title: Amblyopia risk factors in infants with congenital nasolacrimal duct obstruction.
abstract: OBJECTIVE
  This study aims to report the prevalence of amblyopia risk factors in patients with congenital nasolacrimal duct obstructions.
  
  
  METHODS
  We recruited patients who were treated for congenital nasolacrimal duct obstruction from April 2007 to December 2011 at Korea University Ansan Hospital. We evaluated visual acuity and refraction, performed strabismus test and slit-lamp examination, and assessed marginal reflex distance 1 (MRD1) to rule out amblyopia risk factors.
  
  
  RESULTS
  We examined 26 children among 115 patients. Ten patients underwent probing procedure and 16 underwent Monoka stent intubation. Nine (35%) patients showed amblyopia risk factors, which occurred in the same eye as the congenital nasolacrimal duct obstruction in 8 (89%) patients. Seven out of 9 patients had refractive error alone, and 2 patients had both refractive error and strabismus. One (11%) had anisometropia, 2 (22%) had hyperopia, and 8 (89%) had astigmatism.
  
  
  CONCLUSIONS
  Children with congenital nasolacrimal duct obstruction had a higher prevalence of amblyopia risk factors than children in the general population. Children with congenital nasolacrimal duct obstruction require special attention and treatments for refractive error. We recommend early treatment, such as probing or intubation, for congenital nasolacrimal duct obstruction.
authors.affiliation: Department of Ophthalmology, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jung Wan
authors.initials: JW
authors.lastname: Kim
authors.forename: Hwa
authors.initials: H
authors.lastname: Lee
authors.forename: Minwook
authors.initials: M
authors.lastname: Chang
authors.forename: Minsoo
authors.initials: M
authors.lastname: Park
authors.forename: Tae Soo
authors.initials: TS
authors.lastname: Lee
authors.forename: Sehyun
authors.initials: S
authors.lastname: Baek
mesh_terms: D000550:Amblyopia / Q000453:epidemiology / Q000209:etiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007767:Lacrimal Duct Obstruction / Q000150:complications / Q000151:congenital; D008297:Male; D015995:Prevalence; D012030:Refractive Errors / Q000150:complications; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D013285:Strabismus / Q000150:complications; D014792:Visual Acuity / Q000502:physiology