What Is a Retinal Artery Occlusion?
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 60’s. Having certain diseases increases your risk of RAO. These include:
Diagnosis of a Retinal Artery Occlusion
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 (pressure inside the eye)
- Reflexes of your pupil
- Other photos of the retina
- A slit-lamp examination
- Testing of side vision (visual field examination)
- Visual acuity (sharpeness), to determine how well you can read an eye chart.
Since RAOs involve other aspects of your general health, your ophthalmologist will likely communicate with your primary care provider.
People who have RAOs are at a greater risk for having a stroke (when blood flow to the brain is cut off), so your ophthalmologist or your regular doctor may order an ultrasound of your carotid arteries (the main blood vessels in your neck that send blood to your eyes and brain). An ultrasound is a medical test that uses soundwaves to create images of the organs and tissues inside your body. You might also be told to have an echocardiogram (ultrasound of the heart). Both of these tests help look for a possible source of the blockage in the retinal artery.
Treatment of a Retinal Artery Occlusion
- 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 an RAO, although vision is often not as good as it was before. In some cases, vision loss can be permanent.