Doctors have learned to diagnose Alzheimer's disease in the eyes.

Scientists at the Cedars-Sinai Medical Center in Los Angeles examined the eyes and brain tissue of 86 deceased people diagnosed with cognitive impairment. During the study, it was possible to find features that allow diagnosing Alzheimer's disease in the early stages - before the appearance of obvious symptoms. The retina was found to have excessive amounts of beta-amyloid 42, a protein that forms "plaques" that accumulate in the brains of people with Alzheimer's disease. Also in the samples were cells of the nervous system called microglia - they also appear in the development of dementia.