Bleb Needling Efficacy and Outcomes in Novel Subconjunctival Glaucoma Surgeries

Author Block: Anastasiya Vinokurtseva , Lorenz Kuske, Matthew B. Schlenker, Iqbal Ike Ahmed.  Prism Eye Institute; University of Toronto.

Author Disclosure Block: A. Vinokurtseva:  None.  L. Kuske:  None.  M.B. Schlenker:   Any direct financial payments including receipt of honoraria; Name of for-profit or not-for-profit organization(s); Santen Pharmaceutical Co., Ltd, Alcon, Aequus Pharmaceuticals, Johnson & Johnson Vision, Labtician Thea, Light Matter Interaction Inc. Any direct financial payments including receipt of honoraria; Description of relationship(s); Consultant fees, honoraria.  I. Ahmed:   Any direct financial payments including receipt of honoraria; Name of for-profit or not-for-profit organization(s); Aequus, Ace Vision, Aerie Pharamceuticals, Akorn, Alcon, Allergan, Aquea Health Inc, ArcScan, Avellino Lab USA Inc, Avisi, Bausch Health, Beaver Visitec, Beyeonics, Bionode, Carl Zeiss Meditec,, Centricity Vision Inc, CorNeat Vision, Custom Surgical, Elios Vision, ElutiMed, Equinox, eyeFlow Inc, Exhaura Ltd, Genentech, Glaukos, Gore, Heine, Heru, Iantrek, InjectSense, Iridex, iCare, iStar,, Ivantis, Johnson & Johnson Vision, Labtician Thea, LayerBio, Leica Microsystems, Life Long Vision, Long Bridge Medical Inc, MicroOptx, MST Surgical, Myra Vision, New World Medical, NovaEye,, Ocular Insturments, Ocular Therapeutix, Oculo, Oculus Surgical, Omega Ophthalmics, PolyActiva, PulseMedica, Radiance Therapeutics Inc, Ripple Therapeutics, Sanoculis, Santen, Shifamed LLC,, Sight Sicences, Smartlens Inc, Stroma, Thea Pharma, ViaLase, Visus Therapeutics, Vizzario, VSY Biotechnology, Zilia Inc. Any direct financial payments including receipt of honoraria; Description of relationship(s); Consultant Fees, Speakers Honoraria, Research Support.

Abstract Title: Bleb Needling Efficacy and Outcomes in Novel Subconjunctival Glaucoma Surgeries

Abstract Body: Purpose:  Needling can rescue a failing filtering bleb and improve success rates after subconjunctival glaucoma filtration surgery (GFS). However, the relative efficacy of performing this procedure after novel subconjunctival microshunt implantation has not been extensively studied. The current study compared needling efficacy between patients who had received SIBS microshunt, gel microshunt, or trabeculectomy.   Study Design:  Multicenter, retrospective, interventional cohort study.   Methods:  Consecutive patients undergoing GFS between August 2015 and August 2020 at one of 6 participating international centers were followed for 6 months from the time of needling, which was performed in clinic. Cohorts were divided based on surgery type: SIBS microshunt, gel microshunt, or trabeculectomy. Primary outcome was surgical success, defined as proportion of eyes with (1) no 2 consecutive IOPs >14mmHg or clinical hypotony, without (complete) or with (qualified) glaucoma medications; and (2) ≥20% reduction from baseline IOP. Secondary outcomes included median IOP, medications, risk factors, post-needling interventions, complications, and reoperations.   Results:  Records from 182 eyes that underwent needling after SIBS microshunt (N=84), gelatin microshunt (N=64) and trabeculectomy (N=34) were included. Baseline IOP and disease severity was comparable between the 3 cohorts. SIBS microshunt patients were more likely to be younger (78.7% <70), non-Caucasian (54.3%), to have worse pre-operative visual acuity (66.0% logMAR >0.4), and refractory glaucoma (27.7% had previous subconjunctival GFS). After 6-months follow-up from the time of needling, 65.9% of eyes with SIBS microshunt, 39.1% of eyes with gelatin microshunt and 47.1% of eyes with trabeculectomy achieved complete surgical success. Risk factors significantly associated with failure were diabetes (HR 1.9; 95%CI 1.2-3.0) and IOP at the time of needling >21mmHg (HR 1.6; 95%CI 1.1-2.3). At 6 months post-needling, 53.9% of patients with SIBS microshunt were medication-free, compared to 44.4% with gelatin microshunt patients and 45.5% with trabeculectomy. Complications of any type post-needling occurred in 35.7% of SIBS microshunt patients, 29.7% of gelatin microshunt patients and 29.4% of trabeculectomy patients. Reoperations occurred in 9.5% of patients with SIBS microshunt, 32.8% patients with gelatin microshunt, and 14.7% of trabeculectomy patients.   Conclusions:  Overall, needling is an effective intervention for improving surgical success in GFS, especially in patients with lower IOP at the time of needling and those without diabetes. SIBS microshunt patients experience greater benefit than gelatin microshunt or trabeculectomy patients in terms of surgical success, medication-free survival, and reoperation rates post-needling.