Standalone Implantation of 2–3 Trabecular Micro-Bypass Stents (iStent inject ± iStent) as an Alternative to Trabeculectomy for Moderate-to-Severe Glaucoma

Introduction This retrospective consecutive study compared standalone implantation of multiple (2–3) trabecular micro-bypass stents (iStent inject ± iStent) (Multi-Stent group) vs trabeculectomy + mitomycin C (Trab group) in moderate to severe open-angle glaucoma (OAG). Methods Eligible patients underwent Multi-Stent or Trab surgery from 2018 to 2020 and had at least 3-month follow-up; visual field mean deviation (VF MD) − 6 dB or worse; inadequate prior response to maximum medications ± laser procedures; and had trabeculectomy as their next planned intervention. Primary effectiveness, safety-adjusted treatment success, was defined as ≥ 20% intraocular pressure (IOP) reduction on the same or fewer medications, without clinically significant safety events (severe complications, secondary surgeries, reinterventions). Secondary effectiveness included mean IOP and medications; qualified and complete attainment of target IOP (≤ 21/18/15/12 mmHg and > 6 mmHg); health-economic and quality-of-life (QoL) measures; and 2-vs-3-stent subgroup analysis. Results The baseline groups ( n = 70 Multi-Stent/40 Trab) were similar: mean IOP (21.1 mmHg/22.3 mmHg); medications (2.87/3.10 medications); disease stage (30%/35% severe); VF MD (− 10.1 dB/− 10.4 dB); and mean last follow-up (LFU, 13.1 months/15.7 months) (all differences non-significant). Primary effectiveness: treatment success at LFU was 62.9% vs 30.0% in Multi-Stent vs Trab eyes, respectively ( p = 0.001). Secondary effectiveness: At LFU in Multi-Stent vs Trab groups, respectively: mean IOP decreased by 31% to 14.2 mmHg ( p