title: Evaluation of the iScreen digital screening system for amblyogenic factors.
abstract: BACKGROUND
  A digital photoscreener, the iScreen screening system, is now available to detect amblyogenic factors. We carried out a prospective study to evaluate the accuracy of the device in detecting anisometropia, significant refractive error, strabismus and opacities of the ocular media.
  
  
  METHODS
  A total of 449 consecutive patients (median age 7 years) from a private pediatric ophthalmology practice underwent screening with the iScreen photoscreener operated by a minimally trained technician. The results were compared to the masked clinical examination of a pediatric ophthalmologist.
  
  
  RESULTS
  The iScreen device had a sensitivity of 92.4%, specificity of 89.1%, positive predictive value of 94.1% and false-negative rate of 13.8%. Of the 21 patients with a false-negative result, 12 had myopia of less than -1.50 dioptres. High hyperopia was missed in two patients, high astigmatism in one, unequal cylindrical error in one and strabismus in five.
  
  
  CONCLUSIONS
  The iScreen digital photoscreener produced accurate and timely screening for potentially amblyogenic defects in the study population.
authors.affiliation: Department of Ophthalmology, University of British Columbia, Vancouver.
authors.forename: R A
authors.initials: RA
authors.lastname: Kennedy
authors.forename: D E
authors.initials: DE
authors.lastname: Thomas
mesh_terms: D000293:Adolescent; D000550:Amblyopia / Q000175:diagnosis* / Q000209:etiology; D002386:Cataract / Q000150:complications; D002648:Child; D002675:Child, Preschool; D016288:Computer Terminals; D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation*; D001330:Electronic Data Processing / Q000295:instrumentation*; D006801:Humans; D011446:Prospective Studies; D012030:Refractive Errors / Q000150:complications; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013285:Strabismus / Q000150:complications; D014792:Visual Acuity