Two independent studies presented at the Alzheimer’s Association International Conference 2014 have led to the early stage development of eye tests which may aid the detection of Alzheimer’s. Both studies use fluorescent compounds to show how much of the Alzheimer’s hallmark protein amyloid has been deposited in the eye. Amyloid is found in sticky clumps in the brain in people with Alzheimer’s and the authors of these studies believe that the amount of amyloid detected in the eye test is a good indicator of how much amyloid is present in the brain. They hope that these eye tests can be used to determine whether someone is at risk of developing Alzheimer’s.
One study, by researchers at Cedars-Sinai Medical Center, used the compound curcumin, which binds strongly to the amyloid protein and produces a fluorescent signal. The researchers used their test to measure amyloid in the eye and compared it to levels of amyloid seen in the brain using a PET brain scan. They determined that the eye test gave an accurate indication of amyloid levels in the brain. The other study was conducted by the company Cognoptix, and used a fluorescent compound which can detect amyloid in the lens of the eye. The Cognoptix trial indicated that this eye test could be used as a potential diagnostic tool for Alzheimer’s.
Dr Simon Ridley, Head of Research at Alzheimer’s Research UK, the UK’s leading dementia research charity, said:
“It is difficult to diagnose Alzheimer’s disease accurately and, in many cases, by the time the symptoms have developed, damage has already been going on in the brain for a number of years. 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.
“This research is promising but is in the very early stages and involves very small sample sizes. It is too soon to determine whether these types of tests will be useful for diagnosis of dementia and we would need to see the results of larger trials before drawing any firmer conclusions.”
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