High Prevalence of Myopia and High Myopia in 5060 Chinese University Students in Shanghai

PURPOSE. Myopia is an important cause of correctable visual impairment worldwide. Genetic and environmental factors contribute to its development. The population of Chinese university students consists of approximately 30 million young people characterized by academic excellence and similar ages. To date, little is known about their refractive status. Our study is designed to investigate the prevalence of myopia in this specific population. METHODS. This is a cross-sectional study of myopia among university students in Shanghai, China; 5083 students from Donghua University were enrolled. All participants first responded to a detailed questionnaire, including questions on ethnicity, birth date, and family history, and then undertook a standardized ophthalmologic examination, including visual acuity, a slit-lamp examination, and non-cycloplegic auto-refraction. RESULTS. The mean spherical equivalent refraction (SER) of the university students was -4.1 diopters (D). Of the subjects 95.5% were myopic (SER < -0.50 D), 19.5% were highly myopic (SER < -6.0 D), and only 3.3% were emmetropic (-0.5 D <= SER <= 0.5 D). The postgraduates were more myopic than the undergraduates (96.9% and 94.9%, respectively). Being female (-4.1 +/- 2.4 D in female versus -3.8 +/- 2.4 D in male subjects), of Han ethnicity (-4.1 +/- 2.4 D in Han versus -3.4 +/- 2.2 D in minorities), and of older age were associated with a higher probability of myopia only in the undergraduate population. CONCLUSIONS. The prevalence of myopia and high myopia in this university student population was high. The refractive status of this population deserves further attention. (Invest Ophthalmol Vis Sci. 2012; 53: 7504-7509) DOI:10.1167/iovs.11-8343