http://www.telegraph.co.uk/health/healt ... -eyes.html
Alzheimer's disease: it's all in the eyes
Alzheimer's disease could in future be identified by looking into the eyes of patients, new research suggests.
Published: 7:00AM BST 21 May 2010
Scientists have discovered that the dementia illness leaves tell-tale protein deposits in the eyes.
Examining eyes for evidence of the protein, which also accumulates in the brain, could provide a simple method of early diagnosis, they believe.
Confirming Alzheimer's before the disease reaches an advanced stage can have a major impact on treatment success.
The discovery emerged from a study of Down's syndrome patients, who often develop Alzheimer's symptoms by the age of 30.
Progress of the disease is accelerated in people with Down's because they have an extra copy of a key Alzheimer's gene.
Scientists found that a toxic Alzheimer's brain protein, amyloid-beta, shows up at a very early stage in the eyes of Down's patients.
The protein leads to cataracts, which were previously associated with Down's but not known to contain amyloid-beta.
The researchers, whose findings are reported in the journal Public Library of Sciences One, are now working on ways to detect tiny traces of the deposits in the eyes of ordinary patients.
Study leader Dr Lee Goldstein, from Boston University School of Medicine in the US, said: ''We are developing an eye scanner to measure amyloid-beta in the lens.
''This approach may provide a way for early detection and monitoring of related pathology in the brain.
''Effective treatments for the brain disease in Down syndrome and Alzheimer's disease are on the horizon and early detection is the key to successful intervention.''
Co-author Dr Juliet Moncaster, also from Boston University, said: ''The lens provides a window to the brain. The lens can't clear protein deposits the way the brain does. Our findings show that the same amyloid-beta protein that aggregates in the brain also accumulates in the lens and leads to these unusual cataracts in Down syndrome.''
The examinations were carried out on eyes from dead patients, leaving a question mark over the extent to which the same pattern occurs in living individuals.
An estimated 820,000 people in the UK suffer from dementia, most of whom have Alzheimer's.
Rebecca Wood, chief executive of the Alzheimer's Research Trust, said: ''These new findings add to recent studies which suggest that examining the eye for deposits of the toxic amyloid protein could one day play a part in diagnosing Alzheimer's. We desperately need to develop swift and effective means of spotting Alzheimer's early to allow future treatments to be given when most beneficial and to provide people with the chance to prepare for the future.''
Dr Susanne Sorensen, head of research for the Alzheimer's Society, said: ''This study is the first of its kind to link specific cataracts found in the eyes of people with Down's syndrome with changes in the brain associated with Alzheimer's disease. Studies like this one offer hope for finding new ways of detecting Alzheimer's disease before symptoms become apparent.
''This could help with developing treatments such as vaccines to help transform people's lives.''
Dr Steve Gentleman, reader in experimental neuropathology at Imperial College London, said the findings could pave the way to screening people in their 40s for Alzheimer's.
But he added: ''Before this could be useful we would need to know what proportion of people who die with Alzheimer's actually have these distinctive cataracts.''