Effectiveness of Selective Laser Trabeculoplasty Applied to 360° vs. 180° of the Angle

180- Versus 360-Degree Selective Laser Trabeculoplasty in Open Angle Glaucoma and Ocular Hypertension: A Systematic Review and Meta-Analysis

PRCIS

This systematic review and meta-analysis found that 360-degree selective laser trabeculoplasty (SLT) is significantly more effective than 180-degree SLT at reducing intraocular pressure at 1-month and 1-year follow-ups without increased serious adverse event risk.

PURPOSE

To determine the efficacy of 180- versus 360-degree selective laser trabeculoplasty (SLT) in adults with open angle glaucoma (OAG) and ocular hypertension (OHT).

METHODS

A systematic review was performed using PubMed, Embase, and Scopus databases, from 1995 to December 30, 2023, for studies comparing 180 and 360-degree SLT in adults with OAG and OHT (PROSPERO ID: CRD42024497832). Meta-analyses were performed to calculate nominal percent and raw reductions in intraocular pressure (IOP) between treatment groups at 1-month, 1-year, and 2-year follow-ups, as well as success rates, defined as a 20% or greater IOP reduction.

RESULTS

Nine studies with 1044 eyes were included; 491 received 180-degree SLT, and 553 received 360-degree SLT. At the 1-month follow-up, 360-degree SLT reduced IOP by 3.45% more (WMD=3.45; 95% CI: 2.02-4.88; P <0.00001) and 0.87 mm Hg more (WMD=0.87; 95% CI: 0.35-1.38; P =0.0010). At the 1-year follow-up, 360-degree SLT reduced IOP by 4.33% more (WMD=4.33; 95% CI: 2.35-6.32; P <0.0001) and 1.15 mm Hg more (WMD=1.15; 95% CI: 0.25-2.04; P =0.01). At 2 years of follow-up, 360-degree SLT reduced IOP by 4.86% more (WMD=4.86; 95% CI: -0.32, 10.0; P =0.07) and 1.25 mm Hg more (WMD=1.25; 95% CI: -0.29, 2.79; P =0.11); however, the difference was not statistically significant. Compared with 360-degree SLT, 180-degree SLT had a significantly lower success rate (OR=0.50; 95% CI: 0.35-0.72; P =0.0002). There was no difference in serious complications between interventions.

CONCLUSIONS

360-degree SLT is more effective than 180-degree SLT at lowering IOP at 1-month and 1-year follow-ups as well as achieving successful IOP control without increased risk of serious complications.

Selective laser trabeculoplasty: An updated narrative review

Selective laser trabeculoplasty (SLT) has experienced a resurgence in interest, primarily driven by promising findings from the Laser in Glaucoma and Ocular Hypertension Trial. By offering SLT as an initial drug-free treatment option, we may be able to thwart issues such as adherence and persistence that plague our current medical management protocols. In this comprehensive narrative review, we delve into the current body of literature that explores the utility of SLT across a wide spectrum of scenarios and glaucoma subtypes. We present evidence that provides valuable insight into the efficacy and benefits of SLT, positioning it as a viable option in the management of glaucoma. Careful consideration of the associated risks and challenges is also necessary for successful adoption into clinical practice. Despite the ample evidence supporting SLT's efficacy, some questions remain regarding its long-term effects and the potential need for retreatment. This review aims to shed light on these aspects to guide clinicians in making informed decisions and tailoring treatment plans to individual patient needs. This review also provides the readers with a bird's eye view of the potential impact of SLT and adds clarity to the various therapeutic protocols that one can follow to ensure optimal clinical outcomes for our patients.

Optimal Performance of Selective Laser Trabeculoplasty: Results from the Swedish Optimal SLT Multicenter Randomized Controlled Trial

PURPOSE

Selective laser trabeculoplasty (SLT) is a first-line treatment for glaucoma and ocular hypertension. However, due to insufficient comparative evidence in efficacy and safety, several SLT treatment protocols are currently used in practice. The objective of this trial was to compare the clinical outcomes of the 4 most significant SLT variants.

DESIGN

Prospective, multicenter, masked, randomized controlled trial (RCT).

PARTICIPANTS

Four hundred patients with glaucoma or ocular hypertension. The cohort consisted of both treatment-naive patients and patients undergoing glaucoma treatment, at different stages of disease.

