Selective Laser Trabeculoplasty in Open-Angle Glaucoma and Ocular Hypertension: A Narrative Review of Current Evidence

Selective laser trabeculoplasty (SLT) has emerged as a primary or adjunctive treatment choice for lowering intraocular pressure (IOP) in open-angle glaucoma (OAG) and ocular hypertension (OHT), addressing limitations of long-term topical therapy such as adherence challenges and cumulative ocular surface burden. This narrative review synthesizes current evidence on the mechanisms, efficacy and durability, safety, re-treatment, and predictors of response for SLT, with additional focus on treatment parameters (180° vs. 360°), emerging laser modalities (automated direct SLT/DSLT and micropulse laser trabeculoplasty/MLT), and economic and real-world effectiveness considerations. Mechanistically, SLT is based on selective photothermolysis of pigmented trabecular meshwork cells, aiming to minimize collateral structural damage and thereby support repeatability. Clinical outcomes from high-quality randomized evidence—most prominently the LiGHT program—demonstrate that SLT-first strategies achieve IOP control comparable to initial eye drops, with important patient-centered benefits including greater “drop-free” persistence, reduced medication burden, and lower need for incisional surgery over extended follow-up. However, durability attenuates over time in both trial and real-world settings, and long-term control may require escalation or re-treatment. The safety profile is characterized mainly by expected transient anterior segment inflammation and early IOP spikes, while rare vision-relevant complications (e.g., cystoid macular edema) have been reported, particularly in higher-risk clinical contexts such as prior intraocular surgery. Evidence supports meaningful repeatability, with a second SLT session showing the strongest support; data beyond later cycles remain more limited. Across studies, baseline IOP is the most consistent predictor of success, while factors such as fellow-eye response and trabecular angle pigmentation may influence both effectiveness and spike risk. Comparative evidence suggests that 360° SLT generally provides stronger early IOP reduction than 180° SLT, with differences becoming less consistent over longer follow-up. Emerging modalities may improve workflow efficiency (DSLT) and procedural tolerability (MLT), though larger datasets and longer-term durability evidence are still needed. Finally, cost-effectiveness analyses—especially when SLT is used as first-line therapy—support favorable economic outcomes driven by reduced or delayed ongoing medication use. Overall, SLT is well positioned as a cornerstone of modern glaucoma care, with optimal outcomes dependent on appropriate patient selection, parameter choice, risk-adapted follow-up, and safe re-treatment planning.