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Multicenter Study
. 2025 Apr 1;34(4):330-341.
doi: 10.1097/IJG.0000000000002543. Epub 2025 Jan 29.

One-Year Real-World Outcomes of Ab-Externo Gel Stent Placement From the EXPAND Study

Brian A Francis  1 , Vanessa Vera  2 , Joshua Kim  3 , Mahdi M Basha  4 , Bryant Lum  5 , Douglas Grayson  6 , Steven Vold  7 , Mini Balaram  2 , Susan Simonyi  8 , Husam Ansari  9 , Natasha Nayak Kolomeyer  10
Affiliations
Multicenter Study

One-Year Real-World Outcomes of Ab-Externo Gel Stent Placement From the EXPAND Study

Brian A Francis et al. J Glaucoma. .

Abstract

Prcis: In the real-world, retrospective, EXPAND study of consecutive adults with glaucoma, ab-externo gel stent implantation effectively lowered intraocular pressure (34%) and the medication burden (61%), with transient/self-resolving hypotony as the most frequent adverse event (28%).

Purpose: To assess effectiveness and safety of ab-externo gel stent (GS) implantation in glaucoma.

Methods: Multicenter, real-world, retrospective study. Consecutive adults with glaucoma and ab-externo GS implantation (with/without phacoemulsification or open/closed conjunctiva) ≥12 months before study entry. Data were extracted between the baseline/preoperative and last follow-up visit or date of secondary surgical intervention (SSI). Primary effectiveness endpoint: proportion of primary eyes (first eye in bilaterally implanted patients) at month 12 (M12) achieving ≥20% intraocular pressure (IOP) reduction from baseline without medication increase, clinical hypotony, vision loss to counting fingers, or SSI. Secondary effectiveness endpoints included complete success (IOP ≤18 mm Hg and ≥20% IOP reduction from medicated baseline without medication, clinical hypotony, or SSI); qualified success (same but without medication increase); and needling rate. Key safety endpoints (all eyes): intraoperative complications, postoperative adverse events (AEs), and SSIs.

Results: The safety population included 466 eyes; 80.7% received the GS alone and 85.0% were implanted with closed conjunctiva. At M12, 39.1% of all primary eyes (N=413) and 54.9% of primary eyes with IOP and medication data at baseline and M12 (N=213) achieved the primary endpoint. At M12 among all primary eyes, the complete success, qualified success, and needling rates were 33.5%, 56.5%, and 28.6%. Most eyes (97.9%) had no intraoperative complications. The most frequent postoperative AE was transient/self-resolving hypotony (IOP <6 mm Hg; 28.1%). Sixty-nine (14.8%) eyes required an SSI.

Conclusions: Ab-externo GS placement effectively lowered IOP and the medication count without unexpected complications/AEs, expanding implantation options based on patients' needs and surgeons' preferences.

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Conflict of interest statement

