title: Field evaluation of the Welch Allyn SureSight vision screener: incorporating the vision in preschoolers study recommendations.
abstract: BACKGROUND
  The prospective Vision in Preschoolers (VIP) study evaluated 11 methods of screening and proposed referral criteria for the Welch Allyn SureSight(trade mark) Vision Screener with 90% and 94% specificity. The SureSight had a higher sensitivity than most other screening techniques when these criteria were applied. We evaluated the usefulness of these criteria in a field study of healthy preschool children.
  
  
  METHODS
  The SureSight software was altered to recommend referral using the VIP referral criteria with 90% specificity. Lions Club volunteers screened preschool children throughout Tennessee. Referred children underwent comprehensive eye examinations with cycloplegic refraction. Examination failure criteria were based upon published standards. Reanalysis using the 94% specificity criteria was then performed. Outcomes included referral rate and positive predictive value.
  
  
  RESULTS
  The SureSight was used to screen 4,733 children, and screening was successful in 99.7% of children. The referral rate using the 90% specificity criteria was 12.2%. Most children (73%) were referred for suspected astigmatism. The positive predictive value was 30%. Using the 94% specificity criteria from the VIP study decreased the referral rate to 7.9% and substantially decreased over referral for suspected astigmatism; however, several anisometropes went undetected. Higher specificity was achieved by raising astigmatism referral criteria to 2.2 diopters while leaving the anisometropia criteria unchanged.
  
  
  CONCLUSIONS
  The SureSight can be used successfully for preschool screening in the field provided that criteria with high specificity are incorporated into the instrument's software program. Higher rates of positive predictive value can be achieved without jeopardizing sensitivity by raising astigmatism referral criteria to 2.2 diopters.
authors.affiliation: Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
authors.forename: Ashley J
authors.initials: AJ
authors.lastname: Rowatt
authors.forename: Sean P
authors.initials: SP
authors.lastname: Donahue
authors.forename: Colin
authors.initials: C
authors.lastname: Crosby
authors.forename: Alissa Craft
authors.initials: AC
authors.lastname: Hudson
authors.forename: Sylvia
authors.initials: S
authors.lastname: Simon
authors.forename: Kathy
authors.initials: K
authors.lastname: Emmons
mesh_terms: D000550:Amblyopia / Q000175:diagnosis*; D002648:Child; D002675:Child, Preschool; D005189:False Positive Reactions; D005260:Female; D017408:Guidelines as Topic; D006801:Humans; D007223:Infant; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012017:Referral and Consultation; D012030:Refractive Errors / Q000175:diagnosis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015351:Vision Screening / Q000295:instrumentation* / Q000379:methods