Global prevalence and epidemiological characteristics of congenital cataract: a systematic review and meta-analysis

Abstract

BackgroundCongenital cataract is the primary cause of treatable childhood blindness worldwide. The establishment of reliable, epidemiological estimates is an essential first step towards development of causal and management strategies. We therefore undertook an initial systematic review and meta-analysis to estimate the global prevalence and other epidemiological characteristics of congenital cataract. MethodsWe searched PubMed, Medline, Web of Science, Embase, and Cochrane Library databases with a combination of search terms, including “congenital cataract”, “prevalence”, “epidemiology”, “population”, and “survey”, up to January, 2015. We did a meta-analysis with a random-effects model based on a proportions approach to determine the population-based prevalence of congenital cataract and to describe the data for the laterality, morphology, associated comorbidities, and cause. We analysed heterogeneity with the meta-regression method, and did subgroup analyses. Findings27 studies were selected from 2610 references. The pooled prevalence estimate was 4·24 per 10 000 people (95% CI 3·16–5·69 per 10 000), making it a rare disease by WHO standards. Most of the variations could be explained by sample size, research period, and age at diagnosis (R2, amount of heterogeneity accounted for, 65·41%; p=0·0006). Subgroup analyses showed that the highest prevalence of congenital cataract was in Asia, and a trend for increasing prevalence through 2000 in all regions. Other major epidemiological characteristics showed that congenital cataract tended to be bilateral, isolated, hereditary, and in total/nuclear morphology. InterpretationThis study provides a comprehensive, worldwide estimate of the population-based prevalence of congenital cataract and describes its major epidemiological characteristics. The findings provide suggestions for further studies focused on the cause of congenital cataract, improvements in screening techniques, and the development of public health strategies. FundingThe Ministry of Science and Technology of China Grants (973 programme, 2015CB964600), the Key Research Plan for the National Natural Science Foundation of China (number 91546101), and the Guangdong Provincial Natural Science Foundation for Distinguished Young Scholars of China (number 2014A030306030).