The Ahmed Versus Baerveldt Study: Five-Year Treatment Outcomes

Panos G. Christakis, Jeffrey W. Kalenak, James C. Tsai, David Zurakowski, Jeffrey A. Kammer, Paul J. Harasymowycz, Juan J. Mura, Louis B. Cantor, Iqbal I.K. Ahmed

Research output: Contribution to journalArticlepeer-review

145 Scopus citations


Purpose To compare 2 frequently used aqueous shunts for the treatment of glaucoma. Design International, multicenter, randomized trial. Participants Patients aged 18 years or older with uncontrolled glaucoma despite maximum tolerated medical therapy, many of whom had failed or were at high risk of failing trabeculectomy. Methods Eligible patients were randomized to receive an Ahmed-FP7 valve implant (New World Medical, Inc, Rancho Cucamonga, CA) or a Baerveldt-350 implant (Abbott Medical Optics, Inc, Santa Ana, CA) using a standardized surgical technique. Main Outcome Measures The primary outcome was failure, defined as intraocular pressure (IOP) outside the target range (5–18 mmHg) or reduced <20% from baseline for 2 consecutive visits after 3 months, severe vision loss, or de novo glaucoma surgery. Secondary outcomes measures included IOP, medication use, visual acuity, complications, and interventions. Results A total of 238 patients were randomized; 124 received the Ahmed-FP7 implant, and 114 received the Baerveldt-350 implant. Baseline characteristics were similar between groups. Mean preoperative IOP was 31.4±10.8 mmHg on 3.1±1.0 glaucoma medications. At 5 years, the cumulative failure rate was 53% in the Ahmed group and 40% in the Baerveldt group (P = 0.04). The main reason for failure in both groups was high IOP, and the cumulative de novo glaucoma reoperation rate was 18% in the Ahmed group and 11% in the Baerveldt group (P = 0.22). Hypotony resulted in failure in 5 patients (4%) in the Baerveldt group compared with none in the Ahmed group (P = 0.02). Mean IOP was 16.6±5.9 mmHg in the Ahmed group (47% reduction) and 13.6±5.0 mmHg in the Baerveldt group (57% reduction, P = 0.001). Mean medication use was 1.8±1.5 mmHg in the Ahmed group (44% reduction) and 1.2±1.3 mmHg in the Baerveldt group (61% reduction, P = 0.03). The 2 groups had similar complication rates (Ahmed 63%, Baerveldt 69%) and intervention rates (Ahmed 41%, Baerveldt 41%). Most complications were transient, and most interventions were slit-lamp procedures. Conclusions Both implants were effective in reducing IOP and the need for glaucoma medications. The Baerveldt group had a lower failure rate and a lower IOP on fewer medications than the Ahmed group, but had a small risk of hypotony that was not seen in the Ahmed group.

Original languageEnglish
Pages (from-to)2093-2102
Number of pages10
Issue number10
StatePublished - 1 Oct 2016
Externally publishedYes


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