Age-related cataract and 10-year mortality: the Liwan Eye Study

Purpose To explore the association between age-related cataract and 10-year mortality in an adult population in urban China. Methods A total of 1405 participants aged 50 years or older were examined at baseline in the Guangzhou Liwan Eye Study. All participants were invited to attend a 10-year follow-up visit. Cataract cases were defined as either having visible lens opacity confirmed with direct ophthalmoscope under pupil dilation or previous history of cataract surgery. Visual impairment (VI) was defined as a visual acuity of 20/40 or worse in the better-seeing eye with habitual correction if worn. Body mass index (BMI) was based on anthropometric data. A brief questionnaire regarding family income, educational attainment and medical history of systemic disease was administered. Mortality rates were compared using the log-rank test and Cox proportional hazards regression models. Results Among 1405 participants examined at baseline, 957 participants (68.1%) had visible lens opacity or history of cataract surgery. After 10 years, 320 (22.8%) participants died. The 10-year mortality rate was significantly higher in participants with cataract than in those without (30.1% versus 7.14%, log-rank p < 0.05). After adjusting for age, gender, family income, educational attainment, BMI, history of diabetes and hypertension and presence of VI, presence of cataract predicted a nearly threefold increase in the risk of mortality (HR, 2.99; 95% CI, 1.89-4.71). Conclusions Our findings that age-related cataract is a predictor for poorer survival compared to those without may imply that cataract is a biomarker of ageing and frailty.