Refractive Error Study in Children: Results from Shunyi District, China

PURPOSE: To assess the prevalence of refractive errors and vision impairmen t in school-age children in Shunyi District, northeast of Beijing, the Peop les Republic of China. METHODS: Random selection of village-based clusters was used to identify a sample of children 5 to 15 years of age. Resident registration books were u sed to enumerate eligible children in the selected villages and identify th eir current school. Ophthalmic examinations were conducted in 132 schools o n children from 29 clusters during May 1988 to July 1998, including visual acuity measurements, cycloplegic retinoscopy, cycloplegic autorefraction, o cular motility evaluation, and examination of the external eye, anterior se gment, media, and fundus. Independent replicate measurements of all childre n with reduced vision and a sample of those with normal vision were done fo r quality assurance monitoring in three schools. RESULTS: A total of 6,134 children from 4,338 households were enumerated, a nd 5,884 children (95.9%) were examined. The prevalence of uncorrected, pre senting, and best visual acuity 0.5 (20/40) or worse in at least one eye wa s 12.8%, 10.9%, and 1.8%, respectively; 0.4% had best visual acuity 0.5 or worse in both eyes. Refractive error was the cause in 89.5% of the 1,236 ey es with reduced vision, amblyopia in 5%, other causes in 1.5%, with unexpla ined causes in the remaining 4%. Myopia -0.5 diopter or less in either eye was essentially absent in 5-year-old children, but increased to 36.7% in ma les and 55.0% in females by age 15. Over this same age range, hyperopia 2 d iopters or greater decreased from 8.8% in males and 19.6% in females to les s than 2% in both. Females had a significantly higher risk of both myopia a nd hyperopia. CONCLUSIONS: Reduced vision because of myopia is an important public health problem in school-age children in Shunyi District. More than 9% of childre n could benefit from prescription glasses. Further studies are needed to de termine whether the upward trend in the prevalence of myopia continues far beyond age 15 and whether the development of myopia is changing for more re cent birth cohorts. (Am J Ophthalmol 2000;129:427-435. (C) 2000 by Elsevier Science Inc, All rights reserved.).