Risk Factors for Failure in Glaucoma Patients undergoing Microshunt Implantantion

PURPOSE: Evaluate risk factors for failure of Microshunt in glaucoma patients.

DESIGN: Multicenter retrospective cohort study.

METHODS:250 eyes from 220 consecutive glaucoma patients undergoing Microshunt implantation at six glaucoma units. We defined four intraocular pressure (IOP) success criteria: A) IOP <21mmHg with 20% IOP reduction; B) IOP <18mmHg with <20% IOP reduction; C) IOP <15mmHg with <25% IOP reduction; and D) IOP <12mmHg with <30% IOP reduction from baseline. Kaplan-Meier analysis estimated success rates according to the criteria above, and multivariable Cox models identified risk factors for failure according to criterion A.

RESULTS: Success rates varied based on different criteria, ranging from 43.3% to 62.5% (overall success for criteria D and A, respectively) and from 35.3% to 44.4% (complete success for criteria D and A, respectively) at 1-year follow-up. Higher intraoperative MMC concentration was associated with reduced risk of failure to maintain complete (0.4 vs 0.2 mg/mL: Hazard ratio [HR]: 0.441, p<0.001) and overall (0.4 vs 0.2 mg/mL: HR: 0.360, p=0.004) success. For complete success, other risk factors for failure were pseudoexfoliation glaucoma/pigmentary glaucoma (HR: 1.641, p=0.004), primary angle closure glaucoma (HR: 1.611, p<0.001), and previous non-glaucomatous ocular surgeries (HR: 2.301, p=0.002). For overall success, other risk factors for failure were lower preoperative IOP (for 1-mmHg increase, HR: 0.934, p=0.005), higher number of preoperative antiglaucoma agents (HR: 1.626, p<0.001), and Microshunt combined with cataract surgery (HR: 1.526, p=0.033).

CONCLUSIONS: This study identified risk factors for Microshunt failure, highlighting the importance of high intraoperative MMC dose and careful patient selection to optimize surgical success.

Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.

Authors: Alessandro Rabiolo MD, FEBO , Rebecca Toscani , Matteo Sacchi MD , Pietro Destefanis MD , Paolo Bettin MD , Carlo Ciampi MD , Antonella Clemente MD , Carlo Alberto Cutolo MD, FEBO , Karl Mercieca MD, FRCOphth , Michele Iester MD , Carlo Enrico Traverso MD, FARVO , Marco Di Maita MD, FEBO , Gaia Li Calzi MD , Paolo Nucci MD , Francesco Bandello MD, FEBO , Giacinto Triolo MD, FEBO , Stefano De Cill `a MD

NGP Papers manager: Carlo Cutolo