Prevalence of undercorrected refractive errors in elderly population aged 60 years and older in Dachang County, Shanghai

Abstract

Background The undercorrection of refractive error is becoming a major cause of reversible visual impairment worldwide.To investigate and reduce the rate of undercorrected refractive error is one of the primary missions to fight blindness in China. Objective This study was to analyze the prevalence of undercorrected refractive error in residents aged 60 years and older in Dachang County of Baoshan District, Shanghai. Methods This study followed Declaration of Helsinki, and informed consent was obtained from each subject before any medical examination.A cross-sectional study was performed and a random cluster sampling technique was used.All fieldwork was conducted from October to December 2009.All participants were urban population who were changed from the rural population in 10 years ago.The participants received detailed ophthalmic and medical examination, including a standardized refraction and visual acuity examinations, tonometry, slit lamp biomicroscopy, and fundus photography.The undercorrected refractive error was defined based on the criteria of the presenting study, including criterion 1 (the vision improved by ≥1 line after refraction), and criterion 2 (the vision improved by ≥2 lines after refraction). The demographic characteristics of the population with undercorrected refractive error were also analyzed. Results Among the 5 199 people in the project, 4 545 received survey, with the response rate 87.42%.The overall prevalence of undercorrected refractive error was 45.43% or 24.84% based on criterion 1 or criterion 2, respectively.Women and older age were significant risk factors of undercorrected refractive error.The prevalence of undercorrected refractive error was 53.54% for myopia only, 53.06% for hyperopia only, 38.37% for astigmatism only, 38.99% for myopia with astigmatism, and 36.75% for hyperopia with astigmatism.In 401 participants with visual impairment, the prevalence of undercorrected refractive error was 78.80% or 67.58% based on criterion 1 or criterion 2, respectively. Conclusions In rapid urbanization and aging community of Shanghai, undercorrected refractive error is an important cause that affecting the vision of older persons. Key words: Vision; Aged; Epidemiology; Community health services; Refractive error; Undercorrected; Visual impairment; Cross-sectional study