Cataract surgery may lower dementia risk

The study’s authors believe the heightened sensory input and increased exposure to blue light after cataract surgery may help explain why. There is hope that this information might lead to potential new therapies to either slow down or prevent age-related dementia.

The results from this observational study appear in the journal JAMA Internal MedicineTrusted Source.

What are cataracts? 

A cataract occurs when proteins in the naturally clear lens of the eye break down, causing it to become “cloudy.”

Vision becomes foggy, and objects may appear blurry or less colorful. Cataracts generally start small, but over time if left untreated, they can grow and impair vision, making it difficult to read and drive.

An estimated 94 millionTrusted Source people, globally, have cataracts.

Aging is the most common cause of cataracts. Certain risk factors, including smoking, diabetes, excessive sun exposure throughout a lifetime, and previous eye injuries, can increase the risk of developing cataracts.

The only way to remove a cataract is through cataract surgery. The procedure involves an eye surgeon removing the eye’s natural lens and replacing it with an artificial lens called an intraocular lens (IOL).

The aging eye and the aging brain

Medical News Today spoke with lead researcher Dr. Cecilia S. Lee, associate professor and Klorfine Family Endowed Chair in ophthalmology at the University of Washington School of Medicine.

She explained that previous research has found an association between several eye diseases, such as age-related macular degeneration (AMD) and diabetic retinopathy, and an increased riskTrusted Source of Alzheimer’s disease and dementia.

“A cataract is a natural aging process of the eye and affects the majority of older adults who are at risk for dementia,” Dr. Lee explained.

“Sensory loss, including vision and hearing, is of interest to the research community as a possible modifiable risk factor for dementia. Because cataract surgery improves visual function, we hypothesized that older people who undergo cataract surgery might have a decreased risk of developing Alzheimer’s disease and dementia.”

For their study, Dr. Lee and her team analyzed data from over 3,000 participants in the ongoing Adult Changes in Thought Study.

When participants in the Adult Changes in Thought Study enrolled, they were aged 65 years or older and did not have dementia. The researchers followed up with them every 2 years until dementia symptoms or Alzheimer’s disease presented themselves.

Kaiser Permanente Washington collected data for this study from 1994–2018 and analyzed them between 2019–2021.

The analysis only included participants who had received a diagnosis of cataract or glaucoma before enrollment or during follow-up.

Upon extracting information on cataract surgeries from the study participants’ medical records, researchers found of the 3,038 study participants, 853 developed dementia, including 709 with Alzheimer’s disease. Additionally, 1,382 of the participants — or 45% of the total — underwent cataract surgery.

During further investigation, Dr. Lee and her team found the participants who underwent cataract surgery had an almost 30% less risk of developing dementia after their surgery.

The researchers also reported that glaucoma surgery did not affect dementia risk.

1 Comment

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One response to “Cataract surgery may lower dementia risk

  1. Interesting. The article does not mention blue light though.


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