Refractive Error Study in Children: sampling and measurement methods for a multi-country survey

Am J Ophthalmol. 2000 Apr;129(4):421-6. doi: 10.1016/s0002-9394(99)00455-9.


Purpose: The Refractive Error Study in Children was designed to assess the prevalence of refractive error and vision impairment in children of different ethnic origins and cultural settings.

Methods: Population-based cross-sectional samples of children 5 to 15 years of age were obtained through cluster sampling. Presenting, uncorrected, and best-corrected visual acuity, along with refractive error under cycloplegia, were the main outcome measures. Amblyopia and other causes of uncorrectable vision impairment were determined.

Results: Study design and sample size calculations, survey enumeration and ophthalmic examination methods, quality assurance monitoring, and da ta analyses and statistical methods are described.

Conclusions: The study design, sample size, and measurement methods ensure that the prevalence of age-specific and sex-specific refractive error can be estimated with reasonable accuracy in the target populations. With commonality of methods, a comparison of findings between studies in different ethnic origins and cultural settings is possible.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Child
  • Child, Preschool
  • Chile / epidemiology
  • China / epidemiology
  • Cross-Sectional Studies
  • Epidemiologic Methods
  • Female
  • Health Surveys
  • Humans
  • Male
  • Nepal / epidemiology
  • Prevalence
  • Refractive Errors / ethnology*
  • Sampling Studies
  • Vision Disorders / ethnology*
  • Visual Acuity