Comparison of the Ahmed and Baerveldt glaucoma shunts with combined cataract extraction.

Objective: To compare the surgical outcomes of combined phacoemulsification with either Ahmed glaucoma valve (AGV) or Baerveldt glaucoma implant (BGI).
Design: Retrospective cohort study.
Participants: A total of 104 eyes that underwent combined phacoemulsification with either AGV (PhacoAGV; n = 57) or BGI (PhacoBGI; n = 47) implantation.
Methods: Failure was defined as uncontrolled intraocular pressure (IOP; <5 mm Hg, ≥18 mm Hg, or <20% reduction), additional glaucoma surgery, vision-threatening complications, or progression to no-light-perception vision.
Results: The PhacoAGV group was older (p = 0.03), had poorer baseline visual acuity (VA; p = 0.001), and had fewer previous glaucoma surgeries (p = 0.04). Both groups had similar baseline IOP (PhacoAGV: 26.4 ± 8.3 mm Hg; PhacoBGI: 25.7 ± 7.3; p = 0.66) and glaucoma medications (PhacoAGV: 3.8 ± 1.0; PhacoBGI: 3.6 ± 1.5; p = 0.54). At 2 years, failure rates were 44% in the PhacoAGV group and 23% in the PhacoBGI group (p = 0.02). Both groups had similar mean IOP reduction (PhacoAGV: 45%; PhacoBGI: 47%, p = 0.67) and medication use reduction (PhacoAGV: 47%; PhacoBGI: 58%, p = 0.38). The PhacoBGI group had higher IOP and medication use up to 1 month (p < 0.05). Both groups improved in VA from baseline (p < 0.05) and had similar overall complication rates (p = 0.31). The PhacoBGI group required more overall interventions (p < 0.0005).
Conclusions: This comparative study found no difference in IOP, glaucoma medications, or complication rates between PhacoAGV and PhacoBGI at 2 years, despite BGIs being implanted in patients at higher risk for failure. The PhacoAGV group had higher failure rates at 2 years. Both groups had significant improvements in VA due to removal of their cataracts. The PhacoBGI group required more interventions, but most of these were minor slit-lamp procedures.
(Copyright © 2018. Published by Elsevier Inc.)