Eyes reveal risk of stroke

Looking into our eyes may help doctors predict who is at risk for stroke. A new study found that people with changes in the small blood vessels in their eyes are more likely to later suffer a stroke than people without these signs.

The results held true even after researchers took into account traditional risk factors for stroke such as smoking and high blood pressure, according to the study published in the October 11, 2005 issue of Neurology, the scientific journal of the American Academy of Neurology.

The study involved 3,654 Australians age 49 and older. Researchers took special photographs of the retina of the eyes of the participants and examined them for changes suggestive of small blood vessel damage, or retinopathy. These small vessel changes can be seen in the early stages of the condition, well before eyesight is affected.

"The blood vessels in the eyes share similar anatomical characteristics and other characteristics with the blood vessels in the brain," said Paul Mitchell, MD, PhD, of the University of Sydney in Australia. "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."

The researchers followed the participants for seven years, tracking which participants had strokes or transient ischemic attacks, also called mini-strokes. For those who died during the study, researchers examined the cause of death to determine whether stroke was involved.

Those with eye blood vessel damage were 70 percent more likely to have a stroke during the study than those without the damage. The risk was higher in those with small vessel signs in the eye but without severe high blood pressure; they were 2.7 times more likely to have a stroke than those without eye signs. The risk was also higher for those with more than one type of blood vessel lesion. (Because diabetes can cause this type of eye damage, these results did not include participants with diabetes, which is also a risk factor for stroke.)

The signs of damage include tiny bulges in the blood vessels, or microaneurysms, and hemorrhages, or tiny blood spots where the microaneurysms leak blood.