Conclusions: 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%).

Objective: 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.