Cataract-related visual impairment corrected by cataract surgery and 10-year mortality: The Liwan Eye Study

Abstract

PURPOSE. To assess 10-year mortality in people who had undergone cataract surgery with no residual visual impairment (VI) and those who had persistent VI due to cataract using a population-based cohort. METHODS. The Liwan Eye Study is a 10-year longitudinal study commenced in 2003. According to the World Health Organization, presenting VI was defined as visual acuity less than 20/63 in the better-seeing eye. History of cataract surgery was defined as cataract surgery performed on either eye. Information on the date of surgery was recorded. Dates of death occurring between baseline and April 30, 2014 were obtained from the National Death Index data. Information on socioeconomic factors was obtained from questionnaire interviews. Cox proportional hazards regression models were used to assess the hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS. Fifty-nine participants had undergone cataract surgery without residual VI and 67 participants had persistent cataract-related VI. The 10-year mortality rate for participants who had undergone cataract surgery without residual VI was statistically significant lower than that in participants who had VI due to cataract based on log-rank test (32.2% vs. 64.2%; P ¼ 0.002). This finding remained significant in the unadjusted Cox proportional hazards model (HR, 0.43; 95% CI, 0.25–0.74; P ¼ 0.002). After adjusting for age, sex, history of diabetes, and hypertension, body mass index (BMI), education level, and personal income, participants with cataract surgery and no residual VI did not have a higher chance of survival than participants with persistent VI due to cataract (HR, 0.56; 95% CI, 0.26–1.20; P ¼ 0.136). CONCLUSIONS. Cataract-related VI corrected by cataract surgery was not associated with better survival after adjusting for a number of possible confounders. Given our sample size is relatively small and limited power, further studies with larger sample are needed.