title: High prevalence of amblyopia risk factors in preverbal children with nasolacrimal duct obstruction.
abstract: OBJECTIVE
  To report the percentage of children under the age of 3 with nasolacrimal duct obstruction (NLDO) and amblyopia risk factors who develop clinical evidence of amblyopia over time.
  
  
  METHODS
  Records of children under 3 years of age presenting to a pediatric oculoplastic specialist with NLDO between January 1, 2001, and August 8, 2009, were retrospectively reviewed to identify those who also had amblyopia risk factors. Amblyopia was diagnosed based on visual acuity and treatment history.
  
  
  RESULTS
  A total of 375 children under the age of 3 had NLDO. Of these, 82 (22%) had amblyopia risk factors, and 70 received a follow-up examination. Average age at first visit was 12 months (1-27 months). In all patients with anisometropia and unilateral NLDO, the side with the NLDO had higher hyperopia. Of the 70 with risk factors, 44 (63%) were later treated for amblyopia: 29 with spectacles alone, 2 with occlusion therapy, 13 with spectacles and occlusion therapy. Six patients required strabismus surgery. In all patients with anisometropia and unilateral NLDO, the side with the NLDO had higher hyperopia.
  
  
  CONCLUSIONS
  The percentage of children identified with amblyopia risk factors who later develop clinical amblyopia was much higher than the 1.6% to 3.6% expected in a cohort of normal children.
authors: Family Eye Group, Vision Science Department, Lancaster, Pennsylvania 17601, USA. NoelleMatta@gmail.com
authors: Noelle S
authors: NS
authors: Matta
authors: David I
authors: DI
authors: Silbert
mesh_terms: D000293:Adolescent; D000550:Amblyopia / Q000453:epidemiology* / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007767:Lacrimal Duct Obstruction / Q000453:epidemiology* / Q000473:pathology*; D008297:Male; D009301:Nasolacrimal Duct / Q000473:pathology*; D015995:Prevalence; D012307:Risk Factors; D013285:Strabismus / Q000453:epidemiology / Q000601:surgery; D014792:Visual Acuity