BOSTON (CBS) — They say “the eyes are the windows to the soul” and researchers at Duke University say a quick eye exam could one day identify patients at risk for Alzheimer’s disease long before symptoms begin.

When an eye doctor examines the back of your eye, they are literally looking at a part of your brain: your retina. Typically, they can see a network of tiny blood vessels but researchers identified a change that could signal early Alzheimer’s.

They looked at the retinas of 200 people using a new non-invasive technology that takes high-resolution images of the retina. They found that in people with Alzheimer’s disease the web of vessels was less dense and more sparse in certain places.

They say this loss of blood vessels may mirror what’s going on in other tiny blood vessels in the brain, even before a patient develops memory loss.

Dr. Mallika Marshall