While most people think of a stroke as affecting the brain, it can also affect the eye. Sudden, painless vision loss can be an eye stroke called central retinal artery
occlusion, and the American Heart Association wants to spread the word about it.

If a person suddenly, immediately loses vision in the eye, and it is painless, they should seek immediate emergency medical care, said Dr. Brian C. Mac Grory, an assistant professor of neurology and staff neurologist at the Duke Comprehensive Stroke Center at Duke University School of Medicine in Durham, N.C., and chair of the statement writing committee.

WHAT IT IS
Since there are no other symptoms than sudden, painless vision loss, this condition is difficult to diagnose, Mac Grory said. “Central retinal artery occlusion is a
cardiovascular problem disguised as an eye problem. It is less common than stroke affecting the brain but is a critical sign of ill health and requires immediate medical attention,” he said.

The retina is the layer of nerve cells lining the back wall inside the eye. “It is a small extension of the brain that lies at the back of the eye,” Mac Grory said.
A central retinal artery occlusion is a rare form of acute ischemic stroke that occurs when the one of the vessels that carries blood to your eye’s retina gets blocked by a clot, which may be composed of platelets, red blood cells, calcium, cholesterol or some combination of these, Mac Grory said.

It is a warning sign of other vascular issues, so ongoing follow-up is critical to prevent a future stroke or heart attack, Mac Grory said. When this type of eye stroke occurs, fewer than 20% of people regain functional vision in the affected eye.

MAY SIGNAL OTHER ISSUES
After experts in fields including cardiology, ophthalmology and neurology summarized the current knowledge base on the management of central retinal artery
occlusion, the American Heart Association issued a statement that these eye strokes can be a warning sign of other vascular issues.

This type of stroke can be caused by problems with carotid arteries, the blood vessels in the neck, but it may also be caused by problems with the heart, such
as atrial fibrillation, which is the most common irregular heart rhythm. The risk of having an eye stroke increases with age and in the presence of cardiovascular risk factors such as high blood pressure, high cholesterol, type 2 diabetes, smoking and obesity.

TREATMENT DISCREPANCIES
Due to a lack of large clinical trials, much uncertainty exists within the medical community about what causes eye strokes and how best to treat them, according
to the American Heart Association. As a result, there is wide range of diagnosis and treatment methods.

Since many physicians may not recognize central retinal artery occlusion as a form of stroke, testing and treatment may be delayed and take place in an
outpatient clinic instead of the emergency department, Mac Grory said. Eye strokes are a medical emergency that deserve more attention, early recognition
and immediate, emergency medical treatment, he said.

“There is a narrow time window for effective treatment of CRAO and a high rate of serious related illness. So, if a person is diagnosed in a doctor’s office
or other outpatient clinic, they should be immediately sent to a hospital emergency department for further evaluation and treatment,” Mac Grory said.
Because of the risk for future strokes or even heart attacks, people who suffer from an eye stroke need urgent screening and treatment of vascular risk factors,
which include high blood pressure, high cholesterol, diabetes and smoking, Mac Grory said.