage in one or more of the arteries of your retina. The blockage is caused by a clot or occlusion in an artery, or a build-up of cholesterol in an artery. This is similar to a stroke.

There are two types of RAOs:

  • Branch retinal artery occlusion (BRAO) blocks the small arteries in your retina.
  • Central retinal artery occlusion (CRAO) is a blockage in the central artery in your retina.

 

Symptoms and Risk of a Retinal Artery Occlusion

The most common symptom of a retinal artery occlusion (RAO) is sudden, painless vision loss. It can affect all of one eye, in the case of a central retinal artery occlusion (CRAO), or it can affect part of one eye, in the case of branch retinal artery occlusion (BRAO). Other symptoms include:

  • loss of peripheral vision
  • distorted vision, and
  • blind spots

If you have any of these symptoms, get medical help right away to help prevent vision loss.


Who Is At Risk for a Retinal Artery Occlusion (RAO)?

Men are more likely to have an RAO than women. The disease is most commonly found in people in their '60s. Having certain diseases increases your risk of RAO. These include:

  • cardiovascular disease;
  • diabetes;
  • high cholesterol;
  • high blood pressure; and
  • narrowing of the carotid arteries.

 

Diagnosis of a Retinal Artery Occlusion

If you experience sudden vision loss, you should contact your ophthalmologist immediately. He or she will conduct a thorough examination to determine if you have had a retinal artery occlusion. Your ophthalmologist will dilate your eyes with dilating drops. This will allow him or her to examine the retina for signs of damage.

Other tests your ophthalmologist may do are:

  • Fluorescein angiography. This imaging test uses a special camera to take photographs of the retina. A small amount of yellow dye (fluorescein) is injected into a vein in your arm. The photographs of fluorescein dye traveling throughout the retinal arteries show how many arteries are closed;
  • Intraocular pressure;
  • Reflexes of your pupil;
  • Other photos of the retina;
  • A slit-lamp examination;
  • Testing of side vision (visual field examination); and
  • Visual acuity (sharpness), to determine how well you can read an eye chart.

 

Treatment of a Retinal Artery Occlusion

 

Several treatments may be tried but none have ever been proven to help consistently. These treatments must be given within a few hours after symptoms begin to be helpful. Treatments include:

  • Breathing in (inhaling) a carbon dioxide-oxygen mixture. This treatment causes the arteries of the retina to widen (dilate);
  • Removing some liquid from the eye to allow the clot to move away from the retina;
  • A clot-busting drug.

Some patients regain vision after a retinal artery occlusion, although vision is often not as good as it was before. In some cases, vision loss can be permanent.