Is It Because of the 'Blue Light'?..."Cataract Surgery in Elderly Lowers Dementia Risk by 30%"

Those without surgery face greater social isolation due to visual impairment and decreased physical activity, leading to reduced cognitive ability.

(Photo by Getty Images)

[Asia Economy Senior Reporter Jinsoo Lee] Elderly individuals who have undergone cataract surgery were found to have a 30% lower risk of developing dementia compared to those who have not had the surgery.

A research team from the University of Washington School of Medicine in the United States revealed this in a paper published online on the 6th (local time) in the 'JAMA Internal Medicine' journal, introducing the conclusion drawn from a study of more than 3,000 elderly people aged 66 and older.

Cataracts are a condition in which the lens inside the eye becomes cloudy and opaque due to various causes, leading to visual impairment. In some cases, cataracts occur congenitally due to genetic factors or rubella infection during early pregnancy.

However, most cataracts are acquired, caused by aging, trauma, systemic diseases, inflammation inside the eye, toxins, and so on. In particular, senile cataracts, which develop as part of aging, are very common, with more than half of people in their 60s and the majority of those over 75 having some degree of the condition.

Among the subjects tracked over 10 years, none had memory impairment at the start of the study.

The researchers began tracking 3,038 individuals diagnosed with cataracts or glaucoma. Their average age was 74 years.

Subsequently, nearly half of them, 1,382 people, underwent cataract surgery. Cataract surgery involves two stages: removing the clouded lens and implanting an artificial intraocular lens.

After following the subjects for an average of 8 years, 853 of them developed dementia.

(Photo by Getty Images)

The investigation showed that those who had cataract surgery were 29% less likely to be diagnosed with dementia compared to those who did not have the surgery. The lowest risk of dementia was observed within 5 years after cataract surgery, with a 32% reduction. In the following 5 years, the risk was confirmed to be 24% lower.

The researchers pointed out that those who did not undergo cataract surgery might experience greater social isolation due to visual impairment, leading to reduced brain stimulation and progression to dementia. Visual impairment caused by cataracts can also lead to decreased physical activity, which in turn lowers cognitive ability.

The research team did not determine why cataract surgery reduces the risk of dementia. The eyes of elderly patients who have undergone surgery can receive more blue light. The researchers speculate that this might lower the risk of dementia. They are considering that blue light may reactivate retinal cells related to cognition and sleep.

Cecilia Lee, assistant professor of ophthalmology at the University of Washington School of Medicine and lead of this study, explained, "Some retinal cells are associated with cognition and sleep cycles," adding, "These cells respond well to blue light."

This content was produced with the assistance of AI translation services.