March 14, 2012 — To update the old saying, the eyes may be the windows to the brain.

A new study suggests that people with even minimal eye damage involving the blood vessels of the retina, due to vascular disease, have a higher risk for memory and thinking declines.

Researchers say problems with the blood vessels in the eyes may be an important clue that the blood vessels in the brain are not functioning properly.

If this proves to be the case, eye screening to check for damage to the blood vessels of the retina, or retinopathy, could potentially help identify people at risk for dementia.

Eye Health, Brain Health

Retinopathy is a common complication of diabetes and uncontrolled high blood pressure, and it is a leading cause of blindness among adults in the United States.

Diabetes and high blood pressure have also been linked to a higher risk for memory and thinking declines.

To find out whether retinopathy might serve as an early warning sign of vascular-related mental issues, researchers examined data from a large study known as the Women’s Health Initiative.

The analysis included just over 500 older women who underwent mental testing annually for up to 10 years to evaluate memory and thinking skills.

The women also had a single eye examination around four years after entering the study and brain scans about eight years after they were enrolled.

Overall, 39 women (7.6%) were found to have retinopathy, but their vision was not measurably worse than women without the disease.

Compared to women who did not show evidence of vessel damage to the eyes, these women had lower average scores on the memory and thinking tests. Brain scanning revealed that they also had more evidence of blood vessel damage within the brain.

Retinopathy and Memory Loss

The findings suggest that even very early retinopathy may be an indicator for small vessel disease and a risk factor for vessel-related memory and thinking declines, says researcher Mary Haan, DrPH, MPH, of the University of California, San Francisco.

She tells WebMD that larger studies with longer follow-up times will be needed to confirm the findings.

Stroke neurologist Rebecca F. Gottesman, MD, PhD, says it also remains to be seen if retinopathy screening provides clinically meaningful information about brain health.

Gottesman is an associate professor of neurology and epidemiology at Johns Hopkins University School of Medicine in Baltimore.

“Retinopathy [testing] may prove to be a useful tool for identifying people at risk for [mental] declines, but we aren’t there yet,” she tells WebMD.

The study appears in the March 14 online issue of the journal Neurology.