title: Outcomes of Sequential Glaucoma Drainage Implants in Refractory Glaucoma.
abstract: OBJECTIVE
  To describe the outcomes of eyes that have undergone a second glaucoma drainage implant (GDI) surgery.
  
  
  METHODS
  A retrospective review of eyes that underwent a second GDI surgery from 2006 to 2013 was conducted. Primary outcome measures included intraocular pressure (IOP) reduction and success rates. Secondary outcome measures included glaucoma medication use, visual acuity, and number of reoperations. Success was defined as 6 ≤ IOP ≤ 21 with at least 20% IOP reduction, and no increase in the number of glaucoma medications from baseline at 3 months of follow-up or more.
  
  
  RESULTS
  Sixty-five eyes (63 patients) had a mean follow-up of 22.4 ± 19.9 months. The most frequently placed second GDIs were an Ahmed FP7 (49%) or a Baerveldt 250 (26%) in the inferotemporal (46%) or inferonasal (35%) quadrant. At 3-year follow-up, IOP was reduced from 25.8 ± 7.7 to 17.4 ± 9.9 mm Hg (P = 0.004) and the number of glaucoma medications decreased from 3.6 ± 1.2 to 2.5 ± 1.4 (P = 0.01) compared with baseline. The median time to failure was 24.7 ± 5.8 months. There was no significant difference in failure rates for type of sequential GDI (P = 0.80) or plate location (P = 0.34). There was no significant difference in visual acuity between baseline and 3-year follow-up (P = 1.0). The most common postoperative complication was corneal edema (n = 9, 14%).
  
  
  CONCLUSIONS
  Most eyes undergoing a second GDI achieve adequate IOP control with fewer antiglaucoma medications. Failure rates were similar regardless of quadrant selection or GDI type.
authors.affiliation: *Glaucoma Research Center, Wills Eye Hospital †Department of Pharmacology and Experimental Therapeutics, Division of Biostatistics, Thomas Jefferson University, Philadelphia, PA.
authors.forename: Wanda D
authors.initials: WD
authors.lastname: Hu
authors.forename: Marlene R
authors.initials: MR
authors.lastname: Moster
authors.forename: Cindy X
authors.initials: CX
authors.lastname: Zheng
authors.forename: Naryan
authors.initials: N
authors.lastname: Sabherwal
authors.forename: Edward
authors.initials: E
authors.lastname: Pequignot
authors.forename: Victor
authors.initials: V
authors.lastname: Cvintal
authors.forename: Feyzahan
authors.initials: F
authors.lastname: Ekici
authors.forename: Michael
authors.initials: M
authors.lastname: Waisbourd
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D005901:Glaucoma / Q000503:physiopathology / Q000601:surgery*; D020327:Glaucoma Drainage Implants; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D015814:Ocular Hypotension / Q000601:surgery; D011183:Postoperative Complications; D019919:Prosthesis Implantation; D012086:Reoperation; D012189:Retrospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology