Surgical Outcomes of XEN45 Gel Stent Using Ab Interno Technique in Open-Angle Glaucoma: A 2-Year Follow-Up Study

Background/Objectives: This study aims to evaluate the long-term efficacy and safety of ab interno techniques using minimally invasive glaucoma surgery (MIGS), specifically XEN gel stent implantation, by evaluating its 2-year outcomes in patients with primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (PXG). Methods: This retrospective single-center study consecutively included 31 eyes of 31 patients with POAG or PXG who underwent XEN gel stent implantation. Patients were followed for 24 months, with assessments at multiple time points. Success was defined as achieving an IOP of less than 14 mmHg and a reduction of more than 20% from preoperative IOP without additional glaucoma surgery. Bleb morphology was evaluated using anterior segment optical coherence tomography (AS-OCT) and slit-lamp photographs. Postoperative interventions and complications were also recorded. Results: At 24 months, complete success and qualified success rates were 35.5% (11/31) and 51.6% (16/31), respectively. There was no difference in surgical success rates at 2 years based on the tip location (intraconjunctiva, intratenon, and uviform) on the 1st postoperative day. Patients with high sparse wall on AS-OCT imaging or avascular bleb morphology via slit-lamp photography at 6 months postoperatively had higher complete success rates at 2 years than those without (p = 0.007, p = 0.009, respectively). Patients with avascular bleb types at 6 months postoperatively had higher qualified success rates at 2 years compared with the vascular types (p = 0.038). Needling was performed in 32.3% of eyes, with secondary surgical procedures required in 16.1% of eyes. The most common adverse event was hypotony, occurring in 67.7% of eyes on the 1st postoperative day but resolving within 6 months. Conclusions: The ab interno XEN gel stent is an effective and minimally invasive option for managing POAG and PXG, with long-term success predicted by the AS-OCT assessment of bleb morphology at 6 months. Proactive postoperative management, emphasizing early intervention and monitoring, is crucial for maintaining optimal outcomes.