Association Found Between Cataract Surgery and Lower Risk of Dementia

Cataracts, or the gradual clouding of the eye lens, is very common in older adults. More than 90% of people over the age of 65 in the United States will develop them. Luckily, cataracts are very treatable. Surgical operations to remove cataracts are 90% effective in restoring useful vision, have a low chance of complication, and usually cause little to no pain. 

As well as restoring vision, cataract surgery is associated with many quality-of-life improvements. Patients that undergo successful cataract surgery have been found to have lower rates of depression and lower chances of accidental injuries. The restoration of sight is already one of the most effective and beneficial procedures for older adults. But there could be another critical benefit for cataract surgery patients.

The connections between many of the ailments that affect our physical and mental well-being were once largely unexplored. But today, the groundbreaking work of industry-leading health professionals and researchers is beginning to show that many medical conditions are actually interrelated. New evidence suggests that cataract surgery is connected to a lower risk of dementia. 

The evidence

Between 2019 and 2021, a Washington state-based Adult Changes in Thought (ACT) study randomly selected over 3,000 cognitively normal older adults and tracked both their cataract surgery and cognitive function. The study, published by lead researcher Dr. Cecilia S. Lee and coauthors Dr. Laura E. Gibbons and Dr. Aaron Y. Lee, ultimately found compelling evidence that cataract surgery is associated with a 30% lower risk of dementia. The study was approved by institutional review boards at Kaiser Permanente Washington and the University of Washington and published early this December 2021 in JAMA Internal Medicine. 

Because of their implications, these findings are making noise all over the medical community. Dr. Lee has been quoted saying, “This kind of evidence is as good as it gets in epidemiology.” 

The exact reason that cataract surgery and a lower risk of dementia are associated is still not entirely understood, but there are several hypotheses. Lee and other researchers have noted that the “visual cortex undergoes structural change with vision loss,” and one study even suggests that visual restoration can promote structural recovery of brain material, or grey matter. This is to say that the deterioration of vision might also lead to cognitive deterioration, but also that the recovery of vision could promote structural recovery in the brain. Cataract surgery might be all the more beneficial for older patients.

And the connections between vision and brain function extend further. One study finds evidence of an association between age-related hearing impairment and dementia. Sensory loss itself, then, could affect cognition. 

What are the implications?

While not as common as cataracts, dementia affects an estimated 50 million people worldwide. Unfortunately, treatment for dementia is not nearly as effective as cataract surgery. Reducing the risk or delaying the onset of dementia are therefore increasingly important. Addressing the conditions that might lead to future cognitive degeneration, like vision impairment, are essential in treating dementia.

Cataract surgery already empowers patients to see clearly and live confidently. Now this treatment could also become essential in lowering the risk of dementia or other cognitive diseases. Empower yourself by taking both your sensory and mental health into your own hands.