Long-term Outcome of Ahmed Glaucoma Valve Implantation in Eyes With Intractably Raised Intraocular Pressure Following Pars Plana Vitrectomy

Ahmed glaucoma valve (AGV) implantation led to a significant reduction in intraocular pressure (IOP) and in antiglaucoma medications in vitrectomized eyes in previously nonglaucomatous eyes. The most common indication for vitrectomy was ocular trauma-related complications.The purpose of this study was to report the long-term outcomes of AGV implantation in patients of uncontrolled IOP after pars plana vitrectomy (PPV).Medical records of patients (age 18 y and above) who underwent AGV implantation between January 2006 and December 2017 for uncontrolled IOP following PPV with ≥2 years follow-up were reviewed. The underlying etiology for PPV, IOP, best-corrected visual acuity, and number of antiglaucoma medications (AGMs) were recorded at baseline. The main outcomes measures were IOP, number of AGM, best-corrected visual acuity, and postoperative complications. Postoperative complications were classified as early (≤3 mo)/intermediate (>3 mo to ≤1 y), or late (>1 y).In all, 78 eyes of 78 patients with a mean age of 38.06±17.83 years were included. The mean follow-up was 70.46±36.96 (range: 24 to 180) months. The main underlying etiology for PPV was trauma (38.4%) followed by rhegmatogenous retinal detachment (28.2%). The mean preoperative IOP was 29.33±9.84 mm Hg with an average of 4.07±1.2 AGM. The mean IOP and number of AGM was significantly reduced in all follow-up visits (P<0.0001) following AGV implantation. The cumulative probability of success was 92.3%, 80.7%, and 74% at 2, 5, and 10 years, respectively. Thirty-one complications were observed in 25 (32%) eyes and reoperation (23 procedures) was performed in 22 (28.2%) eyes.AGV implantation had good outcome in patients with intractably elevated IOP following PPV. Trauma-related pathologies were a major contributor to the indications for PPV and had more chances of failure following AGV implantation.