title: Glaucoma drainage device surgery after vitreoretinal surgery: incidence and risk factors.
abstract: OBJECTIVE
  The initial success of vitreoretinal surgery can be annihilated by an acceleration of preexisting glaucoma or the development of secondary glaucoma. Aim of this study was to determine the incidence of and risk factors for medically uncontrollable glaucoma after vitreoretinal surgery.
  
  
  METHODS
  Case-control study amongst patients who underwent vitreoretinal surgery at the University Medical Center Groningen between 1991 and 2011 (in total 14,942 interventions). Cases were all patients who received a glaucoma drainage device after vitreoretinal surgery. Controls were a subset of the patients who underwent vitreoretinal surgery without a subsequent drainage device. Cases and controls were matched (three controls per case) with regard to the year of the (first) vitreoretinal intervention. The incidence rate was calculated from the number of cases and the number of person-years corresponding to all vitreoretinal interventions performed in the study period. Risk factors were analysed with logistic regression.
  
  
  RESULTS
  Ninety-five cases were identified after a follow-up of 101,961 person-years (one per 1000 person-years). Cases were younger (p = 0.017), were more often men (p = 0.035), underwent more interventions (p < 0.001) or were treated with silicone oil (p = 0.021), had a higher intra-ocular pressure 1 week after the intervention (p < 0.001) and had more often a history of glaucoma or ocular hypertension (p < 0.001).
  
  
  CONCLUSIONS
  Glaucoma after vitreoretinal surgery that requires a glaucoma drainage device is not very common and patients who need a device differ from those who do not. This gives the opportunity to monitor certain subgroups more closely.
authors.affiliation: Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Margriet M
authors.initials: MM
authors.lastname: de Vries
authors.affiliation: Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Rogier P H M
authors.initials: RP
authors.lastname: Müskens
authors.affiliation: Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Victor W
authors.initials: VW
authors.lastname: Renardel de Lavalette
authors.affiliation: Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Johanna M M
authors.initials: JM
authors.lastname: Hooymans
authors.affiliation: Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.|Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Nomdo M
authors.initials: NM
authors.lastname: Jansonius
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D005901:Glaucoma / Q000453:epidemiology* / Q000601:surgery*; D020327:Glaucoma Drainage Implants / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D019919:Prosthesis Implantation / Q000706:statistics & numerical data*; D012307:Risk Factors; D057586:Vitreoretinal Surgery / Q000009:adverse effects*
keywords: Baerveldt; glaucoma; retinal detachment; scleral buckling; secondary glaucoma; vitrectomy