title: Prevalence of refractive error among preschool children in an urban population: the Baltimore Pediatric Eye Disease Study.
abstract: OBJECTIVE
  To determine the age-specific prevalence of refractive errors in white and African-American preschool children.
  
  
  METHODS
  The Baltimore Pediatric Eye Disease Study is a population-based evaluation of the prevalence of ocular disorders in children aged 6 to 71 months in Baltimore, Maryland.
  
  
  METHODS
  Among 4132 children identified, 3990 eligible children (97%) were enrolled and 2546 children (62%) were examined.
  
  
  METHODS
  Cycloplegic autorefraction was attempted in all children with the use of a Nikon Retinomax K-Plus 2 (Nikon Corporation, Tokyo, Japan). If a reliable autorefraction could not be obtained after 3 attempts, cycloplegic streak retinoscopy was performed.
  
  
  METHODS
  Mean spherical equivalent (SE) refractive error, astigmatism, and prevalence of higher refractive errors among African-American and white children.
  
  
  RESULTS
  The mean SE of right eyes was +1.49 diopters (D) (standard deviation [SD] = 1.23) in white children and +0.71 D (SD = 1.35) in African-American children (mean difference of 0.78 D; 95% confidence interval [CI], 0.67-0.89). Mean SE refractive error did not decline with age in either group. The prevalence of myopia of 1.00 D or more in the eye with the lesser refractive error was 0.7% in white children and 5.5% in African-American children (relative risk [RR], 8.01; 95% CI, 3.70-17.35). The prevalence of hyperopia of +3 D or more in the eye with the lesser refractive error was 8.9% in white children and 4.4% in African-American children (RR, 0.49; 95% CI, 0.35-0.68). The prevalence of emmetropia (<-1.00 D to <+1.00 D) was 35.6% in white children and 58.0% in African-American children (RR, 1.64; 95% CI, 1.49-1.80). On the basis of published prescribing guidelines, 5.1% of the children would have benefited from spectacle correction. However, only 1.3% had been prescribed correction.
  
  
  CONCLUSIONS
  Significant refractive errors are uncommon in this population of urban preschool children. There was no evidence for a myopic shift over this age range in this cross-sectional study. A small proportion of preschool children would likely benefit from refractive correction, but few have had this prescribed.
authors.affiliation: Dana Center for Prevention Ophthalmology, Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, Maryland 21210, USA.
authors.forename: Lydia
authors.initials: L
authors.lastname: Giordano
authors.forename: David S
authors.initials: DS
authors.lastname: Friedman
authors.forename: Michael X
authors.initials: MX
authors.lastname: Repka
authors.forename: Joanne
authors.initials: J
authors.lastname: Katz
authors.forename: Josephine
authors.initials: J
authors.lastname: Ibironke
authors.forename: Patricia
authors.initials: P
authors.lastname: Hawes
authors.forename: James M
authors.initials: JM
authors.lastname: Tielsch
mesh_terms: D001741:Black or African American; D015142:Baltimore / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009184:Mydriatics / Q000008:administration & dosage; D015995:Prevalence; D011680:Pupil / Q000187:drug effects; D012029:Refraction, Ocular; D012030:Refractive Errors / Q000453:epidemiology*; D042262:Retinoscopy; D014505:Urban Population / Q000706:statistics & numerical data*; D014787:Vision Tests; D044465:White People
chemical_list: D009184:Mydriatics