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 versusurban 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.