What is the Long-Term Efficacy and Safety of Selective Laser Trabeculoplasty in the Management of Primary Open-Angle Glaucoma? A Systematic Review and Meta-Analysis

Selective laser trabeculoplasty (SLT) is a laser-based intervention used to lower intraocular pressure (IOP) in patients with primary open-angle glaucoma (POAG). It has been adopted as both a primary and adjunctive therapy, with growing interest in its long-term outcomes. This systematic review and meta-analysis aimed to assess the long-term efficacy and safety of SLT in adult patients with POAG, with a focus on sustained IOP control, reduction in medication burden, preservation of visual function, and adverse event incidence. This review was conducted in accordance with PRISMA 2020 and MOOSE guidelines and was prospectively registered in PROSPERO (CRD420251030192). A systematic literature search was performed on June 16, 2025, across PubMed, Embase, Medline, and Scopus, including all records from database inception to the search date. Randomized controlled trials and observational studies reporting SLT outcomes with a minimum follow-up duration of 12 months were included. Primary outcomes included long-term IOP reduction and SLT failure rates. Secondary outcomes included medication use, visual field changes, and adverse events. Study quality was assessed using ROB-2 and Newcastle-Ottawa tools. Data were synthesized using random-effects models, and inter-study heterogeneity was quantified using the I² statistic. From 3,462 identified records, 60 clinical studies were included for qualitative synthesis and 50 were included in the meta-analysis, representing a pooled sample of 8,934 eyes. SLT achieved IOP reduction comparable to topical medications at 6-12 months post-treatment (mean difference: 0.04 mmHg; 95% CI: -0.27 to 0.34). Medication use significantly decreased following SLT (mean reduction: -0.87 medications; 95% CI: -1.13 to -0.62). Visual field mean deviation improved by 0.79 dB (95% CI: 0.76 to 0.82), and SLT was associated with minimal short-term IOP spikes. The health-related quality-of-life scores, as measured by EQ-5D, showed modest but consistent improvements. Risk of bias and publication bias were low in most domains. SLT demonstrated sustained long-term efficacy in reducing intraocular pressure and minimizing pharmacological burden in patients with POAG. It maintained visual function over extended follow-up and was associated with a favorable safety profile, including a low incidence of adverse events and IOP spikes. These findings support the use of SLT as an effective and safe long-term management option for POAG and justify its consideration as a first-line or adjunctive therapy in clinical practice.