Comparing Outcomes of 45 m Gelatin Stent Placed ab Externo with Open Conjunctiva to ab Externo with Closed Conjunctiva

Purpose: Compare outcomes of a gelatin stent (XEN45 Gel Stent [XGS]) placed either ab externo with open conjunctiva (AEO) or ab externo with closed conjunctiva (AEC) with or without cataract surgery in patients with glaucoma. Design: Retrospective nonrandomized comparative study. Participants: A total of 86 eyes from 86 glaucoma patients who received XGS placed either AEO (N = 49) or AEC (N = 37) with or without cataract surgery between May 2019 and April 2022 at Massachusetts Eye and Ear. Methods: Reviewed and analyzed 809 visits from patient charts from a level 3 triage center. Main Outcome Measures: Intraocular pressure (IOP), medication burden, Kaplan-Meier (KM) success rates, 5-fluorouracil (5 -FU) impact, and complications. Results: Baseline demographics were similar between both groups, except for baseline IOP and glaucoma type. Both AEO and AEC procedures resulted in significant patterns of IOP and medication reduction from baseline up to 1 year. The AEO procedure had significantly higher KM qualified success (QS) rates than the AEC procedure, but similar complete success (CS) rates. Under QS, the cumulative probability of survival was 73% in the AEO group and 51% in the AEC group at month 6 and 62% in the AEO group and 20% in the AEC group at year 1. Under CS, the cumulative probability of survival was 41% in the AEO group and 37% in the AEC group at month 6 and 29% in the AEO group and 14% in the AEC group at year 1. The AEO procedure had significantly more IOP reduction than the AEC procedure at all postoperative time points beyond week 2, but similar medication burden reduction. At postoperative year 1 (POY1), the mean IOP was reduced to 10.72 +/- 5.71 mmHg on 1.16 +/- 1.68 medications after AEO and 17.03 +/- 2.37 mmHg on 1.59 +/- 1.21 medications after AEC. Phacoemulsification (phaco) was not a significant factor while 5 -FU usage trended toward significance. Procedure time was longer for standalone XGS AEO. Conclusions: We demonstrate that both placements reduce medication and IOP from baseline, with AEO placement having more favorable XGS success rates and IOP control at the expense of longer procedure time and greater 5 -FU usage. Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article. Ophthalmology Glaucoma 2024;7:66-74 (c) 2023 by the American Academy of Ophthalmology. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).