By LEE BOWMAN
Scripps Howard News Service
October 11, 2005
In a study of more than 3,600 Australians age 49 and older, researchers found that those with damage to eye blood vessels were 70 percent more likely to have a stroke during a follow-up period than those who did not have such damage.
The results held true even when the scientists took into account traditional stroke-risk factors such as smoking and high blood pressure, the researchers reported in the journal Neurology.
"The blood vessels in the eye share similar anatomical characteristics and other characteristics with the blood vessels in the brain," said Dr. Paul Mitchell of the University of Sydney, lead author of the study, which used photographs of the retina to detect the small blood-vessel changes.
The researchers followed participants for seven years, noting which ones had strokes or transient ischemic attacks, or mini-strokes, caused by blocked blood vessels.
Each year, more than 700,000 Americans experience strokes as a result of a clot blocking key blood vessels. Such clots cause more than 80 percent of all strokes. Nearly 25 percent of those who recover from their first stroke will have another brain attack within five years.
"More research needs to be done to confirm these results, but it's exciting to think that this fairly simple procedure could help us predict whether someone will be more likely to have a stroke several years later," Mitchell added.
The signs of damage included tiny bulges in blood vessels, called microaneurysms, and hemorrhages, tiny blood spots where the bulging vessels have leaked into surrounding eye tissue, but usually don't affect eyesight in the short run.
The risk was higher for those who had small blood-vessel damage in the eye, but did not have severe high blood pressure. They were 2.7 times more likely to have a stroke than those without any eye damage.
The risk of stroke was also higher in patients who had more than one type of blood-vessel damage in the eye. This type of eye damage can also be caused by diabetes. For that reason, the researchers did not include participants with diabetes in that risk analysis. Diabetes is also a risk factor for stroke.
Dr. Robert Cykiert, an ophthalmologist at New York University Medical Center in New York who was not involved in the study, agreed that the eyes are an observation window to what may be happening to blood vessels in the brain and heart.
"We've known for many years that the blood vessels in the retina can indicate if someone has high blood pressure or high cholesterol, because they're a snapshot of what is going on in the rest of the body. This seems to be the first formal study to prove that our suspicions are correct," Cykiert said, adding that he routinely reports bad blood vessels in the retina to his patients' internists.
Among the warning signs of stroke:
- Sudden numbness or weakness in the face, arm or leg, especially on one side of the body.
- Sudden confusion, trouble speaking or understanding spoken words.
- Sudden trouble seeing in one or both eyes.
- Sudden trouble walking, dizziness, loss of balance or coordination.
- Sudden severe headache with no known cause.
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