Author’s Disclosure Block: Iqbal Ike Ahmed: AbbVie, Ace Vision, Alcon, Aliph Medical, Aquea Health, ArcScan, Avellino Lab, Avisi, Balance Ophthalmics, Bausch and Lomb, Beaver Visitec, Belkin Vision, Bionode, Carl Zeiss, Centricity Vision, CorNeat Vision, Custom Surgical, Elios Vision, ElutiMed, eyeFlow, Eye to Eye TeleHealth, EyeMed, EyeQ Technologies, Exhaura Limited, Glaukos, Gore, Hexiris Pharma, Iantrek Inject Sense, Iridex, iCare, iStar, Johnson & Johnson Vision, LayerBio, Liqid Medical, Long Bridge Medical, Medicontur, MST Surgical, Myra Vision, New World Medical, Nova Eye, Ocular Instruments, Ocular Therapeutix, Oculus Surgical, OcuSciences, Omega Ophthalmics, Peripherex, PolyActiva, PulseMedica, Radiance Therapeutics, Radius XR, Rheon Medical SA, Ripple Therapeutics, Sanoculis, Santen, Singapore Biodesign, Shifamed, Sight Sciences, Smartlens, Stroma, Thea Pharma, TFS Health Science, ViaLase, Visci Ltd, Visus Therapeutics, Vizzario, Zilia, Employment/honoraria/consulting fees, Abbvie, Alcon, Bionode, Carl Zeiss, CorNeat Vision, Elios Vision, Glaukos, Gore, iCare, iStar, Johnson & Johnson Vision, Myra Vision, New World Medical, Santen, Grant/research support; Anna Huixin Zhang: none; Ticiana De Francesco: Allergan: Speaker Zeiss: Consultant Glaukos: Consultant Elios: Consultant Iantrek: Consultant Santen: Speaker Sight Sciences: Consultant ViaLase: Consultant Myra: Consultant Nova Eye Medical: Consultant

Abstract Body
Purpose: To compare the effectiveness and adverse event profile of standalone 63-μm gelatin microstent versus SIBS microshunt implantation Study Design: Single center, consecutive, retrospective cohort study. Methods: Consecutive eyes that underwent 63-μm gelatin microstent implantation with MMC were compared with eyes that underwent SIBS microshunt implantation with MMC. Primary outcome: complete success, defined as no two consecutive IOP readings >17mmHg or <6mmHg with >2 lines of vision loss and a 20% IOP reduction on no medication. Secondary outcomes: IOP thresholds (14mmHg, 21mmHg), qualified success, change in IOP/medication use, complications, and re-operations. Cox proportional hazards modeling was used to assess risk factors for failure. Results: At 1-year follow-up, complete success was achieved in 61.3% of the gelatin microstent group versus 75.5%% of the SIBS microshunt group (p=0.020). Qualified success was also higher in the SIBS microshunt group (95.3%% vs. 86.8%, p=0.153). Cox analyses identified the gelatin microstent as a significant risk factor for failure (HR: 1.85, 95% CI: 1.20-2.85, p=0.006). Needling rates were similar between groups (7.9% vs. 8.7%, p>0.99), but bleb revision was more frequent in the gelatin microstent group (14.3% vs. 3.7%, p=0.0168). Early complications, as choroidals, were more frequent in the gelatin microstent group ( 22.5% vs. 7.4%, p<0.001). Conclusion: Both the 63-μm gelatin microstent and the SIBS microshunt demonstrated significant IOP and medication reduction, with the last one demonstrating a higher success rate and less need for surgical revision.