Evidence Mounts That an Eye Scan May Detect Early Alzheimer's Disease

Two studies presented at the 122nd Annual Meeting of the American Academy of Ophthalmology demonstrate that a new, non-invasive imaging device can spot signs of Alzheimer's in a matter of seconds, reports ScienceDaily . The optical coherence tomography angiography (OCTA) technique enables doctors to visualize the smallest veins in the back of the eye, including the red blood cells moving through the retina. Duke University researchers used OCTA to compare the retinas of persons with Alzheimer's with those of people with mild cognitive impairment, as well as healthy subjects. The Alzheimer's group exhibited loss of small retinal blood vessels at the back of the eye as well as a thinner retinal layer. Another team examined 400 people with a family history of Alzheimer's, but who were themselves asymptomatic. Their retina and brain scans were compared to those who had no family history of Alzheimer's. The inner layer of the retina was found to be thinner in people with a family history, while the brain scan showed that their hippocampus had already started to contract. Both of these factors were associated with scoring worse on a cognitive function test.