Researchers at Duke University used optical coherence tomography angiography (OCTA), a noninvasive imaging technique, to show that the small blood vessels in the retina at the back of the eye are altered in patients with Alzheimer’s disease.

The researchers compared the retinas of Alzheimer’s patients with those of people with mild cognitive impairment, as well as with those of healthy people. They found that the Alzheimer’s group had loss of small retinal blood vessels at the back of the eye and that a specific layer of the retina was thinner. Even people with mild cognitive impairment did not show these changes.

A team of researchers from Sheba Medical Center in Israel used OCTA to examine 400 people who had a family history of the disease but showed no symptoms themselves. They compared their retina and brain scans with those who had no family history of Alzheimer’s and found that the inner layer of the retina was thinner in people with a family history.

Because the retina is connected to the brain by way of the optic nerve, researchers believe the deterioration in the retina and its blood vessels could mirror the changes going on in the blood vessels and structures in the brain, thereby offering a window into the disease process.

The goal of the research is to find a quick, inexpensive way to detect Alzheimer’s at the earliest signs.

Results from both studies were presented at AAO 2018, Oct. 27-28 in Chicago.