To investigate the correlation between cataract surgery and cognitive function using the Korean-mini mental state Examination (K-MMSE).

We performed cataract extraction with phacoemulsification and intraocular lens implantation in 138 eyes of 87 patients, from 2014 to 2016, with subjective cognitive complaints. K-MMSE was used to measure cognitive function of the patients before and after surgery, and the results were analyzed using the paired t -test.

The mean age of the patients was 76.09 ± 6.52 years. The preoperative mean K-MMSE score was 23.44 ± 4.12 and the postoperative mean K-MMSE score was 24.49 ± 3.19. The increase in the postoperative K-MMSE score from that of the preoperative score was significant. Among the 87 patients who participated in the study, 36 patients were treated with unilateral cataract surgery and 51 patients were treated with bilateral cataract surgery. The mean ages were 76.36 ± 6.68 years and 75.90 ± 6.47 years, respectively. The mean K-MMSE scores significantly increased in both unilateral and bilateral patients (0.91 ± 1.96 and 1.15 ± 2.73 points, respectively). The difference in the increase in the mean K-MMSE score was not significant between the two groups. When analyzed according to the K-MMSE score, only those who initially scored < 23 points showed significant improvement in cognition function, which was not associated with the improvement in the best-corrected visual acuity improvement.

There was an improvement of the K-MMSE score after cataract surgery, indicating that cataract surgery not only enhanced visual acuity but also had a positive effect on the patients' cognitive function. When considering cataract surgery in older patients, this improvement in cognition could lead to a better life, which should be taken into consideration.