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Retinal Artery & Vein Occlusion

What Is Retinal Artery & Vein Occlusion?

A retinal artery or vein occlusion, also known as an eye stroke, is a blockage of one of the blood vessels feeding the retina, which is the light-sensitive nerve tissue lining the back of the eye. A blockage results in a lack of oxygen getting to the nerve cells in the retina, which may result in drastic vision loss.

Blockages happen in the arteries supplying blood to the retina and veins that take blood away from the eye. These blockages involve most of the retina (central) or a portion of the retina (branch) are called:

Central retinal artery occlusion (CRAO)

This blockage of the main artery supplying blood (and oxygen) to the eye has the highest potential to cause the most damage to the eye, resulting in severe vision loss. In about 25 percent of people, the chance for extreme eye damage is lessened because they have an extra artery in their eye, called a cilioretinal artery. If the cilioretinal artery is not impacted by the blockage, damage to central vision is lessened.

Branch retinal artery occlusion (BRAO)

This is a blockage of one artery in the retina more in the retinal periphery. It causes severe loss of vision in that location but doesn’t typically affect the central vision.

Central retinal vein occlusion (CRVO)

This is a blockage of the main vein that drains blood from the retina and causes severe loss of vision as fresh oxygenated blood cannot get into the eye. This is more common than a CRAO and is associated with high blood pressure and diabetes. It is sometime accompanied by new blood vessel growth that causes a difficult to treat glaucoma.

Branch retinal vein occlusion (BRVO)

Blockages of the branches of the retinal vein are called branch retinal vein occlusions. These blockages cause blood and fluid to spill into the retina and cause swelling that impacts your ability to see. Over time, if the blood circulation is hampered, nerve cells in your eye may die and result in more vision loss.

Blockages are most often caused by blood clots, hardening of the arteries or when small pieces of cholesterol break off blood vessels.

Common risk factors for developing BRVO or CRAO include:

  • Age — Blockages happen more frequently in those older than 65.
  • Atherosclerosis — hardening of the arteries
  • Blood clotting disorders
  • Diabetes
  • Glaucoma
  • High blood pressure
  • Intravenous drug abuse
  • Obesity
  • Oral contraceptive usage
  • Pregnancy
  • Smoking


Retinal artery or vein occlusion is painless. It usually happens in one eye only and occurs more often in men than in women. It may come on suddenly or worsen gradually over several hours or days. Sudden loss of vision is an emergency, and you should contact a medical professional as soon as possible.

Common symptoms include:

  • Blurry or dimming vision — Objects both near and far may appear fuzzy or poorly defined.
  • Vision loss — Sudden loss of part or all vision may occur.

Treatment Options

Vision loss associated with CRAO can be restored if blood flow to the retina is restored quickly, but the American Academy of Ophthalmology asserts that there is “no conclusive evidence to support” the use of CRAO treatment after 240 minutes of blockage.

While BRVO can’t be treated, ophthalmologists often treat the leaking retinal blood vessels with these options to prevent future macula swelling and developing new blood vessel growth:

  • Laser treatment — Tiny laser burns around the macula can stop leaking fluid or diffuse laser burns in the retinal periphery to prevent abnormal blood vessel growth.
  • Anti-vascular endothelial growth factor — These injections can help reduce macula swelling and temporarily dry up abnormal new blood vessel growth.

Ready for an Appointment?

If you're experiencing signs or symptoms of retinal artery and vein occlusion, schedule an appointment or call 800-TEMPLE-MED (800-836-7536) today.

Learn more about our doctors and care team who diagnose and treat retinal artery and vein occlusion.