Efficacy and safety of XEN®-Implantation vs. trabeculectomy: Data of a "real-world" setting

Objective To compare surgical success, postoperative intraocular pressure and complication rates between trabeculectomy and XEN gelstent surgery in a cohort of glaucoma patients in a typical clinical setting. Methods A retrospective cohort study of consecutive patients with refractory open-angle glaucoma including patients who underwent either stand-alone XEN gelstent insertion with Mitomycin C or trabeculectomy with Mitomycin C between 2016 and 2018 at the University Eye Hospital Mainz, Germany. Primary outcome measure was the proportion of surgical success 1 year after surgery. Patients with an IOP <= 18mmHg, an intraocular pressure reduction of >20% and in no need of revision surgery or topical medication were considered a complete surgical success. If topical therapy was necessary, they were considered a qualified success. Multivariable logistic regression analysis was carried out for the primary outcome including gender, age, preoperative intraocular pressure and number of medication classes used preoperatively as adjustment variables. Results 171 eyes of 144 patients were included, including 82 eyes of 58 patients in the XEN group and 89 eyes of 86 patients in the trabeculectomy group. The primary outcome defined as the proportion of surgical success after 1 year (mean 11.1 months +/- 2.2) was similar for both groups. The complete success proportion was 65.5% (95%-CI: 55.6-75.9%) in the trabeculectomy group, and 58.5% (95%-CI: 47.6-69.4%) in the XEN group and not statistically different in our analysis model (crude OR = 0.61; 95%-CI: 0.31-1.22; adjusted OR = 0.66; 95%-CI: 0.32-1.37). The intraocular pressure reduction, as secondary outcome measure, was higher in the trabeculectomy group (10.5 mmHg) compared to the XEN group (7.2 mmHg; p = 0.003) at the 12-month follow-up. Conclusion Both XEN gelstent implantation and trabeculectomy show similar proportions of surgical success and of complications and are therefore both recommendable for clinical routine. However, trabeculectomy seems to be more effective in lowering intraocular pressure than the XEN implantation. A prospective randomized clinical trial is necessary to evaluate differences in the long-term clinical outcome.