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Ahmed Versus Baerveldt Comparison Study (ABC)

This study has been completed.
National Eye Institute (NEI)
Research to Prevent Blindness
Information provided by (Responsible Party):
Donald L. Budenz, University of North Carolina, Chapel Hill Identifier:
First received: September 13, 2006
Last updated: July 25, 2015
Last verified: July 2015
The objective of this study is to compare the long-term safety and efficacy of the Ahmed and the Baerveldt implants in patients who are undergoing aqueous shunt implant surgery for glaucoma. One eye of eligible patients will be randomized. Outcome measures include intraocular pressure, visual acuity, visual field, number of glaucoma medications, glaucoma reoperations, and complications, including suprachoroidal hemorrhage, endophthalmitis, choroidal effusion, diplopia, corneal edema, and shunt/tube erosion.

Condition Intervention
Device: Ahmed implant
Device: Baerveldt implant

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Ahmed Versus Baerveldt Comparison Study

Resource links provided by NLM:

Further study details as provided by Donald L. Budenz, University of North Carolina, Chapel Hill:

Primary Outcome Measures:
  • Intraocular Pressure [ Time Frame: 5 years ]
    intraocular pressure mmHg at 5 years

  • Failure Rate [ Time Frame: 5 years ]
    5-year failure rate measured by Kaplan-Meier, defined as IOP>21 mm Hg or less than a 20% reduction below baseline on 2 consecutive study visits after 3 months, reoperation for glaucoma, loss of light perception, or removal of implant

Secondary Outcome Measures:
  • Visual Acuity [ Time Frame: 5 years ]
    Snellen chart converted to logMAR (smaller logMAR values indicate better visual acuity logMar of 0 is Snellen 20/20; logMAR of 20/200 is 1.0)

Enrollment: 276
Study Start Date: November 2005
Study Completion Date: October 2014
Primary Completion Date: December 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Ahmed implant,1
Ahmed glaucoma drainage implant for intraocular pressure control
Device: Ahmed implant
placement of glaucoma drainage device to control intraocular pressure
Other Name: Ahmed fp7
Active Comparator: Baerveldt implant
Baerveldt glaucoma drainage implant for intraocular pressure control
Device: Baerveldt implant
placement of glaucoma drainage device to control intraocular press
Other Name: Baerveldt 350

  Show Detailed Description


Ages Eligible for Study:   18 Years to 85 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Age 18 to 85 years, inclusive.
  • Glaucoma that is inadequately controlled on tolerated medical therapy with intraocular pressure greater than or equal to 18 mm Hg.
  • Glaucoma drainage implant as planned surgical procedure.
  • POAG with previous failed trabeculectomy or other intraocular surgery.
  • Secondary glaucoma with or without previous intraocular surgery

Exclusion Criteria:

  • Unwilling or unable to give consent or unwilling to accept randomization.
  • Patient out of area and potentially unavailable for follow-up visits
  • No light perception.
  • Uveitis secondary to Juvenile Idiopathic Arthritis
  • Previous cyclodestructive procedure or previous aqueous shunt device implanted in the same eye.
  • Supero-temporal buckling or other external impediment to supero-temporal aqueous shunt implantation.
  • Silicone oil-filled eyes or sufficient residual intraocular silicone oil to preclude supero-temporal aqueous shunt implantation.
  • Vitreous sufficient to require a vitrectomy present in the anterior chamber at the time of surgery.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00376363

United States, Florida
University of Miami, Bascom Palmer Eye Institute
Miami, Florida, United States, 33136
Sponsors and Collaborators
University of Miami
National Eye Institute (NEI)
Research to Prevent Blindness
Principal Investigator: Donald L Budenz, M.D.,M.P.H. University of North Carolina
Principal Investigator: Keith Barton, M.D. Moorfields Eye Hospital NHS Foundation Trust
Principal Investigator: William J Feuer, M.S. University of Miami
  More Information


Responsible Party: Donald L. Budenz, Study Chairman, University of North Carolina, Chapel Hill Identifier: NCT00376363     History of Changes
Other Study ID Numbers: 20057138
P30EY014801 ( US NIH Grant/Contract Award Number )
Study First Received: September 13, 2006
Results First Received: May 17, 2015
Last Updated: July 25, 2015

Keywords provided by Donald L. Budenz, University of North Carolina, Chapel Hill:
Ahmed implant
Baerveldt implant

Additional relevant MeSH terms:
Ocular Hypertension
Eye Diseases processed this record on May 25, 2017