Surgical Outcome Comparison of Open Conjunctival Ab Externo Xen 45 Gel Stent Implantation vs Trabeculectomy in Open-angle Glaucoma

Sep 30, 2026

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Evaluate the safety, efficacy, and failure risk factors of open conjunctival ab externo Xen 45 gel stent placement versus trabeculectomy in adults with open-angle glaucoma. In a retrospective single-center cohort of patients over 18 years with baseline IOP >17 mm Hg, eyes without aphakia or missing preoperative data were assigned to either procedure. Success after 1 year required IOP control within predefined limits with adequate reduction. Secondary outcomes included risk factors, complications, and postoperative interventions.

LanguageEnglish

CategoryHealthcare

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Pages10

Reading Time25 min

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Abstract

Introduction

Methods

Results

Conclusion

Clinical significance

Keywords

ORIGINAL ReseARch Surgical Outcome Comparison of Open ConjunctivalAb Externo Xen 45 Gel Stent Implantation vs Trabeculectomy in Open-angle Glaucoma Serina S Applebaum1, Addiskidan Hundito2, Christopher C Teng3, Soshian Sarrafpour4, Ji Liu5 Received on: 20 December 2024; Accepted on: 20 September 2025; Published on: 15 December 2025 AbstrAct Aim: To evaluate the safety, efficacy, and risk factors for failure compared between trabeculectomy and open conjunctival ab externo Xen 45 gel stent (XGS AEO) placement. Methods: For this retrospective single-center study, we included eyes of patients >18 years old with open-angle glaucoma and baseline intraocular pressure (IOP) >17 mm Hg who received trabeculectomy or XGS AEO placement. We excluded aphakic eyes and those missing preoperative data. The primary outcome was the rate of success (6 ≤ IOP ≤ 21 mm Hg, plus ≥20% IOP reduction from baseline, with or without ocular hypotensive medications) after 1 year, compared between groups. Alternative IOP upper limits were 18 and 15 mm Hg. Secondary outcomes were risk factors for failure, complications, and postoperative interventions. Results: We studied 82 trabeculectomy eyes and 34 XGS AEO eyes. At 1 year, 62%, 61%, and 49% of trabeculectomy eyes and 72%, 69%, and 31% of XGS AEO eyes achieved success using IOP upper limits of 21, 18, and 15 mm Hg, respectively. There were no 1-year intergroup differences in IOP, IOP percent change, visual acuity, complications, or revision surgeries. Medication use was higher intheXGS AEO group. Prior trabeculoplasty was associated with a lower risk for failure in the XGS AEO group, but an increased risk in the trabeculectomy group. More eyes in the trabeculectomy group underwent manipulations postoperatively (p = 0.020) . Conclusion: Open conjunctival ab externo Xen placement is similar in efficacy and safety to trabeculectomy. Clinical significance: The similar outcomes and fewer postoperative manipulations of XGS AEO implantation compared to trabeculectomy make it a reasonable surgical option in open-angle glaucoma. Keywords: Ab externo gel stent, Cohort study, Glaucoma surgery, Microinvasive glaucoma surgeries, Refractory glaucoma, Trabeculectomy. Journal of Current Glaucoma Practice (2025): 10.5005/jp-journals-10078-1493 IntroductIon Globally, glaucoma is a major cause of irreversible visual loss, responsible for blindness in approximately 5.2 million people, or 15% of total world blindness.1 For refractory cases requiring surgery, trabeculectomy remains the reference standard treatment for glaucoma, though care has evolved in recent years with the introduction of microinvasive glaucoma surgeries (MIGS), designed with the intention to provide simpler, safer, and more reliable surgical options.2 In particular, the Xen 45 gel stent (Allergan, Inc., Dublin, Ireland) is a crosslinked porcine gelatin tube that was designed for ab interno placement, forming a path between the aqueous and subconjunctival space, thus draining aqueous humor to decrease intraocular pressure (IOP).2 The ab interno Xen approach has been evaluated individually and compared directly to trabeculectomy, with similar rates of failure and comparable reductions in IOP and use of ocular hypotensive drugs, but a better safety profile.3–7 Despite the original ab interno design, there are several compelling reasons to consider an abexterno approach. Abexterno placement facilitates a more predictable direction of the outflow of aqueous humor than ab interno, because Tenon’s capsule and conjunctiva can be directly visualized and positioned.8–10 Additionally, in some cases, prior surgery or difficult facial anatomy may complicate ab interno placement. Furthermore, ab externo placement can avoid corneal incisions and the use of viscoelastic, 1,2Yale University School of Medicine, New Haven, Connecticut, United States 3–5Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven

FAQs

What was the study’s primary objective?

To compare the safety, efficacy, and failure risk factors between trabeculectomy and open conjunctival ab externo Xen 45 gel stent placement.

How was success defined at 1 year?

Success required IOP within specified ranges (6–21 mm Hg) plus at least a 20% IOP reduction from baseline, with or without ocular hypotensive medications.

What were the key findings regarding outcomes between groups?

At 1 year, success rates were similar between groups across IOP thresholds, with no intergroup differences in IOP, visual acuity, complications, or revision surgeries; medication use was higher in the Xen 45 group and trabeculectomy had more postoperative manipulations.

Sep 30, 2026

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