The excess burden of trachomatous trichiasis in women: a systematic review and meta-analysis

It is widely accepted that women carry an increased burden of trachomatous trichiasis compared with men, but there is no systematic review of the available prevalence surveys in the peer-reviewed literature. A literature search was conducted to identify population-based trachoma prevalence surveys utilising the WHO simplified grading system that included data for trichiasis. Of 53 identified studies, 24 studies from 12 different countries met the inclusion criteria. Prevalence data were pooled in a meta-analysis to estimate an overall odds ratio (OR). The overall odds of trichiasis in women compared with men was 1.82 (95% CI 1.61-2.07). Individual survey ORs ranged from 0.83 (95% CI 0.40-1.73) in Myanmar to 3.82 (95% CI 2.36-6.19) in Ethiopia. There were statistically significant differences in odds of trichiasis by gender in 17 of 24 studies, all of which showed increased odds of trichiasis in women compared with men. These data confirm the perception that women have a greater burden of trichiasis, and this burden persists across all populations studied. Women must be specifically and deliberately targeted for trichiasis surgery if the aim of eliminating blindness from trachoma is to be achieved.