title: Surgical outcomes of external dacryocystorhinostomy and risk factors for functional failure: a 10-year experience.
abstract: OBJECTIVE
  To analyze the surgical outcomes of external dacryocystorhinostomy (DCR) and the risk factors associated with functional failure.
  
  
  METHODS
  We reviewed the medical records of 769 patients who underwent external DCR for primary lacrimal drainage obstruction between 2005 and 2014. Recorded data included intraoperative anatomical findings, postoperative diagnosis, and surgical outcomes. We performed univariate and multivariate analyses to identify risk factors for functional failure.
  
  
  RESULTS
  Of the 769 cases, primary nasolacrimal duct obstruction (NLDO) was diagnosed in 457 cases; common canalicular obstruction in 228 cases; and canalicular obstruction in 84 cases. Anatomical success was achieved in 98.8% (760/769) and functional success in 81.9% (630/769) of the cases. An analysis of 760 anatomically successful DCRs showed that common canalicular obstruction (OR=1.752, P=0.014) and canalicular obstruction (OR=2.058, P=0.015) were independent risk factors for functional failure. In a subgroup analysis of patients with primary NLDO, patients with a small lacrimal sac had a significantly higher risk of functional failure (OR=2.500, P=0.018).
  
  
  CONCLUSIONS
  The overall surgical outcomes of external DCR were favorable in this case series. Site of obstruction was an important risk factor for functional failure in cases with primary lacrimal drainage obstruction. A small lacrimal sac was also found to be a risk factor for functional failure in cases with primary NLDO.
authors.affiliation: Department of Ophthalmology, Hallym University Sacred Heart Hospital, Anyang, Korea.
authors.forename: M J
authors.initials: MJ
authors.lastname: Lee
authors.affiliation: Department of Ophthalmology, Seoul National University Hospital, Seoul, Korea.
authors.forename: S I
authors.initials: SI
authors.lastname: Khwarg
authors.affiliation: SW Bright Eye Clinic, Pocheon, Korea.
authors.forename: I H
authors.initials: IH
authors.lastname: Kim
authors.affiliation: Department of Ophthalmology, Korean Armed Forces Capital Hospital, Seongnam, Korea.
authors.forename: J H
authors.initials: JH
authors.lastname: Choi
authors.affiliation: Department of Ophthalmology, Kangdong Sacred Heart Hospital, Hallym University Medical Center, Seoul, Korea.
authors.forename: Y J
authors.initials: YJ
authors.lastname: Choi
authors.affiliation: Department of Ophthalmology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: N
authors.initials: N
authors.lastname: Kim
authors.affiliation: Department of Ophthalmology, Seoul Metropolitan Government Seoul National University, Boramae Medical Center, Seoul, Korea.
authors.forename: H-K
authors.initials: HK
authors.lastname: Choung
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D003608:Dacryocystorhinostomy / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D005544:Forecasting; D006801:Humans; D015994:Incidence; D007767:Lacrimal Duct Obstruction / Q000175:diagnosis / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009301:Nasolacrimal Duct / Q000000981:diagnostic imaging* / Q000601:surgery; D011183:Postoperative Complications / Q000453:epidemiology*; D011877:Radionuclide Imaging; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D055815:Young Adult