title: Cost-efficient vision screening for astigmatism in native american preschool children.
abstract: OBJECTIVE
  To design and test a cost-efficient, community-based vision screening program for a population of Native American preschool children in which there is a high prevalence of astigmatism.
  
  
  METHODS
  Based on analysis of vision screening and eye examination data from a preschool population with a 33% prevalence of astigmatism, comparative costs to conduct a 1000-child screening program with a target sensitivity of 90% were estimated for photoscreening, noncycloplegic autorefraction, autokeratometry, and Lea symbols distance visual acuity testing. Results of the cost analysis and examination of sensitivity and specificity data from the preschool population led to development of a hybrid screening program of autokeratometry and visual acuity screening with referral thresholds of 2.25 D of corneal astigmatism or inability to read a 20/63 Lea symbols line on two separate attempts. The screening program was prospectively implemented in a community-based screening of a similar cohort of 167 children, and its efficiency was evaluated by comparison to results of cycloplegic refraction.
  
  
  RESULTS
  The community-based screening showed 96.8% sensitivity and 79.2% specificity for detecting the presence of refractive astigmatism of 1.50 D or more.
  
  
  CONCLUSIONS
  Referring children who have at least 2.25 D of corneal astigmatism or acuity worse than 20/63 on two attempts, provides the high sensitivity and specificity associated with automated keratometry while maintaining an acuity component that can detect other causes of reduced acuity in the absence of astigmatism.
authors.affiliation: Department of Ophthalmology, The Optical Sciences Center, The University of Arizona, Tucson, Arizona 85711, USA. jmiller@eyes.arizona.edu
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Miller
authors.forename: Velma
authors.initials: V
authors.lastname: Dobson
authors.forename: Erin M
authors.initials: EM
authors.lastname: Harvey
authors.forename: Duane L
authors.initials: DL
authors.lastname: Sherrill
mesh_terms: D001251:Astigmatism / Q000175:diagnosis* / Q000191:economics* / Q000453:epidemiology / Q000628:therapy; D002675:Child, Preschool; D003362:Cost-Benefit Analysis; D005139:Eyeglasses; D005260:Female; D006801:Humans; D007198:Indians, North American; D008297:Male; D018803:Models, Economic; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D015351:Vision Screening / Q000191:economics*; D014792:Visual Acuity