Spotlight on MicroPulse Laser Trabeculoplasty in Open-Angle Glaucoma: What’s on? A Review of the Literature

Outcomes of Micropulse Laser Trabeculoplasty Compared to Selective Laser Trabeculoplasty: A Systematic Review and Meta-Analysis

Purpose

To perform a meta-analysis and systematic review to compare the efficacy and complications of micropulse laser trabeculoplasty (MLT) and selective laser trabeculoplasty (SLT) in adult patients with open-angle glaucoma (OAG) and ocular hypertension (OHT).

Methods

We performed a systematic review utilizing PubMed, Embase, and Scopus, on April 8, 2024. Meta-analyses were performed for the mean change in intraocular pressure (IOP) at one-month, six-month, and one-year follow-up visits, rate of IOP spikes (>5 mmHg increase from the pre-procedure baseline IOP), rate of treatment failure (<20% or <3 mmHg reduction in IOP or requiring additional medications or procedures), and mean change in number of medications.

Results

Six studies, with a total of 593 eyes, were included: 283 underwent MLT, while 310 underwent SLT. A statistically significant difference in the efficacy of MLT versus SLT at one-month and six-month follow-ups was present, with SLT reducing IOP by 0.83 mmHg (95% CI: 0.20, 1.47; P = 0.01) more and 0.55 mmHg (95% CI: 0.02, 1.08; P = 0.04) more than MLT, respectively. At the one-year follow-up, there was no significant disparity in IOP reduction between SLT and MLT (WMD = 0.16; 95% CI: -0.40, 0.71; P = 0.58). There was a significantly lower rate of IOP spikes in the MLT treatment group (RR = 0.37; 95% CI: 0.16, 0.89; P = 0.03). There was no statistically significant difference in the rate of treatment failures (RR = 1.05; 95% CI: 0.68, 1.62; P = 0.84) or number of topical medications reduced (WMD = 0.06; 95% CI: -0.13, 0.26; P = 0.53).

Conclusion

While SLT may offer greater short-term reductions in IOP, it may be associated with more postoperative IOP spikes when compared to MLT. At one-year follow-up, there were no significant differences in IOP reduction or failure rates between the MLT and SLT groups.

Micropulse Laser Trabeculoplasty with 577 nm Wavelength at 1500 or 1000 mW for Primary Open-Angle Glaucoma: A Pilot Study

Aim: To investigate the efficacy and safety of micropulse laser trabeculoplasty (MLT) using a 577 nm yellow wavelength laser randomly assigned to either 1500 or 1000 mW in patients with primary open-angle glaucoma (POAG). Methods: A prospective, double-blinded study of POAG patients was performed in a single center. MLT treatment included a 577 nm micropulse laser (IRIDEX IQ 577^TM, IRIDEX, Mountain View, CA, USA) to 360° of the trabecular meshwork at randomly assigned varying powers: 1500 mW in one eye (MLT 1500 group) and 1000 mW in the other (MLT 1000 group). Best-corrected visual acuity (BCVA), intraocular pressure (IOP), corneal central thickness (CCT), and endothelial cell count (ECC) were evaluated at baseline (T0), post-operative 1 h (T1), 24 h (T2), 1 month (T3), 3 months (T4), and 6 months (T5) after laser treatment. Topical medications were assessed pre-treatment and at T4. Results: Among the 18 eyes included, we achieved a success rate (IOP reduced > 20%) in 77% of sampled eyes. In particular, IOP reduced at T2 and T3 with both MLT 1500 and 1000 without any significant differences (IOP reduction 22.9% vs. 17.3%, respectively, MLT1500 vs. MLT1000 at T2). The IOP returned to baseline values at T4 and T5 in both groups, with a reduction in topical medications administered from 2.5 ± 1.1 to 2.0 ± 1.2 to the 1500 mW group and from 2.4 ± 1.0 to 1.9 ± 1.0 to the 1000 mW group. At 1 h post-laser treatment, a transient IOP spike was registered among the MLT1500 group. There were no differences in CCT and ECC at any timepoint according to the laser powers. Conclusions: Over a 6-month follow-up period, 577 nm MLT at either 1500 or 1000 mW reduces IOP, enabling a stable reduction in the number of topical medications required for patients treated for POAG without any significant difference in terms of effectiveness and safety.

A Review of Selective Laser Trabeculoplasty: “The Hype Is Real”

Presently, there is no efficacious treatment for glaucomatous optic neuropathy; the current treatment is focused on lowering intraocular pressure (IOP). Studies have demonstrated the safety and efficacy of selective laser trabeculoplasty (SLT) in reducing the IOP in eyes with open-angle (OAG) glaucoma or ocular hypertension (OH). Moreover, the European Glaucoma Society has instated SLT as the first-line or adjunctive treatment in OAG or OH, reiterating its clinical significance. In this review, we outline the old and the new roles of SLT, with an emphasis on clinical practice, and look further into its renewed appeal and future developments.