Visual Impairment and Dementia Risk

These factors are:

• Quality of education in early life
• Social isolation
• Air pollution
• Traumatic brain injury
• Hearing loss
• Depression
• High blood pressure
• Diabetes
• Obesity
• Physical inactivity
• Smoking
• Excessive alcohol consumption
• Uncorrected vision loss
• High cholesterol

in the report, comprised by 27 world leading experts on dementia, they calculate that if as a society and as individuals we could completely address these 14 health and lifestyle factors it could prevent or delay nearly half (45%) of dementia cases. Of those, around two in every 100 dementia cases have been linked to visual impairment in later life.

In the updated report, researchers have concluded that there is now enough evidence to include two additional risk factors: uncorrected vision loss and high cholesterol. Together, these are associated with 9% of all dementia cases. More than one in 10 people over the age of 50 have uncorrected visual impairment. This means problems with sight that haven’t been corrected by wearing glasses, lenses or having surgery or treatment.

Uncorrected Vision Loss encompasses a variety of issues, such as not wearing glasses for short- or long-sightedness for an extended period. Notably, research has shown an increased risk of dementia in individuals with untreated diabetic retinopathy and cataracts, two conditions known to cause vision loss. Further research is necessary to fully understand the reasons behind this heightened risk, but it is known that these eye conditions are associated with inflammation and blood vessel damage, which are contributing factors to diseases like Alzheimer’s. Glaucoma and age-related macular degeneration do not appear to be linked to dementia.

How does visual impairment affect dementia risk?

Research is ongoing to unravel the relationship between visual impairment and increased dementia risk. At the moment there are three possible theories as to why the relationship exist. It’s important to note these could all be true in different people.

• Illnesses such as diabetes, which can lead to visual impairment, may also elevate the risk of dementia.
• Visual impairment can make our brain less resilient to damage. It’s important to keep our brains stimulated throughout our lives to maintain and build our cognitive reserve. Damage to our senses results in our brains receiving less stimulation and this can make us more vulnerable to diseases like Alzheimer’s.
• Biological alterations in the brain associated with conditions such as Alzheimer’s disease can also lead to changes in the eye, resulting in visual impairments.

For more information, you can visit Alzheimer’s Research UK website by clicking HERE or contacting your local GP.

Information in this article taken from Alzheimer’s Research UK website, July 2024.