Prevalence and risk factors for cataracts in the Lao People's Democratic Republic: The Vientiane Eye Study

Purpose: To determine the prevalence and risk factors for cataracts in the Vientiane Province. Methods: We conducted a population-based study of 1264 participants aged & GE;40 years of age from urban and rural areas of Vientiane Province. Data collection included demographic information, smoking history, body mass index, blood pressure, history of trauma and dilated lens examination using the World Health Organization WHO Simplified Cataract Grading System. Aphakic and pseudophakic eyes were included as operated cataracts for statistical analysis. Results: The mean age of the 1264 participants was 57.6 years. The prevalence of any cataract including operated eyes was 46.8% (95% CI: 44.1 - 49.6%): 36.9% nuclear, 21.7% cortical and 10.1% posterior subcapsular cataracts. Conclusion: The prevalence of cataract in the Vientiane Eye Study is similar compared to the prevalence reported in other studies from Asian regions; however, the median age in this study was low, reflecting the age group of the population and the rapid urbanisation occurring in the Lao People's Democratic Republic. A significant association for any cataract was found with elevated blood pressure > 148mmHg (OR2.48, 95%CI:1.55 - 3.97, P < 0.01), increasing age (OR1.19, 95%CI:1.17 - 1.22, P < 0.001) and rural inhabitants for cortical cataract (OR1.99, 95%CI:1.37 - 2.90, P < 0.001). An inverse relationship between rural inhabitants with any cataract and nuclear cataract was found (OR 0.63, 95%CI: 0.45 - 0.89, P < 0.01 and OR 0.42, 95%CI: 0.31 - 0.59, P < 0.001) respectively. Nevertheless, cataract remains a high prevalence disease in this population.