iStent inject Trabecular Micro-Bypass with or Without Cataract Surgery Yields Sustained 5-Year Glaucoma Control

Abstract

Introduction: This study evaluated the 5-year effectiveness and safety of iStent inject Ò trabecular micro-bypass with or without cataract surgery (Combined or Standalone, respectively) in patients with open-angle glaucoma (OAG). Methods: This prospective longitudinal case series included consecutive iStent inject cases from a single surgeon at a large German academic hospital. Intraocular pressure (IOP), medications, safety, and indicators of disease stability through 5 years were assessed in the Overall cohort and in subgroup analyses stratified by usage (Combined or Standalone). Results: Preoperative mean IOP in the Overall cohort (n = 125) was 23.5 ± 6.2 mmHg on 2.68 ± 1.02 mean medications, reducing to 14.1 ± 1.8 mmHg on 0.77 ± 0.82 medications at 5 years (40% and 71% reductions, respectively; both p\0.001). All but 1 eye ([99%) were on medication(s) preoperatively, but 46% were medication-free at 5 years (p\0.001). In Combined eyes (n = 81), mean IOP decreased by 39% (22.6 mmHg to 13.8 mmHg, p\0.001) and medications by 69% (2.52 to 0.78, p\0.001). In Standalone eyes, mean IOP reduced by 42% (25.3 mmHg to 14.6 mmHg, p\0.001) and medications by 75% (2.98 to 0.74, p\0.001). At final follow-up, 83% of eyes had achieved C 20% IOP reduction, and all but 1 eye ([99%) had the same or lower IOP versus preoperative; all eyes (100%) maintained or reduced their medication burden versus preoperative. Favorable safety included 0 intraoperative complications and 0 filtration surgeries through 5 years. Long-term indicators of disease stability (visual fields, retinal nerve-fiber layer thickness, and cup:disc ratio) were unchanged over the course of 5-year follow-up. Conclusions: iStent inject produced significant and durable 5-year reductions in IOP (nearly 10-mmHg reduction) and medications (nearly 2-medication reduction), with stable disease parameters over time. Combined and Standalone subgroups had similar outcomes.

Effectiveness and Safety of iStent Infinite Trabecular Micro-Bypass for Uncontrolled Glaucoma

“…17,18 Beyond the pivotal trials evaluating combined procedures for mild to moderate primary OAG, multiple additional studies have shown that implantation of iStent and iStent inject can effectively and safely reduce IOP and medication burden in both combined (with phacoemulsification) and stand-alone (without phacoemulsification) surgery. [20][21][22][23][24][25][26][27][28][29][30][31][32] The evidence also demonstrates an incremental increase in IOP-reducing and medication-reducing effect with a higher number of iStents (1 vs. 2 vs. 3) 20,[33][34][35][36][37][38][39] and suggests a specific incremental benefit of 3 over 2 stents. 16 Subconjunctival bleb-associated surgeries, which bypass the eye's natural drainage system and create a filtering bleb (eg, trabeculectomy, tube shunt implantation, XEN Gel Stent implantation, Preserflo), may be considered when greater IOP lowering is required.…”

“…Although the follow-up period of 12 months is of relatively short duration, the iStent infinite has the same mechanism of action and treatment approach as the first-generation iStent and second-generation iStent inject devices, which have shown consistent durability in maintaining IOP and medication reductions for up to 8 years postoperative. [16][17][18][20][21][22][23][24][25][26][27][28][29][30][31][32][37][38][39] Hence, long-term studies with iStent infinite would be expected to demonstrate similarly consistent effectiveness and safety over time. No medication washout was done, as this might have placed the enrolled glaucoma patients at undue risk for optic nerve damage.…”

“…In the United States, all 3 devices are indicated for use in mild to moderate OAG in combination with cataract surgery, supported by randomized controlled pivotal trials demonstrating effective IOP lowering and substantial medication reduction;17–19 in the case of iStent and iStent inject, overall safety parameters in these trials were shown to be comparable to cataract surgery alone 17,18. Beyond the pivotal trials evaluating combined procedures for mild to moderate primary OAG, multiple additional studies have shown that implantation of iStent and iStent inject can effectively and safely reduce IOP and medication burden in both combined (with phacoemulsification) and stand-alone (without phacoemulsification) surgery 20–32. The evidence also demonstrates an incremental increase in IOP-reducing and medication-reducing effect with a higher number of iStents (1 vs. 2 vs. 3)20,33–39 and suggests a specific incremental benefit of 3 over 2 stents 16…”

Clinical and Visual Field Outcomes Following Minimally Invasive Glaucoma Surgery Combined with Cataract Surgery

“… 38 Of note, studies with newer versions of the stents employed in this study, namely XEN 45 and iStent inject, demonstrated significant reduction in visual field loss compared to control. 39 , 40 Moreover, Liu et al demonstrated that the superior hemifield was most affected over a three-year follow-up period in glaucoma patients, although this analysis was after GDD implantation. 20 Our study cohort demonstrated no significant global or regional change in VF metrics over the follow-up period, which indicates a preservation of visual function after MIGS.…”

Posture-Induced Intraocular Pressure Changes after iStent Inject W Combined with Phacoemulsification in Open Angle Glaucoma Patients

“…The iStent inject W (Glaukos Corporation, Laguna Hills, CA, USA) is a bypass implant between the anterior chamber and Schlemm’s canal to decrease aqueous outflow resistance among MIGS [ 20 , 21 ]. Several studies have suggested the IOP lowering effect of dual iStent inject device implantation in mild-to-moderate open-angle glaucoma [ 22 , 23 , 24 , 25 ]. However, posture-induced IOP changes after the MIGS procedures, including iStent inject W, have not been evaluated.…”