title: The Ahmed Glaucoma Valve in patients with and without neovascular glaucoma.
abstract: OBJECTIVE
  To evaluate the results of Ahmed Glaucoma Valve surgery in neovascular glaucoma and control patients.
  
  
  METHODS
  In this retrospective comparative study, we reviewed 76 eyes of 76 patients, comparing the surgical outcomes in control patients (N=38) to matched neovascular glaucoma patients (N=38). Success was defined as intraocular pressure (IOP) ≥6 mm Hg and ≤21 mm Hg, without further glaucoma surgery, and without loss of light perception.
  
  
  RESULTS
  Average follow-up for control and neovascular glaucoma patients was 18.4 and 17.4 months, respectively (P=0.550). The mean IOPs were 17.9±8.4 mm Hg and 16.5±15.8 mm Hg at 1-year (P=0.150), and 18.4±11.2 mm Hg and 9.9±6.3 mm Hg at 2 years (P=0.057) in controls and eyes with neovascular glaucoma, respectively. Life-table analysis showed a significantly lower success for neovascular glaucoma patients compared with controls (P=0.0096), with success at 1 year=89.2% and 73.1%, 2 years=81.8% and 61.9%, and 5 years=81.8% and 20.6% for control and neovascular glaucoma eyes, respectively. Cox proportional hazard regression analysis showed neovascular glaucoma as a risk factor for surgical failure (odds ratio=5.384, 95% CI=1.22-23.84, P=0.027). Although IOP control and complications were comparable between the 2 groups, visual outcomes were worse in neovascular glaucoma patients, with 9 (23.7%) eyes with neovascular glaucoma compared with no controls losing light perception vision (P=0.002). The majority with loss of vision (5 of 9) had successful control of IOP during the postoperative period.
  
  
  CONCLUSIONS
  Neovascular glaucoma patients have greater risk of surgical failure after Ahmed Glaucoma Valve surgery compared with controls. Despite improved IOP with drainage implants, visual outcomes may be poor, probably owing to progression of underlying disease.
authors.affiliation: Department of Ophthalmology, Hamilton Eye Institute, University of Tennessee Health Science Center, Memphis, Tennessee, USA. pnetland@virginia.edu
authors.forename: Peter A
authors.initials: PA
authors.lastname: Netland
authors.forename: Kyoko
authors.initials: K
authors.lastname: Ishida
authors.forename: John W
authors.initials: JW
authors.lastname: Boyle
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D020327:Glaucoma Drainage Implants; D015355:Glaucoma, Neovascular / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D006068:Gonioscopy; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D015993:Life Tables; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D019919:Prosthesis Implantation; D012189:Retrospective Studies; D012307:Risk Factors; D014065:Tonometry, Ocular; D016896:Treatment Outcome; D055815:Young Adult