Efficacy and safety of PreserFlo MicroShunt versus trabeculectomy in glaucoma patients: a systematic review, meta-analysis, and meta-regression of clinical outcomes and key covariates

Abstract

PreserFlo MicroShunt (a subconjunctival drainage device classified as minimally invasive bleb surgery [MIBS]) has been adopted as a less invasive alternative to trabeculectomy, but comparative evidence across clinical outcomes and safety profiles remains heterogeneous. We synthesized current comparative data on efficacy and complications and explored key covariates using meta-regression. Systematic Review and Meta-Analysis. We conducted a PRISMA-compliant systematic review of PubMed, Embase, and Scopus from inception through December 2025. Comparative studies of PreserFlo versus trabeculectomy reporting extractable outcomes were included. Random-effects meta-analyses were performed for continuous outcomes (mean difference, inverse-variance) and dichotomous outcomes (odds ratio, Mantel–Haenszel). Meta-regression evaluated prespecified covariates (e.g., age, baseline IOP, medication burden, pseudophakia, prior surgery, follow-up). Sensitivity analyses (leave-one-out) and publication-bias assessments (funnel plots/Egger) were performed. Fourteen studies (2,229 patients; follow-up 2–24 months) were included. Compared with trabeculectomy, PreserFlo was associated with higher postoperative IOP (MD 1.44 mmHg; 95% CI 0.64–2.24) and smaller IOP reduction (MD − 2.73 mmHg; 95% CI − 3.84 to − 1.61), with moderate-to-high heterogeneity. Rates of complete and qualified success were similar between procedures (OR 0.95 and 0.97, respectively). PreserFlo was associated with lower odds of hypotony maculopathy (OR 0.31; 95% CI 0.12–0.78) and fewer overall postoperative complications (OR 0.48; 95% CI 0.38–0.60). Evidence of small-study effects was observed for selected outcomes. PreserFlo demonstrates similar surgical success rates to trabeculectomy but provides less overall IOP reduction, while showing a more favorable complication profile, particularly regarding hypotony maculopathy and overall postoperative events.