Could an eye scan be used to diagnose Alzheimer's disease?
A Toronto clinic is first in the world to test retina scans that may be able to diagnose Alzheimer's disease using a hypersensitive device developed in Canada.
Dr. Sharon Cohen, medical director at the Toronto Memory Program, says that PET scans are the gold standard for diagnosing Alzheimer's disease. The scans detect the buildup of amyloid, a type of protein associated with the degeneration of the brain in Alzheimer's.
Other diagnostic tools used include spinal taps, which test the fluid that flows between the spine and brain.
But spinal taps are very invasive. PET scans are very costly, says Cohen, and are not available in many parts of the world. There is also exposure to radiation involved in the procedure.
"The holy grail would be a blood test or retinal scan," she says, explaining why her clinic is testing the retina scans designed by Toronto firm RetiSpec.
The basic equipment is like that you would find in any optometrist's office, but RetiSpec has created a supersensitive additional camera that can detect the harmful amyloid proteins as it takes a snapshot of the back of the eye.
RetSpec CEO Eliav Shaked says regular retinal scans are used to detect structural changes in the retina.
"But what we are providing here is an incredible amount of data to allow us to really identify biomarkers for Alzheimer's,” Shaked said.
The images are created in a matter of minutes. They are then analyzed by computer to see if amyloids are present.
For Toronto resident Richard Low, the speed and ease of this process is especially appealing because he suffers from claustrophia.
He began suffering from mild symptoms of Alzheimer's a couple of years ago and has an extensive family history of the disease.
He's already been through three PET scans as part of his treatment; he had to take medication just to make it through the scans. But he would love to see something like the retina scan used instead.
"I think that this is the way to go" says Low.
The Toronto Memory Program is looking for 100 people who, like Low, have already had PET scans or spinal taps to detect amyloid in their brains. The volunteers would undergo the RetiSpec scan and the results would be compared to their previous test results.
"If the accuracy is high, then the next step would be to move to the regulators, to Health Canada and say let’s commercialize this," says Cohen.
They hope to complete this phase of the trial by the end of 2019.