Prospective Randomized Study of 1, 2, or 3 Trabecular Micro-Bypass Stents in Open-Angle Glaucoma Uncontrolled on 1-3 Medications
To assess intraocular pressure (IOP) lowering effects of 1, 2 or 3 iStents as a stand-alone surgical procedure in open angle glaucoma (OAG) subjects who were previously not controlled on 1-3 ocular hypotensive medications.
Prospective, randomized study by the MIGS Study Group. Phakic or pseudophakic subjects with OAG and IOP 18 - 30 mmHg on 1-3 ocular hypotensive medications were enrolled. After preoperative medication washout, 120 eligible subjects with unmedicated IOP 22 - 30 mmHg were randomized in 1:1:1 ratio to implantation of 1, 2 or 3 stents (Glaukos). One year efficacy endpoints were Month 12 IOP reduction ≥ 20% and IOP ≤ 18 mmHg. Safety evaluations through five years included slit-lamp and optic nerve evaluation, BCVA and adverse events. To date, 119 subjects have been followed 18 months.
Mean preoperative post-washout IOP was 25.0 mmHg in 1-stent and 2- stent eyes and 24.9 mmHg in 3-stent eyes. All eyes reported with M12 IOP reduction ≥ 20% and ≤ 18 mmHg. Furthermore, 57%, 84% and 92% of 1, 2 and 3-stent eyes, respectively, had IOP reduction ≥ 40%; and 74%, 95% and 100% of 1, 2 and 3-stent eyes, respectively had IOP ≤ 15 mmHg. Mean unmedicated M18 IOP was 15.6 mmHg, 13.9 mmHg and 12.3 mmHg in the three respective groups. Over 18 months, 5 eyes (1 in 1-stent group and 2 in each of the 2-stent and 3-stent groups) reported with BCVA loss ³ 2 lines.
Eighteen-month results following stent implantation in OAG showed significant IOP reduction after implantation with a single stent, further IOP reduction to < 14 mmHg with multiple stents, reduction in drug burden in all patients, and an overall favorable safety profile with both single and multiple stent implantation.