The Ahmed Versus Baerveldt study: one-year treatment outcomes

Objective: To report the 1-year treatment outcomes of the Ahmed Versus Baerveldt (AVB) Study.

Design: Multicenter randomized clinical trial.

Participants: A total of 238 patients were enrolled in the study, including 124 in the Ahmed group and 114 in the Baerveldt group.

Methods: Patients aged 18 years or older with uncontrolled glaucoma refractory to medicinal, laser, and surgical therapy were randomized to undergo implantation of an Ahmed-FP7 valve (New World Medical, Inc., Rancho Cucamonga, CA) or a Baerveldt-350 implant (Abbott Medical Optics, Inc., Santa Ana, CA), to be followed for 5 years.

Main outcome measures: The primary outcome measure was failure, defined as intraocular pressure (IOP) out of target range (5-18 mmHg with ≥ 20% reduction from baseline) for 2 consecutive visits after 3 months, vision-threatening complications, additional glaucoma procedures, or loss of light perception. Secondary outcome measures included IOP, medication use, visual acuity, complications, and interventions.

Results: There were no significant differences in baseline ocular or demographic characteristics between the study groups with the exception of sex. Preoperatively, the study group had a mean IOP of 31.4 ± 10.8 mmHg on a mean of 3.1 ± 1.0 glaucoma medications with a median Snellen acuity of 20/100. The cumulative probability of failure a 1-year was 43% in the Ahmed group and 28% in the Baerveldt group (P = 0.02). The mean IOP at 1 year was 16.5 ± 5.3 mmHg in the Ahmed group and 13.6 ± 4.8 mmHg in the Baerveldt group (P < 0.001). The mean number of glaucoma medications required was 1.6 ± 1.3 in the Ahmed group and 1.2 ± 1.3 in the Baerveldt group (P = 0.03). Visual acuity was similar in both groups at all visits in the first year (P = 0.66). In the first year after surgery, there were a similar number of patients who experienced postoperative complications in the 2 groups (45% Ahmed, 54% Baerveldt, P = 0.19), but a greater number of patients in the Baerveldt group required interventions (26% Ahmed vs. 42% Baerveldt, P = 0.009).

Conclusions: The Baerveldt-350 group had a higher success rate than the Ahmed-FP7 group after 1 year of follow-up, but required a greater number of interventions.

Financial disclosure(s): Proprietary or commercial disclosure may be found after the references.