title: The Ahmed glaucoma valve in neovascular glaucoma (An AOS Thesis).
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) > or =6 mm Hg and < or =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 = .550). At last follow-up, mean IOP was 16.2 +/- 5.2 mm Hg and 15.5 +/- 12.5 mm Hg (P = .115) in control and neovascular glaucoma patients, respectively. Life-table analysis showed a significantly lower success for neovascular glaucoma patients compared with controls (P = .0096), with success at 1 year of 89.2% and 73.1%, at 2 years of 81.8% and 61.9%, and at 5 years of 81.8% and 20.6% for control and neovascular glaucoma eyes, respectively. Cox proportional hazards regression analysis showed neovascular glaucoma as a risk factor for surgical failure (odds ratio, 5.384, 95% CI, 1.22-23.84, P = .027). Although IOP control and complications were comparable between the two groups, visual outcomes were worse in neovascular glaucoma patients, with 9 eyes (23.7%) with neovascular glaucoma compared with no controls losing light perception vision (P = .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 mean IOP with drainage implants, visual outcomes may be poor, possibly due to progression of underlying disease.
authors.affiliation: Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, USA.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Netland
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 / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007429:Intraocular Pressure; D053208:Kaplan-Meier Estimate; D015993:Life Tables; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D016016:Proportional Hazards Models; D019919:Prosthesis Implantation / Q000009:adverse effects / Q000592:standards*; D012189:Retrospective Studies; D012307:Risk Factors; D017211:Treatment Failure; D014786:Vision Disorders / Q000209:etiology; D055815:Young Adult