title: Associated factors of functional failure of external dacryocystorhinostomy.
abstract: OBJECTIVE
  To evaluate the incidence and associated factors of functional failure of anatomically patent external dacryocystorhinostomy (DCR).
  
  
  METHODS
  Prospective, nonrandomized case series.
  
  
  METHODS
  Thirty-four consecutive patients who underwent external DCR at the oculoplasty clinic in the Department of Ophthalmology, Seoul National University Hospital between December 2008 and July 2009.
  
  
  METHODS
  All patients underwent external DCR for primary acquired nasolacrimal duct obstruction. The silicone tubes were removed around 6 months after the DCRs, and patients were examined 1 month after tube removal. Anatomical patency was evaluated by a nasal endoscopic dye test and lacrimal syringing test. Tearing symptoms were evaluated using Munk's scoring system. Patients were divided into 2 groups according to the presence of epiphora symptom; a functional success and functional failure group, and the incidence of functional failure were calculated. Potential associated factors were also compared between 2 groups.
  
  
  RESULTS
  This study involved 50 eyes of 34 patients, and 8 eyes of 6 patients showed significant epiphora in spite of anatomical patency (16% functional failure). We compared associated factors between 42 functionally successful and 8 functionally failed DCRs. Among variables studied, demographic factors and intraoperative surgical findings were not statistically different between the 2 groups. With respect to intranasal endoscopic findings, the shape of the rhinostomy showed significant differences between the 2 groups (p = 0.03, Fisher's exact test). In the functional failure group, there were no flat shape rhinostomies. Three showed alcove shape rhinostomies, and the other 5 showed cavern shape rhinostomies.
  
  
  CONCLUSIONS
  Among anatomically patent DCRs, the incidence of persistent epiphora was 16%. The shape of rhinostomy is a possible associated factor for functional failure after external DCR.
authors: Department of Ophthalmology, Hallym University Sacred Heart Hospital, Anyang.
authors: Min Joung
authors: MJ
authors: Lee
authors: Department of Ophthalmology, Seoul National University Hospital. Electronic address: khwarg@snu.ac.kr.
authors: Sang In
authors: SI
authors: Khwarg
authors: Department of Ophthalmology, Seoul National University Boramae Hospital, Seoul.
authors: Ho-Kyung
authors: HK
authors: Choung
authors: Department of Ophthalmology, Seoul National University Bundang Hospital, Seoungnam, Korea.
authors: Namju
authors: N
authors: Kim
mesh_terms: D003608:Dacryocystorhinostomy; D005260:Female; D006801:Humans; D015994:Incidence; D007767:Lacrimal Duct Obstruction / Q000175:diagnosis / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009301:Nasolacrimal Duct / Q000503:physiopathology / Q000601:surgery*; D011446:Prospective Studies; D012307:Risk Factors; D017211:Treatment Failure