The Pan-American Journal of Ophthalmology (Jan 2020)
Pars plana Ahmed glaucoma valve implantation in refractory glaucoma: Surgical technique and long-term outcomes
Abstract
Purpose: The aim of this study was to evaluate the long-term efficacy of intraocular pressure (IOP) control and complications of pars plana Ahmed glaucoma valve (AGV) implantation in refractory glaucoma patients. Design: This was a prospective interventional study. Materials and Methods: We conducted a single-center study, involving eyes with refractory glaucoma. Study variables were IOP, the number of glaucoma medications, and corrected distance visual acuity (CDVA) evaluated preoperatively and postoperatively at 1 day, 1 week, 1 month, 3 months, 6 months, and every 6 months till the last follow-up. Complete success was defined as absolute if IOP was between 6 and 21 mmHg in the absence of any glaucoma medication and qualified success if IOP was between 6 and 21 mmHg with medication at the last follow-up. Results: The study included 27 patients (29 eyes) with a mean age of 54.28 (standard deviation [SD]: 16.76; range: 11–73) years and a mean follow-up of 21.31 (SD: 20.38; range: 6–60) months. The mean IOP reduced from 38.14 (SD: 7.4; range: 25–50) mmHg preoperatively to 12.76 (SD: 3.92; range: 6–20) mmHg at the last follow-up (P <0.001). CDVA improved in 16 (55.2%) eyes, remained the same in 10 (34.5%) eyes, and worsened in 3 (10.3%) eyes. There was a mean reduction of antiglaucoma medications from 4.07 (SD: 0.26) preoperatively to 0.93 (SD: 1.31) postoperatively (P <0.001). The absolute success rate was 62%, reaching 100% in terms of qualified success. Postoperative complications included vitreous hemorrhage in 4 (13.8%) eyes, transient hypotony in 3 (10.3%) eyes, hyphema in 2 (6.9%) eyes, tube exposure in 2 (6.9%) eyes, and development of a small iris cyst in 1 (3.4%) eye. Conclusion: Pars plana implantation of AGV is a viable option in refractory glaucoma eyes where other surgical options are precluded, as it provides a good success rate with fewer postoperative complications. One must still keep a watch for tube exposure, vitreous incarceration in the tube, vitreous hemorrhage, and future retinal complications.
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