The first signs of Alzheimer's may appear in your eyes

The first signs of Alzheimer's may appear in your eyes

Eyes are more than a window to the soul—they're also a reflection of a person's cognitive health.

A recent study has revealed how the eye can help diagnose Alzheimer's disease before symptoms begin. The disease is well advanced by the time memory and behavior are affected.

"Alzheimer's disease begins in the brain decades before the first symptoms of memory loss," said Dr. Richard Isaacson, a preventive Alzheimer's neurologist.

"If doctors are able to identify the disease in its earliest stages, people can make healthy lifestyle choices and control risk factors such as high blood pressure, high cholesterol and diabetes," Isaacson said.

The researchers collected retinal and brain tissue samples over 14 years from 86 human donors with Alzheimer's disease and mild cognitive impairment.

The researchers then compared samples from donors with normal cognitive function to those with mild cognitive impairment and those with late-stage Alzheimer's disease.

The study, published in the journal Acta Neuropathologica, found significant increases in beta-amyloid, a key marker of Alzheimer's disease, in people with Alzheimer's and those with early cognitive decline.

Microglial cells dropped by 80% in those with cognitive problems, the study found. These cells are responsible for repairing and maintaining other cells, including clearing beta-amyloid from the brain and retina.

"The findings were also evident in people with no or minimal cognitive symptoms, suggesting that these new eye tests may help with early diagnosis,"

"These findings may eventually lead to the development of imaging techniques that allow us to diagnose Alzheimer's disease earlier and monitor its progression noninvasively by looking through the eye," Isaacson said.