Risk factors and protective strategies for hypotony following preserflo microshunt implantation

The PreserFlo MicroShunt (PMS) is a minimally invasive surgical device for glaucoma management. However, postoperative hypotony remains a significant complication. This retrospective cohort study analyzed 471 eyes to evaluate the efficacy of PMS implantation in reducing intraocular pressure (IOP) and medication dependency, as well as to identify risk factors associated with hypotony. The median IOP decreased significantly from 19 mmHg preoperatively to 10 mmHg three months postoperatively, with the median medications score dropping to zero. Postoperative hypotony occurred in 18.7% of the cases. Multivariate analysis identified preoperative IOP ≥ 25 mmHg (odds ratio (OR): 2.01, 95% confidence interval (CI): 1.00-4.02, p = 0.049) and medication scores ≥ 5 (OR: 2.12, 95% CI: 1.13-3.96, p = 0.019) as significant risk factors for hypotony, while axial length ≥ 25.5 mm (OR: 0.19, 95% CI: 0.09-0.39, p < 0.001) and intraluminal suture stenting (OR: 0.08, 95% CI: 0.03-0.25, p < 0.001) were significantly protective. Importantly, intraluminal suture stenting mitigated the risk of hypotony without compromising the short-term surgical outcomes. These findings emphasize the need for careful patient selection and the potential of intraluminal suture stenting as an effective intraoperative strategy to improve the safety and outcomes of PMS implantation.