Ahmed versus baerveldt glaucoma drainage implantation in patients with markedly elevated intraocular pressure (≥30mm Hg)

Purpose: Glaucoma patients with markedly elevated intraocular pressure (IOP) are at risk for developing severe hypotony-related complications. The goal of this study was to compare the surgical outcomes of the Ahmed Glaucoma Valve (AGV) and the Baerveldt Glaucoma Implant (BGI) in this patient population. Methods: Patients with preoperative IOPZ30mm Hg were included. Outcome measures were: (1) surgical failure (IOP>21 mm Hg or <30% reduction from baseline or IOPr5mm Hg on 2 consecutive follow-up visits after 3 mo, or additional glaucoma surgery, or loss of light perception) and (2) surgical complications. Results: A total of 75 patients were included: 37 in the AGV group and 38 in the BGI group. The mean±SD follow-up was 2.3±1.6 years for the AGV group and 2.4±1.7 years for the BGI group (P=0.643). Mean preoperative IOP was 38.7±6.5mm Hg for the AGV group and 40.8±7.6mm Hg for the BGI group. At the last follow-up, 10 (27.0%) patients failed in the AGV group compared with 6 (15.8%) patients in the BGI group (P=0.379). The BGI group had higher rate of flat or shallow anterior chamber (n=4, 10%) compared with the AGV group (n=0, 0%) (P=0.043). Conclusions: Failure rates of AGV and BGI in patients with IOPZ30mm Hg were comparable. There were more early hypotony-related complications in the BGI group; however, none were vision threatening. Both glaucoma drainage implants were effective in treating patients with uncontrolled glaucoma in an emergency setting.