A simple eye test could determine if a person is likely to develop Alzheimer’s disease decades before they show symptoms, a leading US medical scientist says.

Professor Peter Snyder, a neuroscientist from Brown University and Rhode Island Hospital in the US, said the presence of retinal plaque on a person’s eyes could be a precursor to determine whether someone will develop the disease.

He is visiting the Gold Coast campus of Queensland’s Griffith University and will present his findings to a conference at the weekend.

He said early research had been promising, but a diagnostic technology was still several years away.

Alzheimer’s disease usually occurs after the age of 65. Photo: Getty

“What I’m looking for are tiny, tiny inclusion bodies or plaques in the retina that seem to correlate with the amount of amyloid protein built up in the brain,” Professor Snyder said.

“By the time someone has symptoms, if the disease has been creeping up in the brain for 20 or 30 years, by the time they are showing symptoms, it may already be too late.

“It’s very hard to save tissue that is already dead or dying, so I want to identify people early so that we can develop effective therapies.”

Professor Snyder’s research included testing 80 people with an average age of 61, and giving them brain scans.

Of those people, 20 had a build up of amyloid protein in the brain, which was already a confirmed identifier of Alzheimer’s disease, and almost all of those 20 people had signs of retinal plaque.

I do worry about people finding out early.
Professor Snyder

Professor Snyder said he understood some people might not want to know if they were likely to develop Alzheimer’s.

“These people [who test positive] are still ostensibly healthy,” he said.

“They’re raising families and sending kids off to college and going to work and I do worry about this.

“It really is a chicken and egg issue, but I honestly believe that if we don’t try to test drugs, therapies that might be effective in people in the earliest stages of the disease we’re never going to find something that slows progression of the disease.”

He said he found that once people released they were at an increased risk, they looked after themselves better, but people who were found not at risk, did not.

“There’s an amazing thing that happens — they start to take better care of themselves, they start to eat a healthier diet, they start to exercise more, they start to improve their sleep habits.

“And the funny thing is the people who know they’re low risk, do none of those things to improve their health, so there may actually be a silver lining to this.”

– ABC