Predicting bleb revision after XEN gel stent surgery in a real-world open-angle glaucoma cohort

Abstract Purpose To evaluate the incidence, timing, and risk factors for postoperative needling procedure and incisional bleb revision following XEN gel stent implantation in a large single-center cohort with a long-term follow-up. Methods This retrospective observational cohort study included 773 eyes from 596 patients who underwent XEN gel stent implantation between December 2015 and July 2023. Patients had primary or secondary open-angle glaucoma and at least 12 months of follow-up. Primary outcomes were the need for surgical bleb revision (needling procedure or incisional bleb revision). Secondary outcomes included timing and frequency of interventions. Cox regression models were used to identify risk factors. Results A total of 417 eyes (53.9%) underwent at least one needling procedure, and 137 eyes (17.8%) required incisional bleb revision. Most interventions occurred within the first 100 weeks. Mean time to first needling procedure was 33.6 ± 49.1 weeks, and to first incisional revision 60.9 ± 62.5 weeks. The mean interval between needling procedure followed by incisional revision was 31.8 weeks, and 22.2 weeks for the reverse sequence. Cox regression revealed that male sex (HR 1.43; 95% CI, 1.03–1.99; p = 0.035) and phakic lens status (HR 0.59 for pseudophakia; 95% CI, 0.42–0.82; p = 0.002) were independently associated with incisional bleb revision. No examined baseline variables predicted the need for needling procedures. Conclusion Postoperative bleb interventions are common after XEN gel stent implantation, occurring most frequently within the first two years but also extending into long-term follow-up. Male sex and phakic lens status are associated with a higher risk of incisional bleb revision, while needling procedure appears less dependent on baseline characteristics. These findings may help refine patient counselling, risk stratification, and postoperative management strategies.