Short-Term Preliminary Results of Outcomes with and without Tenonectomy During Open Conjunctival XEN45 Gel Stent Implantation.

Purpose: To compare outcomes of eyes with and without tenonectomy during ab externo open conjunctival (AEO) implantation of a gelatin stent (XEN45 Gel Stent [XGS]) with mitomycin C. Methods: We conducted a retrospective comparative cohort study of adults aged ≥40 with open-angle glaucoma and preoperative intraocular pressure (IOP) >17mmHg who underwent XGS AEO with or without tenonectomy at a single academic center (April 2021-September 2023). We matched eyes undergoing tenonectomy 1:3 to controls using nearest-neighbor algorithm. The primary outcome was success at 1 year (6 ≤ IOP ≤ 21mmHg, with ≥ 20% reduction from baseline, with or without IOP-lowering medication). Secondary outcomes included IOP, medication burden, visual acuity, and postoperative complications and interventions. Results: We included 40 eyes (38 patients): 10 with tenonectomy and 30 without. At 1 year, 70%, 60%, and 40% of tenonectomy eyes and 55%, 52%, and 36% of non-tenonectomy eyes achieved success at IOP thresholds of 21, 18, and 15 mmHg, respectively (all p>0.05). There were no significant differences between groups in IOP, medication burden, or visual acuity. At 1 year, mean IOP was 14.83 ± 2.08 on 1.13 ± 0.38 IOP-lowering medications in the tenonectomy group and 16.88 ± 1.53 on 1.36 ± 0.31 medications in the non-tenonectomy group. Tenonectomy eyes tended toward more early complications (30% vs 23%, p=0.69), but fewer postoperative interventions (30% vs 57%, p=0.28) and reoperations (20% vs 30%, p=0.70). Conclusion: Both techniques provided effective IOP control and reduced medication burden. In this short-term preliminary study, tenonectomy may be more effective than the traditional technique. Given the small sample size and retrospective design, findings should be interpreted cautiously. More data are needed to guide optimal surgical technique.