Millions of people diagnosed with three common eye conditions may face a higher risk of Alzheimer’s, researchers fear.
Patients battling age-related macular degeneration, the leading cause of blindness globally, face 50 per cent higher odds of Alzheimer’s.
Those struck down with either glaucoma or diabetic retinopathy also have a similar risk, a new study suggests.
Scientists now accept eye problems could be an early warning sign of Alzheimer’s, the most common form of dementia.
More than 550,000 people in the UK and 5.5 million in the US are estimated to have the memory-robbing disorder.
But as well as being notoriously difficult to treat, the incurable disorder is tricky to diagnose, particularly in the early stages, when it is easier to combat.
Patients battling age-related macular degeneration, the leading cause of blindness, face 50 per cent higher odds of Alzheimer’s
The new findings, led by the University of Washington, could spot those who face a higher risk of Alzheimer’s much earlier on.
This would allow doctors to dish out drugs sooner, to reduce symptoms and slow down the worsening progress of the disorder.
The study adds to an array of evidence that dementia could be spotted by delving into the window of the brain, as the eye is sometimes called.
Researchers analysed data from 3,800 participants, who were all aged 65 or older – when the risk of Alzheimer’s is deemed highest.
They wanted to discover if solid proof exists to link several conditions, including cataracts, to a higher risk of the neurological disorder.
And the five-year study revealed those battling age-related macular degeneration, glaucoma and diabetic retinopathy do face higher odds.
However, cataracts – a condition that makes eyes cloudy, which is believed to strike 35 per cent of over-65s – was not an Alzheimer’s disease risk factor.
Figures estimate there are 600,000 patients with AMD, 500,000 with glaucoma and 1.5 million with diabetic retinopathy in the UK.
But the rates of the three conditions are significantly higher in the US, with two million AMD patients, 2.7 million with glaucoma and seven million with DR.
Lead author Dr Cecilia Lee remained adamant that patients diagnosed with one of the three eye conditions are not destined to develop dementia.
But she today urged specialist eye doctors to become ‘more aware’ of the risks of Alzheimer’s for those battling the conditions.
Dr Lee said: ‘Doctors seeing patients with these eye conditions might be more careful on checking on possible dementia or memory loss.’
Dr Paul Crane, study co-author, said: ‘This study solidifies that there are mechanistic things we can learn from the brain by looking at the eye.’
It comes after breakthrough research last month found going for an eye test at the opticians could spot those at risk of dementia.
People who have thin retinas perform worse on tests of their memory and are more likely to experience a decline in brain power, it found.
British researchers warned of an ‘unquestionable’ link between changes in the retina and changes in people’s mental state.
Eye doctors today called for further scientific trials that are bigger to understand the links between eye health and dementia further.
The latest findings were published today in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.
A team of researchers from the Kaiser Permanente Washington Health Institute were also involved in the study.
None of the participants had been diagnosed with Alzheimer’s at the beginning of the study – but 792 cases were flagged up by the end.