title: Congenital nasolacrimal duct obstruction: delineation of anatomic abnormalities with 3-dimensional reconstruction.
abstract: OBJECTIVE
  To characterize anatomical abnormalities of the distal nasolacrimal duct (NLD) in children with congenital obstruction using high-resolution computed tomographic imaging.
  
  
  METHODS
  The anatomy of the bone and soft tissue of the NLD and the postductal anatomy of the inferior meatus in 6 children with a wide spectrum of NLD obstructions were imaged by computed tomographic scans and then reconstructed in a 3-dimensional viewer. Images were taken from prior axial (5 children) or coronal (1 child) computed tomographic facial scans at 0.625- or 1.25-mm mm resolution, respectively.
  
  
  RESULTS
  The axial computed tomographic images and 3-dimensional reconstructions showed bony obstructions of the distal NLD in 3 children, membranous obstructions of the distal NLD in 1 child, and a postductal obstruction in the inferior meatus in 1 child. One child had a combined soft tissue obstruction of the NLD and post-NLD obstruction.
  
  
  CONCLUSIONS
  This study provides anatomic evidence of a bony or membranous obstruction at the distal portion of the NLD or of a postductal obstruction at the inferior meatus in children with congenital NLD obstruction.
authors.affiliation: Roger Johnson Clinical Vision Laboratory, Seattle Children’s Hospital, and Department of Ophthalmology, University of Washington Medical Center, Seattle, WA 98105, USA. avery.weiss@seattlechildrens.org
authors.forename: Avery H
authors.initials: AH
authors.lastname: Weiss
authors.forename: Francine
authors.initials: F
authors.lastname: Baran
authors.forename: John
authors.initials: J
authors.lastname: Kelly
mesh_terms: D002675:Child, Preschool; D005260:Female; D006257:Head / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007223:Infant; D007231:Infant, Newborn; D007767:Lacrimal Duct Obstruction / Q000151:congenital* / Q000000981:diagnostic imaging; D008297:Male; D009301:Nasolacrimal Duct / Q000002:abnormalities* / Q000000981:diagnostic imaging; D009915:Orbit / Q000000981:diagnostic imaging; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed