Refractive Error Study in Children: Results from La Florida, Chile

PURPOSE: To assess the prevalence of refractive errors and vision impairmen t in school-age children in a suburban area (La Florida) of Santiago, Chile . METHODS: Random selection of geographically defined clusters was used to id entify a representative sample of children 5 to 15 years of age. Children i n the 26 selected clusters were enumerated through a door to-door survey an d invited to report to a community health clinic for examination. Visual ac uity measurements, cycloplegic retinoscopy, cycloplegic autorefraction, ocu lar motility evaluation, and examination of the external eye, anterior segm ent, media, and fundus were done from April through August 1998. Independen t replicate examinations of all children with reduced vision and a sample o f those with normal vision were done for quality assurance monitoring in si x clusters. RESULTS: A total of 6,998 children from 3,830 households were enumerated, a nd 5,303 children (75.8%) were examined, The prevalence of uncorrected, pre senting, and best visual acuity 0.50 (20/40) or worse in at least one eye w as 15.8%, 14.7%, and 7.4%, respectively; 3.3% had best visual acuity 0.50 o r worse in both eyes. Refractive error was the cause in 56.3% of the 1,285 eyes with reduced vision, amblyopia in 6.5%, other causes in 4.3%, with une xplained causes in the remaining 32.9%. Myopia -0.50 diopter or less in eit her eye was present in 3.4% of 5-year-old children, increasing to 19.4% in males and 14.7% in females by age 15. Over this same age range, hyperopia 2 .00 diopters or greater decreased from 22.7% to 7.1% in males and from 26.3 % to 8.9% in females. Females had a significantly higher risk of hyperopia than males. CONCLUSIONS: Refractive error, associated primarily with myopia, is a major cause of reduced vision in school-age children in La Florida. More than 7% of children could benefit from the provision of proper spectacles. Efforts are needed to make existing programs that provide free spectacles for scho ol children more effective. Further studies are needed to determine whether the upward trend in myopia continues far beyond 15 years of age. (Am J Oph thalmol 2000;129:445-454. (C) 2000 by Elsevier Science Inc. All rights rese rved.).