Disclosure: Financial arrangements of the authors with companies whose products may be related to the present report are listed as declared by the authors. B.A.F. has served as a consultant for Allergan (an AbbVie company), Bausch+Lomb, BVI Endo Optiks, iStar, Ivantis, MST, and Thea, and is a speaker for Aerie Pharmaceuticals. V.V. is an employee of Allergan (an AbbVie company) and may hold AbbVie stock. J.K. has served as speaker and/or consultant/advisor for Alcon, Allergan (an AbbVie company), Bausch+Lomb, and Glaukos. M.M.B. has received research support from AbbVie, Alcon, Formosa Pharmaceutical, Glaukos, Ivantis, Novartis, and Ocular Therapeutix, and is a speaker for AbbVie and Alcon. B.L. has no disclosures to declare. D.G. has served as speaker and/or consultant/advisor to Allergan (an AbbVie company), Alcon, Johnson & Johnson, Glaukos, and New World Medical. S.V. is a consultant/advisor for Aerie Pharmaceuticals, Alcon, Allergan (an AbbVie company), Bausch+Lomb, Carl Zeiss Meditec, Glaukos, Iridex, iStar Medical, Ivantis, Sight Sciences, and Volk Optical; has received grant support from Santen, and is an equity owner of Alphaeon, Ivantis, and O3 Optix. M.B. is a current employee of Nethra Consulting LLC but was an employee of Allergan (an AbbVie company) at the time the study was conducted and may hold AbbVie stock. S.S. is a consultant for Innomar Strategies but was an employee of Allergan (an AbbVie company) at the time the study was conducted and may hold AbbVie stock. H.A. has received consulting honoraria from Allergan (an AbbVie company) and Ivantis, and research support from Allergan (an AbbVie company), Ivantis, and New World Medical. N.N.K. has received research support from Allergan (an AbbVie company), Aerie Pharmaceuticals, Diopsys, Equinox, Glaukos, Guardion Health Sciences Inc, Nicox, Olleyes, and Santen, and is a consultant to Allergan (an AbbVie company); spouse is a consultant for Alimera, Allergan (an AbbVie company), Biogen, Genentech, Iveric, Regeneron, and Vial.

Figures

FIGURE 1
FIGURE 1
Patient disposition. aEffectiveness population, which included all primary eyes (ie, first eyes implanted in case of bilateral implantation). bSafety population, which included all primary and secondary eyes. cIncluded covid-related reasons (n=19), no 12-month visit within the defined window (n=6); debt (n=1), progression to no light perception due to a serious adverse event that prevented data collection (n=1), gel stent not functioning/no visual potential (n=1), not documented (n=28). Phaco indicates phacoemulsification.
FIGURE 2
FIGURE 2
Proportion of primary eyes that, at month 12, achieved the primary effectiveness endpoint, that is, ≥20% IOP reduction from baseline without IOP-lowering medication increase, clinical hypotony (defined in the Methods), vision loss to counting fingers, or secondary surgical intervention. A, The overall population of primary eyes that had both IOP and medication count data at baseline and any postoperative visit. The total N (299) at 12 months is greater than that in Figure 1 because eyes that underwent/experienced removal, repositioning, or migration of the gel stent, or secondary surgical intervention were included as failures in this analysis, despite having discontinued the study. B, Subpopulation of primary eyes that had both IOP and medication count data at both the baseline and 12-month visits. An exception was made to include ≤21 observations obtained after 60 weeks in the 12-month window, due to COVID-19. IOP indicates intraocular pressure; N, total number of eyes providing data; n, number of eyes achieving the effectiveness endpoint; phaco, phacoemulsification.
FIGURE 3
FIGURE 3
Mean and changes in mean IOP and mean topical IOP-lowering medication count over time in primary eyes overall. The bars represent mean IOP±SD. The numbers in parentheses represent the change in mean IOP from baseline. An exception was made to include 21 (IOP-related) and 19 (medication-related) observations obtained after 60 weeks in the 12-month window, due to COVID-19. aIn the medication analysis, 1 additional eye was included in the implant alone subgroup and total population at months 3, 6, 9, and 12. IOP indicates intraocular pressure; meds, medications; phaco, phacoemulsification.
FIGURE 4
FIGURE 4
The proportion of overall primary eyes achieving prespecified levels of IOP without clinical hypotony (defined in the Methods). An exception was made to include 20 observations obtained after 60 weeks in the 12-month window, due to COVID-19. IOP indicates intraocular pressure; N, total number of eyes providing data; n, number of eyes achieving the effectiveness endpoint; phaco, phacoemulsification.
FIGURE 5
FIGURE 5
The proportion of overall primary eyes achieving complete and qualified success (as defined in the Methods). An exception was made to include 19 observations obtained after 60 weeks in the 12-month window, due to COVID-19. N indicates total number of eyes providing data; n, number of eyes achieving the effectiveness endpoint; Phaco, phacoemulsification.
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