By age 65, most adults in the United States will develop cataracts. What’s more, these older adults face a higher risk of developing Alzheimer’s disease (AD). Interestingly, recent study findings published in JAMA Internal Medicine show that the surgical removal of cataracts significantly reduces the risk of developing Alzheimer’s, reports a press release from the University of Washington (UW) School of Medicine.
Cataracts are protein deposits that build up on the lenses of the eyes, clouding and yellowing them. The retinal condition develops slowly and is the most common cause of vision loss worldwide. Cataract symptoms include extreme sensitivity to bright light and glare, poor night vision that makes driving difficult, cloudy or blurred vision, seeing halos around lights and detecting colors as faded or yellowed.
For the investigation, researchers reviewed longitudinal data from the ongoing observational study Adult Changes in Thought (ACT), which followed over 5,000 people over 65. After assessing information about 3,000 individuals in ACT who underwent cataract surgery, researchers adjusted for potentially confounding factors, such as the fact that individuals who underwent cataract surgery might have been healthier and had a lower risk for dementia in the first place.
Seniors who underwent cataract surgery experienced an almost 30% reduced risk of developing dementia from any cause compared with those who did not have the operation, even after adjusting for the other potential reasons for the drop. Additionally, researchers noted this lowered risk lasted at least 10 years post-surgery.
“This is really exciting because no other medical intervention has shown such a strong association with lessening dementia risk in older individuals,” explained Cecilia Lee, MD, MS, an associate professor and Klorfine Family Endowed Chair in ophthalmology at the university. “Cataract surgery would improve the visual acuity, the vision, and that improves and increases the visual stimuli into the brain. So that allows the cataract surgery patients to engage with the world better and that is protective of dementia.”
A prior inquiry by Lee’s research team also showed a link between other retinal diseases, such as age-related macular degeneration, and the development of Alzheimer’s, which supports further studies on the connection between the eyes and the brain and dementia.
Interestingly, results also showed that participants assessed for a potential association between eye surgery for glaucoma and dementia did not show the same protective connection.
The study was not without limitations. Researchers said the results could be chalked up to unmeasured or residual factors found in these types of investigations, coding errors for the diagnosis of cataracts, the fact that only first cataract procedures were assessed and the fact that the population studied was mostly white.
Nevertheless, Lee advised that there are valuable takeaways from the findings for older adults who are starting to experience vision problems due to cataracts.
“I think it would be important for them to be evaluated by an ophthalmologist, not an optometrist,” she said. “Ophthalmologists are medical doctors that are trained to do eye surgeries. So they have the training and the tools to evaluate whether one is a surgical candidate for cataract surgery. And then, in fact, whether they may benefit from cataract surgery.”
To learn about vision problems in African Americans, read "Black Seniors at Risk for Some Eye Diseases; Exams Recommended."