Visual impairment as a risk factor of cognitive function impairment A six-year cohort study

PURPOSE To explore whether baseline visual impairment (VI) increases the risk of cognitive function impairment (CFI). METHODS We conducted a population-based cohort study, with a six-year follow-up period. The exposure factor of interest in this study was VI. The Mini-Mental State Examination (MMSE) was used to assess participants' cognitive function. The Logistic regression model was used to investigate whether baseline VI had an effect on CFI. Confounding factors were adjusted in the regression model. The odds ratio (OR) and 95% confidence interval (CI) were used to quantify the effect of VI on CFI. RESULTS A total of 3297 participants were included in the present study. The mean age of included participants was 58.5 ± 7.2 years. Male accounted for 1480 (44.9%) of all participants. At baseline, 127 (3.9%) of the participants had VI. The MMSE score of participants who had VI at baseline decreased by 1.7 ± 3.3 points on average during the six-year follow-up, and that of participants who had no VI at baseline decreased by 1.1 ± 3.3 points on average. The difference was significant (t = 2.03, p = 0.040). Results of the multivariable Logistic regression model showed that VI was a risk factor for CFI, with an OR of 1.052 (95%CI: 1.014 to 1.092, p = 0.017). CONCLUSIONS Averagely, participants with VI experienced a decline in cognitive function 0.1 points faster per year than participants without VI, as measured by MMSE score. VI is an independent risk factor for CFI.