title: Preverbal photoscreening for amblyogenic factors and outcomes in amblyopia treatment: early objective screening and visual acuities.
abstract: BACKGROUND
  Previous studies have suggested that infant photoscreening yields better results than visual acuity screening in preschool-aged children. With conventional vision screening, the patient must be able to provide monocular visual acuity cooperation, whereas objective screening for amblyogenic factors can be done at much younger ages.
  
  
  METHODS
  From February 1996 through February 2006, Alaska Blind Child Discovery photoscreened 21,367 rural and urban Alaskan children through grade 2, with an 82% positive predictive value (ie, true number of those referred); 6.9% were referred for a complete eye examination and treatment. All "referred" interpreted images for children younger than 48 months who were then followed up and treated for more than 2 years were reviewed to determine whether treatment was successful.
  
  
  RESULTS
  Of 411 "positive" screening photos from children younger than 4 years, 94 patients had more than 2 years follow-up. The 36 children photoscreened before age 2 years had a mean treated visual acuity of 0.17 logarithm of the minimum angle of resolution (logMAR), which was significantly better than that of 58 children screened between ages 25 and 48 months (mean, 0.26 logMAR). Despite similar levels of amblyogenic risk factors, the proportion of children failing to reach a visual acuity of 20/40 was significantly less among those screened before age 2 years (5%) than in those screened from ages older than 2.0 years and younger than 4.0 years (17%).
  
  
  CONCLUSIONS
  Very early photoscreening yields better visual outcomes in amblyopia treatment compared with later photoscreening in preschool-aged children.
authors.affiliation: Division of Pediatric Ophthalmology and Strabismus, Ophthalmic Associates, Anchorage, Alaska 99501-2242, USA.
authors.forename: Valerie G
authors.initials: VG
authors.lastname: Kirk
authors.forename: Michelle M
authors.initials: MM
authors.lastname: Clausen
authors.forename: M Diane
authors.initials: MD
authors.lastname: Armitage
authors.forename: Robert W
authors.initials: RW
authors.lastname: Arnold
mesh_terms: D000413:Alaska; D000550:Amblyopia / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy*; D002648:Child; D002675:Child, Preschool; D005189:False Positive Reactions; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D011237:Predictive Value of Tests; D012307:Risk Factors; D012424:Rural Population; D016896:Treatment Outcome; D014505:Urban Population; D015351:Vision Screening; D014792:Visual Acuity / Q000502:physiology*