Author’s Disclosure Block: David Yan: Alcon, Employment/honoraria/consulting fees, Abbvie, Employment/honoraria/consulting fees, Bausch & Lomb, Employment/honoraria/consulting fees, J & J Vision, Employment/honoraria/consulting fees; Anna Huixin Zhang: none; Eric Yixiao Cao: none; Esther Wong: none; Iqbal Ike Ahmed: Consultant for: 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. Research grants from: Abbvie, Alcon, Bionode, Carl Zeiss, CorNeat Vision, Elios Vision, Glaukos, Gore, iCare, iStar, Johnson & Johnson Vision, Myra Vision, New World Medical, Santen.

Abstract Body
ObjectivesTo determine the 12-month effectiveness and safety profile of the SIBS Microshunt implanted with an intraluminal rip-cord suture to mitigate early hypotony in refractory eyes. Study Design: Single center, consecutive, retrospective cohort study. Methods: Consecutive eyes with a history of failed incisional glaucoma surgery underwent SIBS Microshunt implantation via an open-conjunctiva, ab-externo approach, with or without phacoemulsification. A 10-0 nylon suture was inserted 4 mm into the lumen of the microstent to mitigate early hypotony by increasing microstent flow resistance. The ripcord was secured into the limbal cornea for easy removal at the slit lamp, usually by 2-3 weeks postoperatively when IOP had risen to > 12 mmHg with no hypotony-related complications present. Primary outcome was complete success, defined as no two consecutive IOP readings >17mmHg or <6mmHg and a 20% intraocular pressure (IOP) reduction on no medication. Secondary outcomes were hypotony rates, change in IOP/medication use, post-operative intervention rates, and complications. Results: Fifty-nine refractory eyes included in the study had a mean baseline IOP of 22.3 ± 5.2mmHg (n=59, 95% CI: 20.9-23.6 mmHg), and baseline glaucoma medication classes of 3.64 ± 0.83 (95% CI: 3.43-3.85). 6.78% of cases were combined with phacoemulsification. At 12-months postoperatively, complete success was achieved in 74.6% of the refractory eyes. Mean IOP was 12.7 ± 4.5 mmHg (n=27, 95% CI:11.0-14.4, p<0.00001), and final medication was 0.56 ± 1.12 (n=35, 95% CI: 0.13-0.98, p<0.00001). Early transient hypotony (<3 months) occurred in 35.1% (n=20), of which 28.1% (n=16) occurred before the rip-cord suture was pulled and 4 afterwards (7.0%). The ripcord was removed post-operatively as per protocol (IOP > 12 mmHg) in all cases by 3-months. Bleb needling rate was
5.3%. Choroidal effusion/folds occurred in 31.6% of patients and spontaneously resolved by 3 months without intervention. Conclusions: Implantation of SIBS Microshunt with an ab-externo approach combined with a rip-cord suture technique achieved a high success and is effective at reducing IOP and medication use after 1-year follow-up in refractory eyes. SIBS Microshunts may be a viable alternative to traditional tube shunt surgery after the initial glaucoma filtering procedure has failed.