Behind the window of the soul, as they say, the eyes are also a window. reflection of your mental health.

“The eyes are the mirror of the brain. You can see directly the nervous system by looking at the back of the eye, towards the optic nerve and the retina,” says the ophthalmologist Dr. Christine Greer is director of medical education at the Institute for Neurodegenerative Diseases in Boca Raton, Florida.

Now scientific research is exploring whether the eyes and their examination can help diagnose Alzheimer’s disease before the first symptoms appear.

“Alzheimer’s disease begins in the brain decades before the first symptoms of memory loss appear.explains neurologist Dr. Richard Isaacson.

But how early can signs of cognitive decline appear? To find out, the scientists examined retinal tissue and the brain. 86 people with varying degrees of mental retardation.

“Our study is the first to provide a detailed analysis of the protein profiles and molecular, cellular and structural effects of Alzheimer’s disease in the human retina, as well as evidence for how they respond to changes in the brain and cognitive function,” study leader Maya said. Coronio-Hamaui, professor of neurosurgery at Cedars-Sinai in Los Angeles.

These changes in the retina associated with changes in brain regionsin the entorhinal and temporal cortex,” she adds.

The scientists collected retinal and brain tissue samples over a period of 14 years from 86 donors with Alzheimer’s disease and mild cognitive impairment – the largest number of retinal samples ever studied.

They then compared samples from donors with normal cognitive function with samples from people with mild cognitive impairment and other people with Alzheimer’s disease.

In studies where was published in February in Acta Neuropathologicaturned out to be big an increase in the number of “beta-amyloid” proteinsa key marker of the disease, in people with both Alzheimer’s disease and early cognitive decline.

microglial cells decreased by 80% in people with cognitive impairment, according to the study. These cells are responsible for protecting, repairing, and maintaining other cells, as well as removing β-amyloid from the brain and retina.

“Signs of inflammation have also been found, which may be an equally important indicator of disease progression,” notes neurologist Dr. Richard Isaacson.

“Results were also evident in people with minimal or no cognitive symptoms, suggesting that they new eye tests could help with early diagnosis“, he adds.