Short-Term Outcomes of Xen-45 Gel Stent Ab Interno Versus Ab Externo Transconjunctival Approaches

Abstract

Précis: Ab externo transconjunctival placement of the Xen-45 gel stent offers a faster surgical approach and more rapid visual recovery with similar pressure-lowering and complication rates when compared with implantation by the ab interno approach. Purpose: Compare outcomes of closed conjunctival Xen-45 implantation techniques: ab interno versus ab externo transconjunctival. Material and Methods: Single-center, retrospective study of 70 patients undergoing Xen-45 implantation between 2017 and 2020. Group 1 (n=29) had ab interno placement, Group 2 (n=41) had transconjunctival ab externo placement. Primary outcome measures were intraocular pressure (IOP) and medication use. Secondary measures were bleb revision rates, surgical time, time to return to baseline visual acuity, and complication rates. Results: Group 1, preoperative IOP was 22.8±7.5 mmHg on 3.8±0.9 IOP-lowering medications and the postoperative IOP at last follow-up was 11.6±2.8 mmHg on 1.6±1.3 medications. Group 2, preoperative IOP was 25.6 mmHg±7.8 mmHg on 3.7±1.1 medications and the postoperative IOP at last follow-up was 12.4±3.6 mmHg on 1.5±1.3 medications. There was no difference in postoperative IOP or medications between the 2 groups (P<0.05). The average surgical time for Group 2 was 25±6.5 minutes to 37±7.3 minutes for Group 1 (P<0.001). Group 2 showed 88% of patients returning to baseline visual acuity at week 2 compared with 66% in Group 1 (P<0.05). Bleb revision rates, failure rates, and complication rates were comparable between both groups (P>0.05). Conclusion: IOP, medication use, complications, bleb revision rates, and failure rates were similar between ab interno and ab externo transconjunctival approaches. The ab externo group had faster surgical times and postoperative visual recovery despite higher number of patients with previous glaucoma procedures