Eye Health as a Window to Dementia Risk
Dementia prevention often focuses on brain-stimulating activities and stress reduction, but eye health is a surprising yet critical factor. Dr. Benjamin Bert, a board-certified ophthalmologist at MemorialCare Orange Coast Medical Center, explains, “The eye can provide a window to the health of the brain and other parts of the body.” Research shows that untreated vision loss is a major modifiable risk factor for dementia, and correcting visual deficits can significantly lower risk.
The Bidirectional Link Between Vision and Dementia
Dr. Andrew Lee, chair of ophthalmology at Houston Methodist, notes, “Vision loss and dementia are closely intertwined co-morbidities.” The Lancet Commission on dementia prevention lists untreated vision loss as a major modifiable risk factor, and 1 in 5 dementia cases may be partially attributable to visual impairment. Studies, including a Rutgers University study, found that participants with cognitive impairment have more microvessel abnormalities in the eye. Research from Houston Methodist also suggests that early indicators of Alzheimer's disease appear as stress in the peripheral retina.
How Correcting Vision Reduces Dementia Risk
Correcting visual deficits helps maintain brain stimulation. Dr. Bert says, “Studies have not shown a direct correlation that poor vision leads to dementia, but it certainly increases the risk.” This is because correcting vision allows continued interaction with the visual world, stimulating the brain. Dr. Lee adds that vision issues deprive the brain's visual pathways of necessary stimulation, causing faster deterioration from dementia. Eye exams can assess vision, contrast sensitivity, and retinal blood vessels, providing insight into dementia risk. For example, cataract surgery or age-related macular degeneration treatment can reduce dementia risk by up to 30%.
Protecting Eye Health to Lower Dementia Risk
Simple steps can protect eye health and reduce dementia risk. Dr. Bert recommends updating corrective lenses or having surgery for cataracts, glaucoma, or macular degeneration to maximize remaining vision. Regular eye exams are crucial, as subtle changes in visual sensitivity or retinal blood vessel damage can appear up to a decade before dementia symptoms. General tips include not sleeping in contact lenses, limiting screen time, getting regular exams, not ignoring vision changes, removing makeup at night, avoiding sun staring, using proper contact lens solution, and not smoking.
Eye Health After a Dementia Diagnosis
Even after a dementia diagnosis, maintaining eye health is vital. Dr. Bert explains, “Ensuring that they have the best vision can allow for them to be able to have the best visual sensory input to allow their brain to work as well as it can.” Untreated vision loss amplifies confusion and spatial awareness issues. Dr. Lee notes that providing proper eyeglasses or surgery helps patients navigate safely, reduce fall risk, and maintain cognitive fitness. Additionally, ocular coherence tomography (OCT), a noninvasive eye exam, can track dementia progression and potentially enable earlier diagnosis.
