In a major breakthrough scientists have found a genetic link between cataracts and the debilitating brain disease.
This follows previous findings that a toxic protein, which builds up in the brains of dementia patients causing confusion and memory loss also accumulates in the eyes.
Now they have found that not only are dementia and cataracts linked, but that Alzheimer’s may be triggered from outside the brain.
The revolutionary findings by the Boston University Schools of Medicine and Public Health in Massachusetts pave the way for an opticians’ eye test to detect the degenerative disease early.
At least 850,000 people in Britain suffer from dementia
Researchers, whose results are published in the online journal PLoS ONE, looked at brain scans a decade on from original eye examinations.
They concluded that there was a link between cortical cataracts – the most common form – and Alzheimer’s-related measures of brain degeneration.
They then looked at nearly 190,000 DNA sequence variations. The protein deltacatenin appeared to be particularly important and further research found increased deposits of it in lens tissue from people who had Alzheimer’s – but not from those who didn’t.
This suggests both diseases may have the same origin. Professor Lindsay Farrer, from the Boston team, said: “This study gives hope we are moving toward earlier diagnosis and new treatment targets for this debilitating disease.”
Jessica Smith, from the Alzheimer’s Society, said: “This study highlights some interesting avenues for further investigation.”
At least 850,000 people in Britain suffer from dementia.