Eye tests could help diagnose early stage dementia

Early trials of two techniques show that a key Alzheimer’s biomarker can be identified in the retina and lens of the eye.

Both methods were able to distinguish between probable Alzheimer’s patients and healthy volunteers with a high level of accuracy.

Although the research is still at an early stage, further work could see such tests used as a first step in identifying individuals with Alzheimer’s.

After an initial eye test, more expensive and costly procedures such as PET (positron emission tomography) scans or spinal fluid analysis would then be used to confirm the disease.

Early diagnosis of Alzheimer’s is essential to developing effective treatments that do more than alleviate the condition’s symptoms.

Virtually every trial of a drug designed to halt or reverse Alzheimer’s progression has ended in failure because the patients taking part have already suffered too much damage to their brains, scientists believe.

Shaun Frost, from the Australian science agency the Commonwealth Scientific and Industrial Research Organisation, who led one of the studies, said: “We envision this technology potentially as an initial screen that could complement what is currently used: brain PET imaging, MRI imaging, and clinical tests.

“If further research shows that our initial findings are correct, it could potentially be delivered as part of an individual’s regular eye check-up.”

The eye tests exploit the fact that the eye is, in effect, an extension of the brain. In both studies, scientists looked for signs of beta-amyloid protein, which forms clumps in the brains of Alzheimer’s patients and is a key hallmark of the disease.

Dr Simon Ridley, head of science at the charity Alzheimer’s Research UK, said: “The development of a quick, cheap, non-invasive test to detect Alzheimer’s would be an important step in helping people to receive an early diagnosis, and helping to improve clinical trials so that potential new treatments have the best chance of success.”