Surgery to remove cataracts, which cause the eye’s clear lens to become cloudy, can restore vision instantaneously. In addition, new research suggests cataract surgery may have another benefit: reduced risk for Alzheimer’s disease and other forms of dementia.
During a recent study, scientists looked at 3,038 men and women with cataracts who were 65 or older and free of dementia at the time of their diagnosis. 1,382 had cataract surgery from this study, and the rest did not. All participants were part of a decade-long memory study that followed these participants.
Through this study, researchers found that the overall risk for dementia was 29% lower in those participants who had cataract surgery than those who did not.
Through the study, scientists looked at glaucoma surgery, another eye operation that does not restore vision but can help prevent vision loss and found no effect on dementia risk.
The findings in this study suggest that vision loss and hearing loss are important risk factors for cognitive decline. People who have trouble seeing or hearing may withdraw from activities like exercise, social interactions, reading, or intellectual pursuits, all of which are tied to a lower risk of dementia.
In addition, scientists also suggested a possible physiological mechanism. The visual cortex changes with vision loss and impaired vision may lessen input to the brain, leading to brain shrinkage, also a risk factor for dementia. A prior study found an increase in the brain’s gray matter volume after cataract surgery.
Currently, the exact mechanism for the benefits of cataract surgery is still unknown. However, as future studies continue, cataract surgery may have clinical relevance in older adults at risk for developing dementia.