Refractive Error, Visual Acuity and Causes of Vision Loss in Children in Shandong, China. The Shandong Children Eye Study

To examine the prevalence of refractive errors and prevalence and causes of vision loss among preschool and school children in East China.Using a random cluster sampling in a cross-sectional school-based study design, children with an age of 4–18 years were selected from kindergartens, primary schools, and junior and senior high schools in the rural Guanxian County and the city of Weihai. All children underwent a complete ocular examination including measurement of uncorrected (UCVA) and best corrected visual acuity (BCVA) and auto-refractometry under cycloplegia. Myopia was defined as refractive error of ≤−0.5 diopters (D), high myopia as ≤−6.0D, and amblyopia as BCVA ≤20/32 without any obvious reason for vision reduction and with strabismus or refractive errors as potential reasons.0.001;OR:1.47;95%CI:1.31,1.64). BCVA was ≤20/40 in the better eye in 19 (0.32%) children. UCVA ≤20/40 in at least one eye was found in 2046 (34.05%) children, with undercorrected refractive error as cause in 1975 (32.9%) children. Amblyopia (BCVA ≤20/32) was detected in 44 (0.7%) children (11 children with bilateral amblyopia).In coastal East China, about 14% of the 17-years olds were highly myopic, and 80% were myopic. Prevalence of myopia increased with older age, female gender and urban region. About 0.7% of pre-school children and school children were amblyopic