A vision test could predict Alzheimer's disease

Tampa – Advances in ophthalmic research technology can help physicians one day diagnose people with Alzheimer's disease long before the symptoms appear, researchers said on Thursday.

Using equipment similar to those already available in most ophthalmic offices, the researchers discovered signs of Alzheimer's in a small sample of 30 people, according to a study published in the Journal of the American Medical Association (JAMA) Opthalmology.

Those who participated in the study, all of them mid-1970s without visible symptoms of Alzheimer's disease, underwent PET scans or spinal fluid analysis.

About half of them had elevated levels of amyloid or tau, the Alzheimer's, suggesting that they may eventually develop dementia.

In this group, the researchers also saw thinning of the retina, something that experts had seen earlier in autopsies of people who died of Alzheimer's disease.

"In patients with a high amyloid or tau level, we discovered a significant thinning in the middle of the retina," says Rajendra Apte, one of the researchers and professor of Ophthalmology and visual sciences at the University of Washington in St. Louis.

"We all have a small area without blood vessels in the center of our retina, which is responsible for our more accurate vision." We discovered that this area without blood vessels was significantly expanded in people with preclinical Alzheimer's, "said the specialist.

However, the study did not show whether participants with thinner retinas developed Alzheimer's or not.

That is why Doug Brown, policy director and research at the American Alzheimer's Society, called the research area "fascinating", but he was cautious.

"Without confirming that one of the people with preclinical Alzheimer's disease has actually developed the disease, we need to have this happen over a longer period of time in a much larger group to draw firm conclusions," said Brown, who was not involved in the study. .

He met Sara Imarisio, head of research at the Alzheimer Research Center in the United Kingdom. "Although the eye tests used in this study are relatively fast, cheap and non-invasive, to the extent that only 30 people have participated in the study, we need to see more research before we can say how useful this method could be. to show the signs, initials of Alzheimer's disease, "he said.

Increase in dementia

Experts say that brain damage from Alzheimer's disease can start up to two decades before signs of memory loss appear.

Approximately 50 million people worldwide suffer from dementia, and the number is expected to increase in the coming decades as the population ages.

Alzheimer's is the most common form of dementia and can not be cured.

But earlier detection can allow interventions of medicines or habits that stop the disease.

Currently, doctors are using PET scans and lumbar punctures to help diagnose Alzheimer's disease, both costly and invasive techniques.

The type of technology used in the JAMA study is called optical coherence tomography angiography (OCT-A).

It is often used to relieve the eye so that the doctor can measure the thickness of the retina and optic nerve.

The researchers say that the retina and the central nervous system are interconnected, so changes in the brain can be reflected in the cells of the retina.

The lead author of the study, Bliss E. O & # 39; Bryhim, a physician from the Department of Ophthalmology and Visual Sciences, said: "This technique has great potential to become a screening tool to help decide who should undergo further testing • costly and invasive for Alzheimer's disease before the onset of clinical symptoms. "

The authors of the study admit that more work is needed to confirm that the technique works in larger populations, but they hope that one day it can help detect signs in people between 40 and 50 years old.

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