Risk factors for exposure of glaucoma drainage devices: a retrospective observational study

OBJECTIVES: The purpose of this study was to identify risk factors for exposure of glaucoma drainage devices (GDD). SETTING: This retrospective, observational study was conducted in the eye clinic of an academic medical centre. PARTICIPANTS: 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. PRIMARY OUTCOME MEASURE: 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.