Evaluation of a Trabecular Micro-Bypass Stent in Pseudophakic Patients With Open-Angle Glaucoma

Purpose of the Study:The purpose of the study was to evaluate the safety and efficacy of the iStent Trabecular Micro-Bypass stent in pseudophakic patients with open-angle glaucoma.Methods:Retrospective, consecutive case series from October 2012 to May 2015 with no exclusion criteria. The series comprised 42 pseudophakic eyes with open-angle glaucoma that were implanted with 1 iStent. Data were collected preoperatively, and postoperative data were collected at 1 day, 1 week, 1, 3 and 6 months, 1 year, 18 months and 2 years. Data included intraocular pressure (IOP), number of glaucoma medications, the incidence of postoperative IOP pressure spikes 15 mm Hg at any timepoint, and the need for additional surgery.Results:The mean preoperative IOP was 20.266.00 mm Hg. At 1 year postoperatively, the mean IOP was 16.34 +/- 3.78 mm Hg (P<0.01). At 2 years postoperatively, the mean IOP was 13.62 +/- 4.55 (P<0.01). The mean number of glaucoma medications was 1.95 +/- 1.01 preoperative and 1.69 +/- 1.28 (P>0.05) at 1 year postoperatively. Postoperatively, 3 eyes (7%) experienced an IOP increase of 15 mm Hg above their baseline IOP that responded to topical therapy. In total, 96% of patients with an IOP19 mm Hg achieved a reduction in IOP at their last collected follow-up.Conclusions:The insertion of the iStent Trabecular Micro-Bypass stent effectively lowers IOP in pseudophakic patients with open-angle glaucoma. Although medication use was not significantly reduced postoperatively at 1 year, 80% of patients either experienced a reduction or no change in medication use. The safety profile appears favorable with a low rate of IOP spikes and only 1 patient requiring additional surgery.