PreserFlo MicroShunt versus trabeculectomy: an updated meta-analysis and systematic review

PurposeThis meta-analysis compares PreserFlo (PF) and trabeculectomy (TB) in moderate-to-advanced glaucoma (defined by visual fields with a mean deviation (MD) worse than -6 dB). Key outcomes include success rates (qualified success is defined as a target IOP of less than 21 mm Hg or a 20% reduction from baseline at the endpoint, with or without medications. Complete success is achieving these targets without any medications), intraocular pressure (IOP), complications, reinterventions, needling, glaucoma medication reduction, retinal nerve fibre layer (RNFL), and visual field progression.MethodsWe searched PubMed, Scopus, and Cochrane Central up to 13/01/24, including randomized and non-randomized studies with at least 2 months follow-up. Bias risk was assessed using ROB-2 for RCTs and ROBIN-I for non-RCTs. Publication bias was evaluated via funnel plots and Egger's regression.ResultsTen studies (n = 1833 eyes; 57.4% PF) were analyzed. Preoperative IOP was 22.1 mmHg; 56.1% had moderate-to-severe glaucoma. No significant differences were found in qualified (QSR) and complete success rates (CSR) between PF and TB. Trabeculectomy achieved better IOP outcomes (mean difference, MD 1.59 mmHg; p = 0.0004) and greater IOP reduction (MD -2.52 mmHg; p = 0.0003), but PF showed less visual field progression (MD -1.21; p = 0.03) and lower hypotony maculopathy risk (OR 0.30; p = 0.03). PF had a higher reintervention rate, particularly in patients without prior glaucoma surgery (OR 1.74; p = 0.02) or with primary open-angle glaucoma (OR 1.84; p = 0.04).ConclusionTrabeculectomy is more effective for uncontrolled glaucoma up to 2 years, while PF presents a lower risk of hypotony-related events and may benefit patients sensitive to visual field progression. Study strengths include detailed subgroup analyses and mid-term follow-up, with limitations noted in the number of RCTs.Key messagesWhat is knownPreserFlo MicroShunt has been shown to provide an efficient surgical solution for intraocular pressure (IOP) control with a favourable safety profile. Compared to trabeculectomy thereis still contentious regarding the best surgical approach.What is newTrabeculectomy is more effective in uncontrolled glaucoma patients up to 2 years, particularly if lower target IOPs are considered. PreserFlo had lower hypotony-related events risk and may be preferred for patients sensitive to visual field loss.PreserFlo showed a higher risk of reintervention, especially without prior glaucoma surgery or primary open-angle glaucoma diagnosis.Key messagesWhat is knownPreserFlo MicroShunt has been shown to provide an efficient surgical solution for intraocular pressure (IOP) control with a favourable safety profile. Compared to trabeculectomy thereis still contentious regarding the best surgical approach.What is newTrabeculectomy is more effective in uncontrolled glaucoma patients up to 2 years, particularly if lower target IOPs are considered. PreserFlo had lower hypotony-related events risk and may be preferred for patients sensitive to visual field loss.PreserFlo showed a higher risk of reintervention, especially without prior glaucoma surgery or primary open-angle glaucoma diagnosis.