Health problems with the eye significantly raise the risk of dementia, a study shows.
Patients with deteriorating vision are more likely to end up with an impaired ability to remember, think or make decisions, researchers said.
They analysed data on 12,364 adults aged 55 to 73 and found the risk of dementia was 26 per cent higher in those with age-related macular degeneration.
The researchers, from the Guangdong Academy of Medical Sciences in China, said they could not establish reasons for the links
The equivalent figure was 11 per cent for cataract sufferers and 61 per cent for those with diabetes-related eye disease.
The researchers, from the Guangdong Academy of Medical Sciences in China, said they could not establish reasons for the links.
However it could be that eye conditions are associated with well-known risk factors for dementia such as heart disease.
The results also revealed those who suffered from diabetes, heart disease, stroke and depression – known as systemic diseases – were at an increased risk of dementia.
The risk was even higher if people also had issues with their eyes – also known as an ophthalmic condition.
The researchers said: ‘Age-related macular degeneration, cataract and diabetes-related eye disease – but not glaucoma – are associated with an increased risk of dementia.
‘Individuals with both ophthalmic and systemic conditions are at higher risk of dementia compared with those with an ophthalmic or systemic condition only.’
The authors said their study was observational, and so they cannot establish reasons why having an eye condition is linked to a heightened risk of dementia.
However it could be that eye conditions are associated with well-known risk factors for dementia including diabetes, heart disease, stroke, high blood pressure and depression.
The risk was even higher if people also had issues with their eyes – also known as an ophthalmic condition
The deterioration of sight may also result in less activity within certain parts of the brain, may make people less able to recognise the faces of friends and family, and may mean they are unable to be as independent.
In the UK, cataracts affect around half of people over the age of 65, while nearly 40,000 people each year develop age-related macular degeneration.
The study was published in the British Journal of Ophthalmology.
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