title: Morphometric Evaluation of Bony Nasolacrimal Canal in a Caucasian Population with Primary Acquired Nasolacrimal Duct Obstruction: A Multidetector Computed Tomography Study.
abstract: OBJECTIVE
  The bony nasolacrimal duct (BNLD) morphology as a contributory factor in primary acquired nasolacrimal duct obstruction (PANDO) is still controversial. The objectives of this study were to evaluate the morphometric differences of BNLDs in unilateral PANDO patients between PANDO and non-PANDO sides, as compared with the control group using multidetector computed tomography (CT).
  
  
  METHODS
  Bilateral BNLDs in 39 unilateral PANDO patients and 36 control subjects were retrospectively reviewed. CT images with 0.5-mm thickness were obtained with a 64-slice scanner. The length, volume, coronal orientation type, sagittal orientation angle of BNLD, and relative lacrimal sac-BNLD angle were assessed. The entrance, minimum and distal end transverse diameters (TD) of BNLD was investigated.
  
  
  RESULTS
  The mean minimum and distal end BNLD TDs measurements were significantly narrower in PANDO patients, both in PANDO and non-PANDO sides, as compared with the control group (p < 0.001 and p = 0.040, respectively); however, there were no significant differences between PANDO and non-PANDO sides within PANDO patients. The length, entrance TD, volume, coronal orientation type, sagittal orientation angle of BNLD, and relative lacrimal sac-BNLD angle were not significantly different between PANDO patients and control subjects, as well as between PANDO and non-PANDO sides within PANDO patients.
  
  
  CONCLUSIONS
  The narrow mean minimum and distal end BNLD TD in PANDO patients, in both PANDO and non-PANDO sides, may be associated with PANDO development. The lack of difference between PANDO and non-PANDO sides within PANDO patients and some overlap between PANDO patients and control subjects suggest that narrow BNLD is not the sole factor.
authors.affiliation: Department of Radiology, Balikesir University School of Medicine, Balikesir 10145, Turkey.
authors.forename: Erdogan
authors.initials: E
authors.lastname: Bulbul
authors.affiliation: Department of Ophthalmology, Balikesir University School of Medicine, Balikesir 10145, Turkey.
authors.forename: Alper
authors.initials: A
authors.lastname: Yazici
authors.affiliation: Department of Radiology, Balikesir University School of Medicine, Balikesir 10145, Turkey.
authors.forename: Bahar
authors.initials: B
authors.lastname: Yanik
authors.affiliation: Department of Otolaryngology, Balikesir University School of Medicine, Balikesir 10145, Turkey.
authors.forename: Hasmet
authors.initials: H
authors.lastname: Yazici
authors.affiliation: Department of Radiology, Balikesir University School of Medicine, Balikesir 10145, Turkey.
authors.forename: Gulen
authors.initials: G
authors.lastname: Demirpolat
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007767:Lacrimal Duct Obstruction / Q000175:diagnosis / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D009301:Nasolacrimal Duct / Q000000981:diagnostic imaging*; D012189:Retrospective Studies
keywords: Bony nasolacrimal duct; Computed tomography; Nasolacrimal duct obstruction