A new study suggests cataract surgery may be associated with a significantly lower risk of developing dementia among older adults.
Cataracts cloud the lens of the eye, causing vision to become blurry or less colorful. Most develop slowly over time and affect people later in life. Surgery to treat the condition involves removing the lens of the eye and replacing it with a clear artificial lens, a procedure that is relatively simple and common.
Researchers from the University of Washington School of Medicine in Seattle analyzed data gathered as part of a years-long observational study including more than 5,000 participants 65 and older designed to observe the development of dementia.
The study included data from more than 3,000 dementia-free participants with cataracts or glaucoma. Researchers followed up with participants every two years and noted when dementia symptoms or Alzheimer’s disease presented themselves. Of the 3,038 participants, 853 developed dementia, including 709 with Alzheimer’s disease.
After analyzing the data, researchers found that participants who underwent cataract surgery had nearly 30 percent lower risk of developing dementia compared with those who did not have the procedure. The study also found that the reduction of risk continued for at least a decade following surgery and was associated specifically with the lower risk of Alzheimer’s.
“This is really exciting because no other medical intervention has shown such a strong association with lessening dementia risk in older individuals,” Cecilia S. Lee, ophthalmologist and the study’s lead author, said in a statement.
While the study did not directly link cataract surgery to a lessened dementia risk, researchers hypothesize that the lower risk may be associated with higher quality sensory input from the eyes to the brain after cataract surgery.
Lee said those who have their cataracts removed are also getting more blue light.
“Some special cells in the retina are associated with cognition and regulate sleep cycles, and these cells respond well to blue light,” Lee said. “Cataracts specifically block blue light, and cataract surgery could reactivate those cells.”
The research was published in the journal JAMA Internal Medicine.
More than 6 million Americans are living with Alzheimer’s and the Centers for Disease Control and Prevention (CDC) estimates that number will increase to 14 million by 2060.
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