Factors Associated with Favorable One-Year Outcomes After PreserFlo MicroShunt Implantation: Insights from Anterior Segment Optical Coherence Tomography

INTRODUCTION: This study aimed to identify factors associated with favorable 1-year surgical outcomes after PreserFlo MicroShunt (PMS) implantation, with a particular focus on baseline ocular anatomy and postoperative filtration patterns assessed by anterior segment optical coherence tomography (AS-OCT). METHODS: This cohort study included individuals with primary open-angle or exfoliation glaucoma who underwent PMS implantation. AS-OCT was performed 1 month postoperatively. Surgical success was defined by hypertensive thresholds of 12 mmHg (A), 15 mmHg (B), and 18 mmHg (C), with an intraocular pressure (IOP) reduction of ≥ 20% from baseline. Each criterion had a hypotensive limit of 6 mmHg. Multivariable Cox proportional hazards models were used to evaluate factors associated with favorable outcomes, considering both hypertensive and hypotensive failure limits. RESULTS: Eighty-eight eyes were analyzed. Median IOP decreased from 19 mmHg (interquartile range: 16-23.8) to 10 mmHg (8-13) at 12 months (p < 0.001). Qualified success rates at 12 months were 56.8% for criterion A, 70.5% for criterion B, and 73.9% for criterion C. Filtration toward the corneal limbus on AS-OCT was associated with a lower risk of hypertensive failure across all criteria (HR, 0.28-0.57; p = 0.008-0.031). Longer axial length was significant for criteria B and C (HR, 0.70 and 0.77; p = 0.002 and 0.008). Older age and exfoliation glaucoma were risk factors for hypotensive failure (HR, 1.05 and 3.75; p = 0.01 and 0.006). CONCLUSION: Both baseline ocular anatomy, represented by axial length, and filtration toward the corneal limbus on AS-OCT were independently associated with favorable 1-year outcomes following PMS implantation. Integrating preoperative anatomical assessment with early postoperative imaging findings may help clinicians better understand individual surgical responses.