Prevalence of trachoma in the adult Chinese population. The Beijing Eye Study

Purpose To determine the prevalence of trachoma in the adult Chinese population. Methods The Beijing Eye Study as a population-based, cross-sectional cohort study included 4439 subjects out of 5324 subjects invited to participate with an age of 40+ years. Trachomatous abnormalities were assessed by slit lamp examination. Examination data were available for 4411 (99.4%) subjects. Results Trachomatous abnormalities were present in 850 eyes (mean +/- SE: 9.64 +/- 3.14%) or 422 subjects (9.57 +/- 0.44%), differentiated into follicular trachomatous inflammation ( stage 1) (0.92 +/- 0.11%), intensive trachomatous inflammation (stage 2) (1.01 +/- 0.11%), trachomatous scarring ( stage 3) (7.61 +/- 0.29%), and trachomatous trichiasis ( stage 4) (0.47 +/- 0.08%). Trachomatous scarring was significantly associated with higher age (P < 0.001), low level of education (P < 0.001), rural versus urban region (P = 0.04), and low visual acuity (P < 0.001). Conclusion Active trachoma is present in about 2 out of 100 Chinese adults, and trachomatous scarring is present in about in about 8 out of 100 Chinese adults in Northern China with age, socioeconomic background, and rural region as main risk factors.