7-Year Efficacy and Safety of iStent inject Trabecular Micro-Bypass in Combined and Standalone Usage.

Introduction: This study evaluated 7-year effectiveness and safety of second-generation trabecular micro-bypass implantation (iStent inject) either in combination with cataract surgery or as a standalone procedure (Combined or Standalone subgroups, respectively) in eyes with open-angle glaucoma.

Methods: This prospective, non-randomized, unmasked, longitudinal study included 125 consecutive iStent inject cases of a single surgeon at a large German academic hospital. Patients had considerable preoperative disease burden, with mean intraocular pressure (IOP) of 23.5 mmHg, 84.8% of eyes on ≥ 2 medications, and 38.4% of eyes with prior glaucoma surgery. IOP, medications, adverse events, and secondary surgeries were assessed through 7 years in the Overall cohort and in Combined (n = 81) and Standalone (n = 44) subgroups.

Results: Over 7-year follow-up, mean IOP decreased by 36.2-40.0% in Overall eyes, 34.1-38.9% in Combined eyes, and 39.5-43.5% in Standalone eyes (p < 0.001 at all timepoints for all groups). Meanwhile, mean medications decreased by 59.3-71.3% in Overall eyes, 57.9-69.0% in Combined eyes, and 62.1-76.2% in Standalone eyes (p < 0.001 at all timepoints in all groups). At last follow-up (mean 77.4 months; 92.8% of patients with last visit at 6 or 7 years), 83.7% of Overall eyes, 82.3% of Combined eyes, and 86.4% of Standalone eyes had achieved ≥ 20% IOP reduction vs preoperative. At last follow-up vs preoperative, 100% of eyes in all groups had the same or lower IOP and 100% had the same or lower medication regimen. Safety outcomes were favorable, with no filtration surgeries and only 4.84% of eyes experiencing clinically significant visual field loss over 7 years of follow-up.

Conclusion: iStent inject implantation with or without phacoemulsification produced significant and durable 7-year reductions in IOP (~ 34-44% reduction) and medications (~ 58-76% reduction) while preventing filtering surgery in this cohort of patients with relatively high preoperative disease burden. Combined and Standalone cases had similarly favorable effectiveness and safety.