Objective: Compare surgical success, risk factors and post-operative course of the SIBS microshunt, gelatin 45μm microstent, and trabeculectomy with mitomycin C (MMC) as a primary surgical intervention in patients with glaucoma. We present a multicenter,12-month, retrospective, non-randomized, interventional case series.

Methods: Multicenter,12-month, retrospective, non-randomized, interventional case series. Methods: Consecutive patients with glaucoma on maximally tolerated medical therapy received either primary SIBS microshunt, gelatin 45um microstent, or trabeculectomy with MMC as a stand-alone procedure at one of six participating centers (Canada, Italy, Netherlands, Belgium, Singapore, Dominican Republic) from August 2015 to August 2020. Main outcome measures were proportion of eyes at 12-months with (1) no two consecutive IOPs > 17 mmHg or clinical hypotony (IOP < 6 mmHg with a loss of> 2 lines of vision), without (complete) or with (qualified) glaucoma medications; and (2) ≥20%reduction from baseline IOP. Secondary outcomes included IOP thresholds of 14 mmHg and 21 mmHg, median IOP, medications, risk factors, post-operative interventions, complications, and reoperations.

Results: Records from 577 eyes from 521 patients with SIBS microshunt (n=235), gelatin 45μm microstent (n=201) or trabeculectomy (n=141) were included. Baseline decision IOP was lower in the SIBS group and baseline number of glaucoma medications was also lower in the SIBS and trabeculectomy groups. After 12-months follow up, complete success occurred in 68.8% of patients with SIBS microshunt, 46.2% with gelatin 45μm microstent and 58.0% with trabeculectomy (p=0.0002). Qualified success occurred in 89.7%, 70.1% and 83.6% of eyes, respectively (p=0.0002). In the multivariate analysis, eyes receiving a gelatin 45μm microstent relative to SIBS microshunt (HR 2.0; 95%CI 1.5 - 2.7), trabeculectomy relative to SIBS microshunt (HR 1.6; 95%CI 1.2 - 2.2), or intra-operative MMC dose less than 0.4mg/ml (HR 1.5; 95%CI 1.1 - 2.0) was significantly associated with failure. Complications occurred in 33.6%, 42.8% and 56% of eyes (p= 0.0001); needling in 12.3%, 29.9% and 22% (p<0.0001); revisions in 10.6%, 8.5% and 8.5% (p=0.68); and reoperations in 5.5%, 13.9% and 7.8% (p<0.001) with SIBS microshunt, gelatin 45μm microstent, or trabeculectomy, respectively.

Conclusions: Overall, patients with the SIBS microshunt achieved higher success rates compared to both trabeculectomy and the gelatin 45μm microstent group, with fewer postoperative complications, interventions, and reoperations for glaucoma.