May 6, 2020
Poor hearing is a known risk factor for Alzheimer’s disease and other forms of dementia. Now a new study reports that poor vision may likewise increase your risk of developing dementia. The findings underscore the importance of getting regular vision and hearing checks to help keep the brain in optimal health, by keeping individuals as functional as possible to engage in as many activities as possible.
For the study, researchers analyzed data from 1,061 women enrolled in the Women’s Health Initiative, a large and long-running study of women in their 60s, 70s and 80s. Of those, 183 had vision problems in at least one eye, resulting from a variety of eye diseases that could not be easily corrected with glasses. The researchers followed them for about four years.
The researchers found that compared to their peers with good vision, those with visual problems were at two to five times the risk of having dementia or mild cognitive impairment, a form of memory impairment that often progresses to full-blown Alzheimer’s disease. Memory problems were most pronounced in women whose vision was worse than 20/100 on eye exams (normal vision is 20/20).
The researchers, from Stanford University, speculate there may be various reasons for the higher likelihood of dementia in those with vision problems.
Poor vision, like poor hearing, is a form of sensory deprivation, in which the brain is getting only limited stimulation. Stimulation of the brain, whether it’s through the senses or through cognitively stimulating activities like learning a new language or doing crossword puzzles, has been linked to a lower risk of dementia.
Poor vision, also like poor hearing, also often results in social isolation. Older people who can’t see well may be reluctant to leave the house or drive to see friends. Regular social interactions are likewise linked to a lower risk of developing dementia.
“Regardless of mechanism — common cause, sensory deprivation, or a combination of factors — visual impairment could represent an early harbinger of risk for dementia,” the authors write. “These findings suggest potential value for vision screening and vision-improving interventions.”
Eye diseases like glaucoma, macular degeneration and diabetic retinopathy are common in older people. Regular eye exams can help to identify these problems early, and effective treatments are available for many eye problems to limit vision loss.
Although this study only looked at women, the results likely apply to men, too. The findings underscore the importance of regular eye and hearing exams to help maintain not just the health of those senses but of brain health as well.
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Marc Flajolet, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Elaine M. Tran, BA; Marcia L. Stefanick, PhD; Victor W. Henderson, MD, MS; et al: “Association of Visual Impairment With Risk of Incident Dementia in a Women’s Health Initiative Population.” JAMA Ophthalmology, April 16, 2020
