Two-year outcomes of minimally invasive XEN Gel Stent implantation in primary open-angle and pseudoexfoliation glaucoma

Purpose: The aim of this study was to evaluate the efficacy of XEN^® Gel Stent implantation in the treatment of primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (XFG) regarding the reduction of intraocular pressure (IOP) and number of IOP-lowering medications over 2 years.

Methods: In this retrospective, observational, single-centre study, patients with POAG or XFG underwent implantation of the XEN^® Gel Stent with or without combined phacoemulsification. Changes in mean IOP, mean number of IOP-lowering medications, number of postoperative interventions, complete or qualified surgical success rate (defined as IOP < 18 mmHg without or with IOP-lowering medication, respectively) and complete surgical failure rate (defined as the necessity of a glaucoma-related secondary surgical intervention or loss of light perception) were assessed 12 months (12M) and 24 months (24M) postoperatively.

Results: Seventy-nine eyes of 63 patients with open-angle glaucoma were included in the study (71% POAG, 29% XFG). Before surgery, mean IOP was 23.4 ± 7.9 mmHg. IOP was 14.6 ± 3.6 mmHg 12 months postoperatively (-31% from baseline, 95% CI -42% to -20%, n = 30, p < 0.001) and 14.8 ± 4.4 mmHg 24 months postoperatively (-29% from baseline, 95% CI -30% to -41%, n = 28, p < 0.001). Mean number of IOP-lowering medications was significantly reduced from 2.7 ± 1.1 before surgery to 1.0 ± 1.2 (-69%, 95% CI -89% to 46%, p < 0.001) 12 months after surgery and 1.0 ± 1.2 (-64%, 95% CI -91% to -36%, p < 0.001) at 24 months after surgery. Complete surgical success was achieved in 39% (12M) and 34% (24M) of patients and qualified success in 29% (12M) and 27% (24M). 13 (16%) eyes were classified as complete surgical failure. In 62% of the patients needling procedures had to be performed.

Conclusion: The XEN^® Gel Stent is an efficacious minimal invasive glaucoma surgery for primary open-angle and pseudoexfoliation glaucoma, resulting in significant reduction of IOP and a reduction in glaucoma medications from baseline in two-third of treated patients with 2-year follow-up. Frequent follow-up examinations were mandatory to identify early and late bleb failure and additional needling procedures were necessary to reestablish aqueous flow.