Researchers say the damage in the eye may indicate that these patients also have vascular disease in the brain.
Damage to the retina is called retinopathy. In the study, the damage was mild enough to not cause significant symptoms.
"Problems with the tiny blood vessels in the eye may be a sign that there are also problems with the blood vessels in the brain that can lead to cognitive problems," said study author Mary Haan, DrPH, MPH, of the University of California, San Francisco. "This could be very useful if a simple eye screening could give us an early indication that people might be at risk of problems with their brain health and functioning."
The study involved 511 women with an average age of 69. The women took tests of their thinking and memory skills every year for up to 10 years. Their eye health was tested about four years into the study and scans were taken of their brains about eight years into the study.
A total of 39 women, or 7.6 percent, had retinopathy. The women with retinopathy on average had lower scores on the cognitive tests than the women who did not have retinopathy. The women with retinopathy also had more areas of small vascular damage within the brain, with 47 percent larger volumes of areas of damage than women who did not have retinopathy.
The results remained the same even after adjusting for high blood pressure and diabetes, which can be a factor in vascular issues in the eye and the brain.
The study was supported by the National Heart, Lung and Blood Institute, the U.S. Department of Health and Human Services, Wyeth Pharmaceuticals and the National Institute on Aging.