by People with untreated visual impairments were significantly more likely to develop dementia, according to a new study.
Previous studies have shown a link between cognitive and visual health. However, this latest study was unique in the rigor with which vision was assessed and in how representative the sample was, said clinician scientist Dr. Joshua Ehrlich, the lead author of the report published Thursday in the journal JAMA Ophthalmology.
Ehrlich and his coauthors looked at data from the 2021 National Health and Aging Trends Study in the United States and included nearly 3,000 people.
The NHATS interviewers gave individuals in the 2021 study tablet devices with tests for near and far vision and contrast sensitivity, he said.
“We’ve done all the research to make sure the iPad tests are, in fact, equivalent to (the) gold standard test in the doctor’s office, and we’ve implemented this in the homes of thousands of older adults,” says Ehrlich, an assistant professor of ophthalmology and visual sciences at the University of Michigan in Ann Arbor.
The participants, all of whom were over the age of 71, were then screened for dementia using the Dementia Screening Interview, the study said.
Of all persons involved in the study, 12.3% showed signs of dementia. For people with distant visual transmission, that rose to 19.5%; 21.5% for near vision impairment; and 32.9% for people with moderate to severe visual impairment or who were blind, according to the study.
The study showed that even mild visual impairment can increase risk, said Dr. Arielle Silverman, director of research at the American Foundation for the Blind. Silverman was not involved in the investigation.
And the increase for moderate and severe disabilities was significant.
“The potential to increase your risk by two and a half times as a result of having a visual impairment is quite high,” says Dr. Thomas Holland, a physician-scientist at the Rush Institute for Healthy Aging and an instructor of internal medicine at Rush Medical College in Chicago. . Holland was not involved in the investigation.
Which came first?
It’s important to note that because of the way this study was designed, the research team can’t be sure that the visual impairment caused the dementia, only that they were correlated.
Dementia can cause the vision loss, or they can just happen at the same time, Ehrlich said.
There is a similar correlation between hearing loss and dementia, he added. It could be that the impairments reduce input from our senses, leading to some confusion that can accelerate cognitive decline, Holland said.
“If you can’t feel something and know you’re hurting yourself, you’re going to get hurt. That’s just the name of the game. And then the same when it comes to your hearing and your vision,” he added.
Another factor that could lead to the correlation is a potential decrease in opportunity and community participation that may come with vision loss, Silverman said.
The next steps
What should you do about it? Stay on top of eye care, Ehrlich said.
In addition to a healthy lifestyle, annual visits and visual checks are important, Holland added.
And if a problem is found, make sure it gets fixed, Ehrlich said.
“When it comes to low vision and blindness, it is estimated that more than 80 percent is preventable or even reversible,” he added.
After an exam, your eye doctor may recommend a corrective procedure, such as LASIK or cataract surgery, or it could be as simple as wearing prescription glasses, Holland said.
When it comes to dementia, preventive measures are important, and taking care of your senses is an easy way to take care of your cognition, Ehrlich said.
“The sooner the better,” Holland said. “If you notice your eyesight starting to decline, get it checked out.”
But not every case of vision loss is treatable. That’s why it’s important to link visual preventive health with rehabilitation services “so that people who become blind or have low vision can continue to actively live their lives with choice, independence and confidence,” Silverman said.
That could mean developing skills so that people who are blind can continue to move independently and safely through the world, engage in hobbies and do other things that are critical to cognitive health, she added.
“Aging is hard, but vision is something we have a lot of support for,” Silverman said. “If your vision cannot be corrected, seek a referral to a vision rehabilitation therapist for strategies to work with the vision you have, and non-visual techniques to stay engaged in all aspects of your life.”
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