Impact of cataract surgery on cognitive impairment in older people

To examine the impact of cataract surgery on mild cognitive impairment (MCI) and dementia in older people.

This prospective observational study included patients aged 75 years and older who underwent cataract surgery between 2019 and 2021. Mini-mental state examination (MMSE) and MMSE for the visually impaired (MMSE-blind) were measured to evaluate cognitive function before and 3 months after cataract surgery. MMSE score at baseline was used to categorize patients into dementia (MMSE ≤ 23) and MCI groups (23 < MMSE ≤ 27). Logistic regression models were used to estimate associations between improvement in cognitive function and other factors.

Of 132 patients screened for inclusion in the study, 88 met the inclusion criteria; 39 patients were assigned to the dementia group (mean age, 85.7 ± 4.2 years) and 49 to the MCI group (mean age, 84.2 ± 3.4 years). The MCI group showed significant improvement from before to after surgery in the MMSE score (25.65 ± 1.03 vs. 27.08 ± 1.99, respectively, p < 0.001) and MMSE-blind score (18.04 ± 1.14 vs. 19.41 ± 2.01, respectively, p < 0.001). Cognitive function improved significantly in the MCI group compared with the dementia group (odds ratio, 2.85; 95% confidence interval, 1.02-7.97; and p = 0.046).

Cataract surgery significantly increases cognitive test scores in older patients with MCI. After cataract surgery, the likelihood of improvement in cognitive function may be highly dependent on a patient's preoperative cognitive state.