Influence of intraluminal stent placement on 18-month outcomes of Preserflo MicroShunt in Japanese patients with open-angle glaucoma

Purpose To compare the efficacy of the PreserFlo MicroShunt (PMS) at 18 months in Japanese patients with primary open-angle glaucoma (POAG) and exfoliation glaucoma (EXG) between eyes with preoperative intraocular pressure (IOP) < 15 mmHg (low-tension glaucoma [LTG] group) and ≥ 15 mmHg (high-tension glaucoma [HTG] group), and to evaluate the impact of intraluminal stent removal timing on postoperative surgical outcomes. Study design Retrospective clinical investigation. Methods Records of all POAG and EXG patients undergoing PMS at Kochi University Hospital (June 2023–June 2024) were reviewed. Eyes were categorized by preoperative IOP (LTG/HTG) and by stent use: no stent (NST), stent removal at days 1–7 (ST1), days 8–14 (ST2), and day 15 or later (ST3). Results The study included 75 HTG and 49 LTG eyes. At 18 months, IOP decreased significantly in both HTG (20.5 ± 4.9 to 12.2 ± 3.3 mmHg, P < 0.001) and LTG groups (12.4 ± 1.8 to 10.9 ± 2.5 mmHg, P = 0.037). Medication scores decreased significantly in both groups ( P < 0.001). Hypotony rates were lower in the ST2 (9.5%) and ST3 (16.3%) groups than in the NST (65.2%) and ST1 (38.7%) groups. Stent retention did not adversely affect IOP at 18 months. Conclusion Although surgical success was significantly lower in LTG than in HTG, PMS significantly reduced IOP in Japanese patients with both POAG and EXG at 18 months. Additionally, retaining the intraluminal stent for more than 1 week reduced hypotony risk without adversely affecting postoperative IOP.