Prevalence and risk factors of cataract among residents aged 50 years and older in Hainan province

  Objective  To investigate the prevalence and the risk factors of cataract in the residents aged ≥ 50 years in Hainan province.

  Methods  Using cluster random sampling, we conducted a questionnaire survey and ocular examination among 2 400 permanent residents aged ≥ 50 years in four cities with different geographic location in Hainan province from January 2014 to June 2016. We adopted Lens Opacity Classification System III (LOCS III) in diagnosis of cataract. Chi- square test, rank sum test and logistic regression were used in data analyses.

  Results  Of the 2 243 residents with valid information, 787 (35.1%) were diagnosed with cataract. Elder age and lower education were risk factors of cataract for the residents. Among the 1439 cataract eyes diagnosed, the proportions were 32% for nuclear opacity, 0.4% for cortical opacity, 1.5% for posterior capsular opacity, and 66.1% for mixed lens opacity.

  Conclusion  For 50 years and older residents in Hainan province, the prevalence of cataract is relatively high and mainly influenced by age and education; mixed lens opacity is the main type of cataract, followed by nuclear opacity. The results suggest interventions on cataract should be promoted in the population.