• The Ahmed Versus Baerveldt Study: 5-Year Outcomes

    Written By: Marianne Doran and edited by Susan M. MacDonald, MD

    Journal Highlights

    Ophthalmology, October 2016

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    In an international multicenter ran­domized trial, Christakis et al. com­pared 2 frequently used aqueous shunts in adult patients whose glaucoma was not controlled by medical therapy or who were at high risk of trabeculecto­my failure. They found that both the Ahmed and Baerveldt devices reduced intraocular pressure (IOP) and need for medication.

    A total of 238 patients were ran­domized to receive either an Ahmed-FP7 valve implant (n = 124) or a Baerveldt-350 implant (n = 114). The primary outcome measure was failure, defined as IOP outside the target range (5-18 mm Hg) or reduction of <20% from baseline at 2 consecutive visits after 3 months; severe vision loss; or de novo glaucoma surgery. Secondary outcome measures included IOP, medi­cation use, visual acuity, complications, and interventions.

    Baseline characteristics were similar between the 2 device groups. Mean preoperative IOP was 31.4 ± 10.8 mm Hg 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 = .04).

    In both groups, the main reason for failure was high IOP. The cumulative de novo glaucoma reoperation rate was 18% in the Ahmed group and 11% in the Baerveldt group (p = .22). Hypotony resulted in failure in 5 patients (4%) in the Baerveldt group compared with none in the Ahmed group (p = .02). Mean IOP was 16.6 ± 5.9 mm Hg in the Ahmed group (47% reduc­tion) and 13.6 ± 5.0 mm Hg in the Baerveldt group (57% reduction, p = .001).

    Mean medication use was 1.8 ± 1.5 medications in the Ahmed group (44% reduction) and 1.2 ± 1.3 in the Baerveldt group (61% reduction; p = .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.

    The authors concluded that 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, but there was also a small risk of hypotony, which was not seen in the Ahmed group.

    The original article can be found here.