Abstract:Objective To analyze the prevalence, distribution characteristics, etiologies and risk factors of blindness and low vision among people aged 40 years and above in Xilinguole League.

Abstract:

Abstract? Objective：To investigate the prevalence, epidemiological distribution, primary etiological factors, and associated risk factors of blindness and low vision among residents aged 40 years and older in Xilingol League.? Methods：A multistage clustersampling design was adopted. A total of 1?429 participants were enrolled, and 1?295 completed the whole survey with a response rate of 90.62?%. Standardized ophthalmic examinations and MongolianChinese bilingual questionnaire surveys were performed for all subjects. Grading of blindness and lowvision was conducted according to the World Health Organization 2009 criteria aligned with the ICD11 system, based on the bestcorrected visual acuity (BCVA) of the betterseeing eye. The chisquare test was used for intergroup comparisons, and multivariate Logistic regression was applied to explore factors associated with visual impairment. Results：The prevalence of blindness, low vision, and overall visual impairment in the study population was 0.3%, 3.3%, and 3.7%, respectively. The overall prevalence of visual impairment was 3.9% in pastoral areas and 3.2% in urban areas, with no statistically significant difference between the two groups (P = 0.696). The prevalence of visual impairment increased significantly with age, and the low vision prevalence reached 18.0% among individuals aged 80 years and above (trend χ² = 44.35, P < 0.001). The overall prevalence of visual impairment in the Mongolian population (2.9%) was lower than that in the Han population (5.0%). Cataract was the leading cause of visual impairment, accounting for 78.3% of all affected cases. The unoperated rate of cataract was 80.0% in pastoral areas and 78.7% in urban areas. Multivariate Logistic regression analysis demonstrated that age ≥ 80 years was an independent risk factor for visual impairment (OR = 5.86, 95%CI: 2.71–12.67, P < 0.001). Regular dairy product consumption was significantly correlated with a lower risk of visual impairment (OR = 0.45, 95%CI: 0.24–0.84, P = 0.012). Diabetes mellitus, hypertension, and primary school education or below were not identified as independent risk factors for visual impairment (all P > 0.05). Conclusions：The overall prevalence of blindness and low vision among residents aged 40 years and above in Xilingol League was 3.7%. Advanced age was identified as an independent risk factor for visual impairment. Dairy product intake was protectively correlated with visual impairment, although a causal relationship could not be determined. Cataract remained the leading cause of visual impairment. The accessibility of cataract surgery in pastoral areas still needs urgent improvement. Key Words：Blindness; Low Vision; Prevalence; Risk Factors; Epidemiological Investigation