Coexistent primary open-angle glaucoma and cataract: interim analysis of a trabecular micro-bypass stent and concurrent cataract surgery.

PURPOSE: To evaluate the safety and efficacy of the iStent Trabecular Micro-bypass Stent in patients undergoing concurrent cataract and glaucoma surgery. METHODS: Prospective, 24-month, uncontrolled, multicenter, multicountry evaluation of 58 patients with uncontrolled primary open-angle glaucoma (including pseudoexfoliation and pigmentary) and cataract. Patients underwent clear cornea phacoemulsification followed by ab interno gonioscopically guided implantation of the iStent. Of the 48 per protocol population, 42 patients completed 12 months of the 24-month study, and their data are included in this interim analysis. RESULTS: At baseline, mean (+/-SD) intraocular pressure (IOP) was 21.7+/-3.98 mmHg. At 12 months, mean IOP was reduced to 17.4+/-2.99 mmHg, a mean IOP reduction of 4.4+/-4.54 mmHg (p<0.001, 18.3%). At baseline, patients were taking a mean 1.6+/-0.8 medications. By 12 months, the mean number of medications was reduced to 0.4+/-0.62 (p<0.001). Half the patients achieved an IOP < or =18 mmHg and were able to discontinue hypotensive medication by the 12-month visit. The most commonly reported device-related adverse events were the appearance of stent lumen obstruction (7 eyes) and stent malposition (6 eyes). None of the adverse events were deemed serious. CONCLUSIONS: In patients undergoing concurrent cataract and glaucoma surgery, the iStent was safe and efficacious for the reduction of IOP and medication therapy.

Initial clinical experience with the trabecular micro-bypass stent in patients with glaucoma.

This study was undertaken to evaluate the efficiency of a trabecular micro-bypass stent designed to allow direct aqueous drainage from the anterior chamber into Schlemm's canal in patients with glaucoma. In this prospective case series of 6 patients with open-angle glaucoma, the microstent was inserted ab interno under local anesthesia in an ophthalmic operating room. Patients were seen postoperatively at 1 to 2 d, 1 wk, and 1, 2, 6, and 12 mo. All stents were successfully placed within Schlemm's canal. Mean intraocular pressure (IOP) at preoperative baseline was 20.2+/-6.3 mm Hg (range, 14-31 mm Hg). Mean IOP decreased during the immediate postoperative period to approximately 12 to 13 mm Hg and was stabilized at 14 to 15 mm Hg with reduction of medication throughout 1 y of follow-up. No major complications occurred. According to observations reported in this feasibility study, the microstent was effective in reducing IOP and in decreasing the number of glaucoma medications required to control IOP. Implantation procedures were safe, and stents remained in place throughout the follow-up period. None of the complications traditionally associated with filtering surgery were reported. Further research on this stent in a larger group of patients is needed to assess its role in glaucoma therapy.