Prospective evaluation of microinvasive glaucoma surgery with trabecular microbypass stents and prostaglandin in open-angle glaucoma

PURPOSE: To evaluate the intraocular pressure (IOP) lowering effect of 2 trabecular microbypass stents and postoperative travoprost in patients with open-angle glaucoma (OAG) not controlled on 2 medications preoperatively. SETTING: S.V. Malayan Ophthalmology Centre, Yerevan, Armenia. DESIGN: Prospective open-label nonrandomized study. METHODS: This prospective pilot study involved 39 qualified phakic patients with OAG, medicated IOP between 18 mm Hg and 30 mm Hg, and unmedicated baseline (after washout) IOP between 22 mm Hg and 38 mm Hg. Patients received 2 stents (iStent) through a clear corneal incision and were prescribed travoprost starting the night of postoperative day 1. Intraocular pressure, complications, and various safety measures were assessed at examinations through 18 months and planned for every 6 months thereafter until month 60. A washout of medications was performed 13 months postoperatively. RESULTS: All patients achieved an IOP reduction of 20% or more from baseline to 12 months with reduction of 1 medication and with IOP 18 mm Hg or less. Follow-up through 18 months showed that medicated IOP decreased from 22.2 mm Hg +/- 2.0 (SD) on 2 medications preoperatively to 14 mm Hg or less on 1 medication at the postoperative visits. The mean unmedicated IOP decreased from 25.3 +/- 1.8 mm Hg preoperatively to 17.1 +/- 2.2 mm Hg 13 months postoperatively. No intraoperative or serious device-related adverse events occurred. CONCLUSIONS: Patients with OAG treated with 2 trabecular microbypass stents and 1 presumptive postoperative medication achieved a significant and sustained reduction in IOP and medication through 18 months.