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

Abstract

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.

Keywords: SLT; glaucoma; micropulse; selective laser trabeculoplasty; trabeculoplasty.

Figure 1

PRISMA flowchart for this meta-analysis.

Figure 2

This forest plot displays the meta-analysis comparing the mean reduction in intraocular pressure (IOP) between micropulse laser trabeculoplasty (MLT) and selective laser trabeculoplasty (SLT) at three different time points: (a) 1 month, (b) 6 months, and (c) 1 year. Each study is represented by the first author’s last name along with the mean difference (MD) and the 95% confidence interval (CI). The overall mean difference and 95% CI, calculated using random-effect estimations, are also depicted. The green squares indicate the effect sizes of the individual studies with their 95% confidence intervals, while the diamonds represent the pooled effect sizes with their 95% confidence intervals.

Figure 3

This forest plot illustrates the meta-analysis of the risk ratio (RR) comparing the incidence of IOP spikes (defined as an increase of more than 5 mmHg following laser treatment) between micropulse laser trabeculoplasty and selective laser trabeculoplasty. Each study is identified by the first author’s last name and shows the odds ratio (OR) with the 95% confidence interval (CI). The combined effect and 95% CI, derived from random-effect estimations, are also shown. The blue squares reflect the effect sizes of individual studies with their 95% confidence intervals, and the diamonds represent the pooled effect sizes with their 95% confidence intervals.

Figure 4

This forest plot presents the meta-analysis of the risk ratio (RR) comparing failure rates between micropulse laser trabeculoplasty and selective laser trabeculoplasty. Failure is defined as a less than 20% or less than 3 mmHg reduction in IOP, or the need for additional medications or procedures to control IOP. Each study is shown with the first author’s last name and the odds ratio (OR) with 95% confidence interval (CI). The combined effect and 95% CI, calculated using random-effect estimations, are also presented. The blue squares represent the effect sizes of individual studies with their 95% confidence intervals, and the diamonds depict the pooled effect sizes with their 95% confidence intervals.

Figure 5

This forest plot shows the meta-analysis comparing the mean reduction in the use of topical medications between micropulse laser trabeculoplasty and selective laser trabeculoplasty. Each study is identified by the first author’s last name along with the mean difference (MD) and 95% confidence interval (CI). The overall mean difference and 95% CI, derived from random-effect estimations, are also displayed. The green squares indicate the effect sizes of the individual studies with their 95% confidence intervals, while the diamonds represent the pooled effect sizes with their 95% confidence intervals.