title: Risk factors for exposure of glaucoma drainage devices: a retrospective observational study.
abstract: OBJECTIVE
  The purpose of this study was to identify risk factors for exposure of glaucoma drainage devices (GDD).
  
  
  METHODS
  This retrospective, observational study was conducted in the eye clinic of an academic medical centre.
  
  
  METHODS
  Participants included 1073 consecutive adults who underwent GDD surgery between 1 January 2005 and 1 January 2011. Participants were included if chart review indicated GDD surgery during the study period and excluded if at least 12 months of clinical follow-up was not available in the medical record.
  
  
  METHODS
  The primary outcome measure was exposure of the GDD occurring at least 1 month after implant surgery. The characteristics of participants who experienced exposure of the implant were compared to the characteristics of participants who did not experience exposure.
  
  
  RESULTS
  Of the 1073 participants having undergone GDD surgery, 67 experienced exposure of the device. Neither the type of GDD, type of patch graft (eye bank sclera, Tutoplast sclera and Tutoplast pericardium), surgeon, location of GDD, number of GDD previously implanted into the eye, nor history of diabetes or uveitis were associated with likelihood of exposure. Women were more likely than men to experience exposure of the GDD (OR 2.004 (95% CI1.170 to 3.431)) in both univariable (p=0.011) and multivariable (p=0.013) analyses. In survival analysis, exposure of the GDD occurred earlier for women than for men (58 vs 61 months; p=0.024).White race (vs black) was also associated with increased risk of GDD exposure (OR 1.693 (95% CI 1.011 to 2.833)) in univariable (p=0.044) and multivariable (p=0.046) analyses.
  
  
  CONCLUSIONS
  Women are two times more likely to experience GDD exposure than men, independent of age. White race is also a risk factor for exposure.
authors.affiliation: Durham VA Medical Center, Health Services Research & Development, Durham, North Carolina, USA.
authors.forename: Kelly W
authors.initials: KW
authors.lastname: Muir
authors.forename: Annie
authors.initials: A
authors.lastname: Lim
authors.forename: Sandra
authors.initials: S
authors.lastname: Stinnett
authors.forename: Anthony
authors.initials: A
authors.lastname: Kuo
authors.forename: Henry
authors.initials: H
authors.lastname: Tseng
authors.forename: Molly M
authors.initials: MM
authors.lastname: Walsh
mesh_terms: D000368:Aged; D005260:Female; D020327:Glaucoma Drainage Implants / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology; D012189:Retrospective Studies; D012307:Risk Factors