- Researchers from NeuRA found vision deterioration significantly predicted multi-domain cognitive decline.
- This research highlights the importance of regular eye tests and maintaining good vision to reduce dementia risk.
- Staying socially active could help lessen the negative effects that declining vision has on cognitive health.
Regular eye tests may help predict our risk of developing dementia, researchers from Neuroscience Research Australia (NeuRA) have found.
Dementia rates are rapidly increasing in Australia and globally, with vision problems contributing to an estimated 4.7% of the burden. NeuRA Postdoctoral Research Fellow in Cognitive Health, Dr Nikki-Anne Wilson, led the research that examined the effect of changes to eyesight in adults over a 12-year period.
"While people are encouraged to get regular eye tests, this research highlights that vision checks are important from a cognitive perspective as well," Dr Wilson said.
"It is normal for some loss of visual acuity to occur with age, which refers to how clearly objects can be seen from a distance. However, just as we are advised to get our blood pressure checked, we should also be getting our eyes checked too."
The PATH through life study examined deterioration in vision and cognitive decline over a 12-year period.
"The relationship between visual acuity and cognitive performance was evident across multiple cognitive domains," Dr Wilson said, highlighting the importance of maintaining good vision for overall cognitive health.
Vision loss a dementia risk factor
Uncorrected vision loss was recently included as one of 14 key modifiable dementia risk factors by The Lancet Commission.
"A decline in vision can be caused by a range of factors, some of which are treatable. For example, cataracts, or vision decline that can be supported with the correct glasses," Dr Wilson said.
"What the research is now showing is that identifying these changes early and addressing them may help reduce the risk of developing dementia."
How does vision contribute to dementia risk?
"We know that the protein associated with Alzheimer's disease can be found in both the brain and the retina," Dr Wilson said.
"Neuroimaging findings also indicate that visual impairment results in brain changes both within and beyond parts of the brain which process vision."
But it is important to also consider the impact that a decline in vision may have on broader psychosocial factors.
"We show for the first time that the relationship between a decline in vision and global cognitive performance may be partly explained by reduced social contact," Dr Wilson said.
"People experiencing poorer vision may be more likely to avoid social events due to anxiety and this too may impact their cognitive performance. Our findings indicate the importance of maintaining social contact, not only because social isolation is a risk factor for dementia itself but also because it might also help to reduce the impact of other risk factors, such as poorer vision. However, further work is needed."
Easy as implementing current eye tests
Past studies looking at vision and cognitive health have often relied on self-reported visual impairment, which can be unreliable.
"One of the strengths of my study is that we used the standard Snellen chart, available in every doctor's office, to measure visual acuity," Dr Wilson said.
"This easily available measure can be included as part of an overall clinical approach to supporting brain health in older adults. However, we need to ensure equitable access to treatment.
