Abstract
PURPOSE: The Preserflo-MicroShunt (PF) is an established device for treating glaucoma, effectively reducing intraocular pressure (IOP) with a good safety record. However, its efficacy in eyes with significantly elevated preoperative IOP levels is not well-documented due to exclusion from many clinical studies. This study aims to evaluate PF outcomes in eyes with highly increased IOP and compare them with those having moderately increased levels. METHODS: Retrospectively, eyes diagnosed with primary open angle glaucoma (POAG) or pseudoexfoliation glaucoma (PXG) undergoing PF were analysed. They were categorized into two groups: highly increased IOP (HI-IOP, ≥30 mmHg) and moderately increased IOP (MI-IOP, ≤25 mmHg). IOP, number of IOP lowering medications (NoM), success rates (SR), and postoperative complications were compared at 1, 3, 6, and 12 months. RESULTS: One year postoperatively, IOP was reduced from 39.0 ± 7.4 mmHg to 14.4 ± 4.4 mmHg in the HI-IOP and from 19.5 ± 3.6 mmHg to 14.0 ± 4.5 mmHg in the MI-IOP group. NoM decreased significantly in both groups (p < 0.001 for all). Success rates did not differ between groups during the first year (p > 0.05 in all subgroups). However, the HI- IOP group had higher rates of persistent hypotony (7% vs. 0%, p = 0.02) and tendentially higher rates of choroidal detachment (23% vs. 11%, p = 0.08). Other adverse events were rare and comparable. Further glaucoma surgery was required in 26% and 19% of cases, respectively (p = 0.41). CONCLUSION: PF appears to be a suitable option for managing both highly and moderately increased IOP levels in POAG and PXG eyes, with comparable outcomes up to 12 months following surgery.