[Prevalence and risk factors of pterygium in Han and Yugur populations in Gansu Province, China].

Objective: To investigate the prevalence and risk factors of pterygium in Han and Yugur populations aged 40-79 years in Gansu Province, China. Methods: This was a cross-sectional study. A multistage cluster sampling method with urbanization level-based stratification was employed. Multiple logistic regression analysis was performed to evaluate the risk factors of pterygium. Results: A total of 4 193 people (1 840 males, 2 353 females; 3 035 Hans, 1 158 Yugurs) aged over 40 in Gansu Province were included in the study. Among them, 391 patients (9.3%) were found to have pterygium. The prevalence of pterygium adjusted for age and sex was 9.3%. The prevalence rates of Han and Yugur participants were 8.8% (267 patients) and 10.7% (124 patients), respectively, and there was no significant difference between them (χ²=3.629, P=0.057). Multivariate regression analysis showed that the risk factors of pterygium included age (OR=3.66, 95%CI: 2.26-5.92), length of residence in the countryside (OR=2.18, 95%CI: 1.41-3.38), and education level (OR=0.49, 95%CI: 0.29-0.83). In the Han group, the risk factors of pterygium were age (OR=3.84, 95%CI: 2.18-6.78) and length of rural residence (OR=2.02, 95%CI: 1.23-3.33), and a higher level of education (OR=0.36, 95%CI: 0.20-0.66) was a protective factor. Older age (OR=3.11, 95%CI: 1.13-8.59) and rural residential length ratio (OR=3.28, 95%CI: 1.09-9.88) were risk factors for pterygium in Yugur population. Conclusions: The overall prevalence of pterygium in Han and Yugur populations aged over 40 in Gansu Province, China was 9.3%, with no significant difference between the two nationalities. Older age and rural residency increased the incidence of pterygium, and a higher education level was a protective factor for pterygium.(Chin J Ophthalmol, 2020, 56:600-607).