Comparative Outcomes of Standalone Xen63 Gel Stent and Preserflo Microshunt Implantation: A Multicenter Study.

Purpose: To evaluate the intraocular pressure (IOP)-lowering efficacy and adverse event profile of Xen63 gel stent compared to the Preserflo microshunt. Methods: Retrospective, multicenter, two-arm cohort study comparing 65 eyes undergoing standalone Xen63 implantation and 75 eyes undergoing standalone Preserflo implantation, all with intraoperative mitomycin C (MMC). Primary outcome was complete success, defined as all of the followings: 1) no two consecutive IOP readings >17mmHg, 2) ≥20% IOP reduction from baseline; 3) no clinical hypotony (IOP <6 mmHg associated with loss of ≥2 lines of vision); and 4) no use of glaucoma medications. Secondary outcomes included success at different IOP cut offs, qualified success (allowing medications), change in IOP, medications, complications, interventions, and re-operations. Results: At 12 months, complete success was achieved in 61.5% of eyes in the Xen63 group and 73.9% in the Preserflo group (p = 0.13). Postoperative complications were more frequent in the Xen63 group compared with the Preserflo group (61.5% vs. 29.3%, p = 0.0002). Postoperative interventions were required at similar rates between groups (Xen63 30.8% vs. Preserflo 28.0%, p = 0.85); however, reoperations were performed more frequently in the Xen63 group (16.9% vs. 4.0%, p = 0.01). Non-Caucasian ethnicity was associated with an increased risk of surgical failure (HR 2.57; 95% CI, 1.26-5.23). Conclusion: Both devices achieved comparable success rates, median IOP reduction, and postoperative medication burden; however, the Xen63 group experienced a higher rate of complications and reoperations.