New XEN63 Gel Stent Implantation in Open-Angle Glaucoma: A Two-Year Follow-Up Pilot Study

Purpose: The XEN gel stent was developed to reduce the risks of filtration surgery by standardizing the outflow of aqueous humor into the subconjunctival space. Recently, a modified version of the XEN63 gel stent was introduced. The goal of this study was to assess its efficacy and safety.Methods: This is a prospective, nonrandomized, observational, consecutive case series study at a single tertiary centre. Patients with open-angle glaucoma with above target intraocular pressure (IOP) despite maximal tolerated medication were included. The primary outcome was a change of median IOP. Secondary outcomes included a change in the number of medications, complete success, needling and complication rates. Success was defined as a lowering of IOP > 20% from baseline and IOP & LE; 14 mmHg. Complete success indicated that the target IOP was reached without medications.Results: Six patients were included. The median IOP decreased from 35.5 mmHg (25.0-40.0 mmHg) at baseline to 11.5 mmHg (4.0- 15.0 mmHg, p = 0.03), and median IOP-lowering medication was reduced from 4.0 (3.0-4.0) at baseline to 0 (0-1.0, p = 0.03) after two years. Five patients (83.0%) had a complete success after two years. Two patients (33.0%) required a needling procedure. Three patients (50.0%) required an intervention due to symptomatic hypotony within the first three weeks postoperatively. Hypotony resolved completely or was asymptomatic after three months.Conclusion: Our study demonstrated a statistically significant reduction in both IOP and number of IOP-lowering medications. Complications were well manageable and had no long-term sequelae.