title: Clinical experience with a novel glaucoma drainage implant.
abstract: OBJECTIVE
  To retrospectively evaluate the safety and efficacy of an Ahmed glaucoma valve (AGV) modified with a polyethylene shell (M4) to reduce the fibrotic reaction around the drainage plate compared with the S2 and FP7 models in patients with glaucoma.
  
  
  METHODS
  The medical records of patients who underwent implantation of the AGV FP7, S2, and M4 were reviewed. The primary outcome measure was cumulative probability of success, defined as an intraocular pressure (IOP) between 5 and 18 mm Hg and >20% reduction of IOP without loss of light perception, need for additional IOP-lowering surgical procedures, or removal of AGV.
  
  
  RESULTS
  Seventy-six, 38, and 40 eyes received the FP7, S2, and M4 with a mean follow-up time of 578±157, 662±186, and 504±158 days, respectively. The mean IOP was reduced from 31.0±10.6 to 13.9±5.5 mm Hg in the FP7 group, 33.5±12.1 to 15.8±8.1 mm Hg in the S2 group, and 27.0±12.0 to 15.0±4.0 mm Hg in the M4 group at 1 year (P=0.31). At 1 year, the cumulative probability of success was 70%, 66%, and 80% and at 18 months, 61%, 53%, and 52% in the FP7, S2, and M4 groups, respectively (P=0.99). Complications were similar among groups.
  
  
  CONCLUSIONS
  No significant difference was observed between the AGV M4, FP7, and S2 at 1 year. Additional follow-up is required to determine its long-term safety profile and efficacy.
authors.affiliation: *Duke Eye Center †Department of Plastic Surgery, Duke University, Durham, NC.
authors.forename: James
authors.initials: J
authors.lastname: Kim
authors.forename: R Rand
authors.initials: RR
authors.lastname: Allingham
authors.forename: Jason
authors.initials: J
authors.lastname: Hall
authors.forename: Bruce
authors.initials: B
authors.lastname: Klitzman
authors.forename: Sandra
authors.initials: S
authors.lastname: Stinnett
authors.forename: Sanjay
authors.initials: S
authors.lastname: Asrani
mesh_terms: D000368:Aged; D005260:Female; D005901:Glaucoma / Q000503:physiopathology / Q000601:surgery*; D020327:Glaucoma Drainage Implants; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D007431:Intraoperative Complications; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D019919:Prosthesis Implantation; D012189:Retrospective Studies; D014065:Tonometry, Ocular; D016896:Treatment Outcome