Ahmed Versus Baerveldt Comparison Study
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- University of Miami
- Enrollment
- 276
- Locations
- 2
- Primary Endpoint
- Intraocular Pressure
Study Overview
Brief Summary
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.
Detailed Description
Background and Significance
Aqueous shunt devices have traditionally been reserved for treatment of only the most refractory glaucomas. However, more recent studies have reported favorable results in comparison with trabeculectomy in medically uncontrolled glaucomas at lower risk of filtration failure. Consequently, aqueous shunt devices have been used increasingly in glaucoma drainage surgery.
There are two principal designs of implant in common use, the Ahmed glaucoma valve implant (New World Medical, Los Ranchos, CA, USA and the Baerveldt implant (Advanced Medical Optics, Santa Ana, CA, USA).
Having both evolved from the Molteno, the Ahmed and Baerveldt devices have in common a tube portion that drains aqueous humor from the anterior chamber to a plate that is implanted on the equatorial sclera. The size of plate determines the surface area of the drainage bleb.
The Ahmed and Baerveldt implants differ in two major respects. Firstly, the plate surface area of the Baerveldt 350 implant is almost double that of the Ahmed (185 mm2). Secondly, the Ahmed has a flow-restrictor that limits early hypotony without the need for additional external ligation.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Treatment
- Masking
- None
Eligibility Criteria
- Ages
- 18 Years to 85 Years (Adult, Older Adult)
- Sex
- 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.
Outcomes
Primary Outcomes
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 Outcomes
- Visual Acuity(5 years)
Investigators
Donald L. Budenz
Study Chairman
University of North Carolina, Chapel Hill