In a new study, researchers found age-related macular degeneration, cataract and diabetes-related eye disease are linked to an increased risk of dementia.
They found vision impairment can be one of the first signs of dementia, and reduced stimulation of visual sensory pathways is believed to accelerate its progression.
Some small studies have suggested there may be a link between ophthalmic conditions that cause vision impairment—age-related macular degeneration, cataract, diabetes-related eye disease and glaucoma—and cognitive impairment.
The incidence of these ophthalmic conditions increases with age, as does the incidence of systematic conditions such as diabetes, high blood pressure, heart disease, depression and stroke, which are accepted risk factors for dementia.
In the study, the team analyzed data on 12,364 adults aged 55-73 years enrolled in the UK Biobank.
The participants were assessed between 2006 and 2010 and followed up until early 2021. During the 1,263,513 person-years of follow-up, 2,304 cases of dementia were recorded.
The team showed that age-related macular degeneration, cataract and diabetes-related eye disease, but not glaucoma, were linked to an increased risk of dementia.
Compared with people who did not have these eye conditions at the start of the study, the risk of dementia was 26% higher in those with age-related macular degeneration, 11% higher in those with cataracts, and 61% higher in those with diabetes-related eye disease.
While glaucoma was not linked to an increased risk of Alzheimer’s disease, it was linked to a higher risk of vascular dementia.
At the start of the study, participants were asked whether they had ever experienced a heart attack, angina, stroke, high blood pressure or diabetes, and were assessed for depression.
Diabetes, heart disease, stroke and depression were all associated with increased risk of dementia.
Having one of these conditions (a systemic condition) as well as an eye condition increased the risk of dementia further, and the risk was greatest when diabetes-related eye disease occurred alongside a systemic condition.
A larger relative risk for dementia was observed among individuals with more eye conditions.
The team concludes that age-related macular degeneration, cataract and diabetes-related eye disease but not glaucoma are associated with an increased risk of dementia.
Newly developed high blood pressure, diabetes, stroke, heart disease and depression mediated the association between cataract/ diabetes-related eye disease and dementia.
For more information about dementia and your health, please see recent studies about this common tooth disease may increase risks of dementia and results showing that a new way to predict future dementia, Alzheimer’s risk.
The study is published in the British Journal of Ophthalmology.
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