Elsevier

Ophthalmology

Volume 123, Issue 10, October 2016, Pages 2093-2102
Ophthalmology

Original article
The Ahmed Versus Baerveldt Study: Five-Year Treatment Outcomes

Presented at: American Academy of Ophthalmology, October 22–25, 2011, Orlando, Florida; November 10–13, 2012, Chicago, Illinois; November 13–17, 2015, Las Vegas, Nevada; American Glaucoma Society, March 1–4, 2012, New York, New York; Canadian Ophthalmological Society, June 26–29, 2010, Quebec City, Canada; June 9–12, 2011, Vancouver, Canada; June 26–30, 2012, Toronto, Canada.
https://doi.org/10.1016/j.ophtha.2016.06.035Get rights and content

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.

Section snippets

Methods

The AVB study methodology is described in detail in our baseline article17 and will be summarized in the current article. Institutional review board approval was obtained at each clinical center, and the study protocol is registered on www.ClinicalTrials.gov (NCT00940823).

Baseline Characteristics

A total of 238 patients were recruited and randomized: 124 (52%) to the Ahmed group and 114 (48%) to the Baerveldt group. The baseline characteristics of the study group were similar and are presented in Table 1. Mean patient age was 66 years old with uncontrolled disease as evidenced by a mean preoperative IOP of 31 mmHg on 3 classes of glaucoma medications. Many patients had failed trabeculectomy with antimetabolite (37%) or had high-risk disease, including neovascular (21%) or uveitic (10%)

Discussion

The AVB study is an international, multicenter, randomized trial comparing the 2 most frequently used aqueous shunts. Enrolled patients had uncontrolled glaucoma despite maximum tolerated medical therapy, with 37% of patients having failed trabeculectomy with mitomycin C and 31% of patients having neovascular or uveitic glaucoma. Aqueous shunts are being increasingly used in this patient population.12 An IOP target of ≤18 mmHg was selected on the basis of Advanced Glaucoma Intervention Study

References (33)

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Supplemental material is available at www.aaojournal.org.

Financial Disclosure(s): The author(s) have made the following disclosure(s): P.J.H.: Personal fees – Abbott Medical Optics.

I.I.K.A.: Personal fees – Abbott Medical Optics and New World Medical.

The AVB study is supported by a research grant from the Glaucoma Research Society of Canada, Toronto, Canada (I.I.K.A., P.G.C.) and a departmental challenge grant from the Research to Prevent Blindness, Inc, New York, New York (J.C.T.). Our research funding sponsors had no role in the design or conduct of the study.

Author Contributions:

Conception and design: Christakis, Kalenak, Tsai, Zurakowski, Kammer, Harasymowycz, Mura, Cantor, Ahmed

Data collection: Christakis, Kalenak, Tsai, Zurakowski, Kammer, Harasymowycz, Mura, Cantor, Ahmed

Analysis and interpretation: Christakis, Kalenak, Tsai, Zurakowski, Kammer, Harasymowycz, Mura, Cantor, Ahmed

Obtained funding: Not applicable

Overall responsibility: Christakis, Kalenak, Tsai, Zurakowski, Kammer, Harasymowycz, Mura, Cantor, Ahmed

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