title: [Prevalence of refractive errors in students in Northeastern Brazil].
abstract: OBJECTIVE
  To determine the prevalence of refractive errors in the public and private school system in the city of Natal, Northeastern Brazil.
  
  
  METHODS
  Refractometry was performed on both eyes of 1,024 randomly selected students, enrolled in the 2001 school year and the data were evaluated by the SPSS Data Editor 10.0. Ametropia was divided into: 1- from 0.1 to 0.99 diopter (D); 2- 1.0 to 2.99 D; 3- 3.00 to 5.99 D and 4- 6D or greater. Astigmatism was regrouped in: I- with-the-rule (axis from 0 to 30 and 150 to 180 degrees), II- against-the-rule (axis between 60 and 120 degrees) and III- oblique (axis between > 30 and < 60 and >120 and <150 degrees). The age groups were categorized as follows, in: 1- 5 to 10 years, 2- 11 to 15 years, 3- 16 to 20 years, 4- over 21 years.
  
  
  RESULTS
  Among refractive errors, hyperopia was the most common with 71%, followed by astigmatism (34%) and myopia (13.3%). Of the students with myopia and hyperopia, 48.5% and 34.1% had astigmatism, respectively. With respect to diopters, 58.1% of myopic students were in group 1, and 39% distributed between groups 2 and 3. Hyperopia were mostly found in group 1 (61.7%) as well as astigmatism (70.6%). The association of the astigmatism axes of both eyes showed 92.5% with axis with-the-rule in both eyes, while the percentage for those with axis against-the-rule was 82.1% and even lower for the oblique axis (50%).
  
  
  CONCLUSIONS
  The results found differed from those of most international studies, mainly from the Orient, which pointed to myopia as the most common refractive error, and corroborates the national ones, with the majority being hyperopia.
authors.affiliation: Federal University of Rio Grande do Norte, Natal, Brazil. prontoc.de.olhos@digi.com.br
authors.forename: Carlos Alexandre de Amorim
authors.initials: CA
authors.lastname: Garcia
authors.forename: Fernando
authors.initials: F
authors.lastname: Oréfice
authors.forename: Gabrielle Fernandes Dutra
authors.initials: GF
authors.lastname: Nobre
authors.forename: Dilene de Brito
authors.initials: Dde B
authors.lastname: Souza
authors.forename: Marta Liliane Ramalho
authors.initials: ML
authors.lastname: Rocha
authors.forename: Raul Navarro Garrido
authors.initials: RN
authors.lastname: Vianna
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D001251:Astigmatism / Q000175:diagnosis / Q000453:epidemiology*; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D006801:Humans; D006956:Hyperopia / Q000175:diagnosis / Q000453:epidemiology*; D008875:Middle Aged; D009216:Myopia / Q000175:diagnosis / Q000453:epidemiology*; D015995:Prevalence; D012029:Refraction, Ocular