title: The effect of developmentally-at-risk status on the reliability of the iScreen® photorefractive device in young children.
abstract: OBJECTIVE
  We evaluated the impact of developmentally-at-risk status on the results of photorefractive screening with iScreen®.
  
  
  METHODS
  We sequentially recruited 169 children (aged 2-5 years) to participate in a blinded, prospective study of a photoscreening device. The principle investigator examined the children after photoscreening. Using established standards for amblyogenic factors, the principle investigator and photoscreen interpreters separately made a determination of "normal" or "needs referral" for each child. Sensitivity, specificity, positive predictive value, and negative predictive value for the photoscreening device were determined.
  
  
  RESULTS
  Overall, sensitivity was 85% with a positive predictive value of 98%, and specificity was 87% with a negative predictive value of 47%. Developmentally-at-risk status in 34 children (three refused imaging) did not reduce sensitivity (89%) or specificity (100%) when compared with 130 children (two refused imaging) who did not have developmentally-at-risk factors (sensitivity = 84% and specificity = 80%).
  
  
  CONCLUSIONS
  The efficacy of photorefractive screening in young children with developmentally-at-risk status is comparable to results found in normal children.
authors.affiliation: Hamilton Eye Institute and Preventive Medicine Department, University of Tennessee Health Science Center, Memphis, Tennessee 38103, USA. nkerr@uthsc.edu
authors.forename: Natalie C
authors.initials: NC
authors.lastname: Kerr
authors.forename: Grant
authors.initials: G
authors.lastname: Somes
authors.forename: Robert W
authors.initials: RW
authors.lastname: Enzenauer
mesh_terms: D000550:Amblyopia / Q000175:diagnosis*; D015858:Anisometropia / Q000175:diagnosis; D001251:Astigmatism / Q000175:diagnosis; D002675:Child, Preschool; D002658:Developmental Disabilities / Q000175:diagnosis*; D004311:Double-Blind Method; D005189:False Positive Reactions; D006801:Humans; D006956:Hyperopia / Q000175:diagnosis; D009216:Myopia / Q000175:diagnosis; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D042261:Retinoscopes; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013285:Strabismus / Q000175:diagnosis; D015351:Vision Screening / Q000295:instrumentation*