Intraocular Pressure and Medication Changes Associated with Xen Gel Stent: A Systematic Review of the Literature

Abstract

The Xen gel stent (Allergan Inc, an AbbVie company; Dublin, Ireland) was conceived as an option for patients requiring modest IOP reduction but for whom trabeculectomy was not yet indicated. As with any glaucoma surgery, establishing criteria for patient selection and identifying factors that contribute to a high likelihood of success are important. To help guide clinical decision-making, a systematic review of published studies on the gel stent was performed, with the goal of understanding postoperative outcomes based on clinical and patient factors. Results were organized around a series of pertinent clinical questions based on scenarios encountered in clinical practice. Criteria for including studies were intentionally broad, with the objective of simulating the diverse population of glaucoma patients encountered in real-world practice. Outcomes for IOP and medication reduction postoperatively were assessed in various analyses, including in eyes with various glaucoma types and severity; in eyes naïve to surgery as well as those with a history of prior incisional glaucoma surgery; and when surgery was performed as a standalone procedure or at the time of cataract surgery. The results of each of the various analyses were consistent in demonstrating that successful gel stent surgery achieved a postoperative IOP of approximately 14.0 mm Hg and reduction to fewer than 1 glaucoma medication. Additional data are shown on outcomes by method of implant (ab interno vs ab externo); intraoperative use of antifibrotics; and rates of needling in published studies.

Keywords:

• glaucoma
• glaucoma surgery
• bleb
• Xen
• gel stent

Abbreviations

5-FU, Fluorouracil; HR, hazard ratio; MMC, mitomycin; POAG, primary open-angle glaucoma; PEXG, pseudoexfoliative glaucoma; SSI, secondary surgical intervention.

Data Sharing Statement

Data used for the research described herein was acquired by the authors by searches on publicly available online libraries.

Ethics Approval and Informed Consent

This formulation of this manuscript did not involve research on humans or animals.

Consent for Publication

Consent is not required to publish any information herein.

Acknowledgments

Editorial assistance in the preparation of this article was provided by Bryan Bechtel of Bryn Mawr Communications, LLC. Support for this assistance was funded by Allergan, an AbbVie Company.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

Richard Fiscella is an employee of AbbVie, Inc. and may hold AbbVie stock. Brian A. Francis is a consultant for Allergan/AbbVie, Bausch & Lomb, BVI Endo Optiks, IStar, Ivantis, Iridex, MST, Thea; Speaker for Aerie. Robert J. Noecker reports consulting Fee from Alcon, Aerie, Allergan, Alimera, Beaver-Visitec, Glaukos, Iridex, Ocular Therapeutics, Santen, Thea, Kala, New World Medical, Oysterpoint, Sight Sciences, Science Branding, iStar, MST; Speakers Bureau for Allergan, Alcon, Beaver-Visitec, Iridex, Quantel, Imprimis, Kala, Nova Medical, Sight Sciences; Contracted Research for Allergan, Glaukos, Nova Medical; Equity Owner of Ocular Therapeutics, Tula Medical, ISP Surgical, Mati. Joseph F. Panarelli reports personal fees from AbbVie, Aerie, CorneaGen, Glaukos, Santen, New World Medical, Allergan, Nova Eye Medical, AOI Ophthalmics. Nathan Radcliffe reports personal fees from Alderya, AbbVie, Alcon, Allergan, Alimera, Aerie, Avellino, Bausch & Lomb, Beaver Visitec, Belkin, CATS, Carl Zeiss Meditec, Elios Vision, Equinox, Eyenovia, Eyepoint, Expert Opinion, Glaukos, Imprimis, Iridex, Ivantis, IrisVision, Lumenis, New World Medical, Novartis, Ocular Therapeutix, Regeneron, Reichert, Shire, Sight Sciences, SpyGlass, Tarsus, Thea, Tearclear, ViaLase. Arsham Sheybani is a consultant for Allergan/AbbVie, Alcon, Nova Eye, Santen, New World Medical. Oluwatosin U. Smith is a consultant for Alcon, Allergan, Iridex, Santen, New World Medical, Glaukos; Speaker & consultant for Aerie, Bausch & Lomb; Stocks from Nova Eye Medical. Vanessa Vera is an employee of AbbVie, Inc. and may hold AbbVie stock. The authors report no other conflicts of interest in this work.

Additional information

Funding

This review was supported by Allergan plc, Dublin, Ireland (prior to its acquisition by AbbVie Inc.). The sponsor participated in the writing, reviewing, and approval of the final version of the manuscript. Neither honoraria nor payments were made for authorship.