What Is Central Retinal Artery Occlusion?

Central retinal artery occlusion, also called CRAO, happens when blood flow to the retina suddenly becomes blocked. The retina is the light-sensitive tissue in the back of the eye that helps send visual information to the brain.

Without enough blood and oxygen, the retina can become damaged very quickly. CRAO is a medical emergency that can lead to permanent vision loss if not treated right away.

CRAO is most often caused by a blood clot or cholesterol plaque blocking the retinal artery. Conditions that affect blood vessels and circulation can increase the risk, including:

• High blood pressure
• Diabetes
• High cholesterol
• Heart disease
• Smoking
• Blood clotting disorders
• Aging

Because CRAO may be linked to stroke risk, emergency medical care is important.

Symptoms

Symptoms usually begin suddenly and affect only one eye. Vision changes are typically painless but can be severe.

Common symptoms include:

• Sudden loss of vision in one eye
• Severe blurring or dimming of vision
• Partial or complete blindness in one eye

How Is It Diagnosed?

Providers diagnose CRAO with a detailed eye exam and tests that evaluate blood flow to the retina. Your eye may be dilated so the retina can be examined more closely.

Additional testing may include retinal imaging, blood work, heart evaluation, and studies of the blood vessels in the neck. These tests help identify the cause of the blockage and check for related health concerns.

How Is It Treated?

CRAO requires immediate medical attention. Treatment is aimed at restoring blood flow and protecting the retina from further damage.

Emergency treatments may include lowering pressure inside the eye, eye massage, or oxygen-based therapies such as hyperbaric oxygen treatment in selected cases. Some patients may also need medications or additional testing to reduce the risk of stroke or future blood vessel problems.

Even with treatment, vision recovery may be limited. Early care offers the best chance of preserving eyesight.