Going for an eye test at the opticians could spot if you are at risk of dementia, breakthrough research has found.
People who have thin retinas perform worse on tests of their memory and are more likely to experience a decline in brain power.
On the back of the landmark trial, other scientists found changes in retinal thickness can even be used to predict dementia eight years later.
Experts hope targeting patients with thin retinas with drugs and lifestyle changes could prevent the onslaught of them losing their memory.
The largest trial of its kind used data from 32,000 people who had undergone the eye test, available at NHS opticians.
People who have thin retinas perform worse on tests of their memory and are more likely to experience a decline in brain power
Professor Paul Foster, who co-led the main study, said: ‘We now know we need to find people at the earliest stages before the brain is irreparably damaged.
‘The hope is that either a drug or lifestyle advice can stop this.
‘The combination of the two studies showing the increased risk I think does put it beyond doubt.
‘There is unquestionably a link between changes in the retina and changes in people’s mental state.’
Researchers at University College London and Moorfields Eye Hospital conducted the study on participants aged between 40 and 69.
They looked at the results of OCT scans, which measure the thickness of a layer of neurons on the retina – a layer at the back of the eyeball.
At the same time, participants had also undergone a series of basic cognitive tests which assessed memory, reaction time and reasoning.
The OCT and cognitive tests were then repeated in some participants around three years later, to measure any changes.
The study, published in JAMA Neurology, found a huge link between the thickness of the retinal nerve fibre layer (RNFL) and cognitive function.
And people with a thinner RNFL had almost double the risk of having mild cognitive problems – such as forgetting the number of their local takeaway.
And those people with a thinner RNFL were twice as likely to suffer cognitive decline over the next three years, the British researchers found.
The second study, also published in JAMA Neurology, backed up the findings and examined the link in more depth.
Researchers at the Erasmus Medical Centre in Rotterdam followed around 5,000 people with an average age of 69, The Mirror reports.
They discovered those with a thin retina, according to the OCT scan, were 44 per cent more likely to develop dementia over eight years.
Professor Foster and his colleagues now hope to discover the exact thickness of retinas that can lead to a diagnosis of pre-dementia,.
Professor Foster added: ‘It is well known there are significant degenerative changes in the retina and optic nerves in established dementia.
‘In carrying out this study our primary motivation was to determine if the RNFL and cognition relationship held true in the very earliest stages of cognitive decline.
‘Our findings undoubtedly suggest that the retinal abnormalities, identifiable in established dementia, begin to manifest in the early stages of cognitive decline.’
WHAT IS DEMENTIA? THE KILLER DISEASE THAT ROBS SUFFERERS OF THEIR MEMORIES
Dementia is an umbrella term used to describe a range of neurological disorders
A GLOBAL CONCERN
Dementia is an umbrella term used to describe a range of progressive neurological disorders, that is, conditions affecting the brain.
There are many different types of dementia, of which Alzheimer’s disease is the most common.
Some people may have a combination of types of dementia.
Regardless of which type is diagnosed, each person will experience their dementia in their own unique way.
Dementia is a global concern but it is most often seen in wealthier countries, where people are likely to live into very old age.
HOW MANY PEOPLE ARE AFFECTED?
The Alzheimer’s Society reports there are more than 850,000 people living with dementia in the UK today, of which more than 500,000 have Alzheimer’s.
It is estimated that the number of people living with dementia in the UK by 2025 will rise to over 1 million.
In the US, it’s estimated there are 5.5 million Alzheimer’s sufferers. A similar percentage rise is expected in the coming years.
As a person’s age increases, so does the risk of them developing dementia.
Rates of diagnosis are improving but many people with dementia are thought to still be undiagnosed.
IS THERE A CURE?
Currently there is no cure for dementia.
But new drugs can slow down its progression and the earlier it is spotted the more effective treatments are.
Source: Dementia UK