The Ahmed Baerveldt Comparison Study methodology, baseline patient characteristics, and intraoperative complications

Ophthalmology. 2011 Mar;118(3):435-42. doi: 10.1016/j.ophtha.2010.07.015. Epub 2010 Oct 8.


Purpose: The Ahmed Baerveldt Comparison (ABC) Study compares the long-term outcomes and complications of the Ahmed glaucoma valve (AGV; model FP7; New World Medical, Los Ranchos, CA) and the Baerveldt glaucoma implant (BGI; model 101-350; Abbott Medical Optics, Abbott Park, IL).

Design: Multicenter, randomized, controlled clinical trial.

Participants: Two hundred seventy-six glaucoma patients at 16 clinical centers worldwide who were 18 to 85 years of age with inadequately controlled intraocular pressure (IOP; ≥18 mmHg) in whom placement of an aqueous shunt was planned.

Methods: Study patients were randomized to undergo implantation of an AGV or a BGI.

Main outcome measures: Failure, defined as IOP >21 mmHg or not reduced by 20% less than baseline or IOP ≤5 mmHg (2 consecutive visits after 3 months), additional glaucoma surgery, removal of the implant, or loss of light perception vision.

Results: A total of 276 patients were enrolled between October 2006 and April 2008, including 143 in the AGV group and 133 in the BGI group. The mean age±standard deviation (SD) of patients enrolled was 63±14 years, and 52% were male. The mean baseline IOP±SD was 31.5±11.8 mmHg. Except for a 13% higher prevalence of hypertension in the AGV group, no significant differences in baseline demographic or ocular characteristics were observed between the study groups. Intraoperative complications occurred in 11 (8%) patients in the AGV group and in 16 (12%) patients in the BGI group (P = 0.31).

Conclusions: The ABC Study should yield valuable prospective data comparing 2 commonly used aqueous shunts in clinical practice.

Publication types

  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Aqueous Humor / metabolism
  • Eye Movements / physiology
  • Female
  • Follow-Up Studies
  • Glaucoma / physiopathology
  • Glaucoma / surgery*
  • Glaucoma Drainage Implants*
  • Gonioscopy
  • Humans
  • Intraocular Pressure / physiology
  • Intraoperative Complications*
  • Male
  • Middle Aged
  • Prosthesis Implantation*
  • Refraction, Ocular / physiology
  • Tonometry, Ocular
  • Treatment Outcome
  • Visual Acuity / physiology
  • Visual Field Tests
  • Young Adult