METHODS

Selective laser trabeculoplasty was performed with 50 ± 5 laser spots in 180 degrees or with 100 ± 10 spots in 360 degrees. The laser power was titrated to either just below the cavitation bubble level ("standard energy") or to a level producing cavitation bubbles at 50% to 75% of laser applications ("high energy"). Thus, 4 different treatment protocols were included - 180/standard, 180/high, 360/standard, and 360/high. The study adhered as close as possible to regular clinical management, but within a scientific framework.

MAIN OUTCOME MEASURES

Reduction of intraocular pressure (IOP) 1 to 6 months after SLT. The proportion of patients achieving a 20% IOP reduction without any further intervention. Time to glaucoma treatment escalation in a Kaplan-Meier survival analysis.

RESULTS

SLT performed with the 360/high protocol was shown to be superior regarding all primary endpoints. The IOP reduction 1 to 6 months after SLT was 5.4 mmHg in the 360/high group, compared to 3.4, 3.2, and 4.2 mmHg with the 180/standard, 180/high, and 360/standard protocols, respectively (P < 0.001). Furthermore, the success rate after 6 months was significantly higher -58.3%, compared with 30.2%, 29.3%, and 41.7% (P < 0.001). The median time to glaucoma treatment escalation was more than twice as long with 360/high SLT -1323 days, compared to 437 days, 549 days, and 620 days (P < 0.001). Although postoperative discomfort was more frequent with the 360/high protocol, symptoms were generally mild and transient. Adverse events were rare in all groups.

CONCLUSIONS

The magnitude and longevity of SLT results increases substantially if SLT is performed according to the 360/high protocol, without compromising safety. Therefore, we recommend that 360/high SLT be considered as standard treatment.

FINANCIAL DISCLOSURES

The authors have no proprietary or commercial interest in any materials discussed in this article.

Selective Laser Trabeculoplasty

Selective laser trabeculoplasty (SLT) is a common ophthalmic procedure used to lower intraocular pressure. The mechanism of SLT action remains controversial but may involve the upregulation of protein expressions in the trabecular meshwork that increases outflow facility. Several prospective trials have demonstrated the safety and efficacy of SLT as both adjunctive and primary glaucoma therapy, and the utilization of SLT in stable, medically-controlled glaucoma patients may decrease medication burden and potentially improve the patients’ quality of life.

Five-year outcomes of selective laser trabeculoplasty: A retrospective study

Introduction

Studies have shown the efficacy of selective laser trabeculoplasty (SLT) to lower intraocular pressure (IOP) as adjuvant therapy during short-term follow-up. However, few studies have assessed the long-term efficacy of SLT on preventing worsening Humphrey visual field (HVF) parameters and thinning of the retinal nerve fiber layer (RNFL) with continued medical therapy.

Methods

A retrospective chart review was conducted of 51 eyes of 39 patients with glaucoma treated with SLT at Boston Medical Center between 2012 and 2016 with 3- and 5-year follow-up. Outcome measures included IOP, visual acuity, number of glaucoma medications, number of months to subsequent surgical intervention. HVF outcome measures included mean deviation (MD) and pattern standard deviation (PSD). Optical coherence tomography (OCT) outcome measures included RNFL mean thickness, and superior and inferior thicknesses.

Results

Twenty-five eyes received subsequent surgical intervention (mean time to intervention = 33.6 ± 20.0 months). In the eyes that did not receive another intervention, mean IOP was significantly decreased by 3.2 and 3.5 mmHg at 3- and 5-year after SLT, respectively. Mean number of glaucoma medications was significantly increased at 5-year (2.7 ± 1.6; P = 0.04), compared to pre-SLT (2.0 ± 1.1). Mean HVF MD was significantly higher at 5-year (-7.64 ± 6.57 dB) compared to pre-SLT (-5.61 ± 3.90 dB). Mean PSD significantly increased at 3-year (5.30 ± 2.91 dB) and 5-year (6.84 ± 2.62 dB), compared to pre-SLT (4.63 ± 2.70 dB; P = 0.04 and ≤0.01, respectively). On OCT, inferior quadrant RNFL thickness decreased significantly at 5-year (88.5 ± 19.3 μm), compared to pre-SLT (94.0 ± 23.2 μm).

Discussion

Although 51% of eyes had IOP controlled at 5-year post-SLT, mean number of glaucoma medications was significantly higher. Also, there was progression of MD and PSD on HVF and inferior quadrant thinning on OCT at 5-year. We found a significant association between age at SLT and risk of subsequent surgical intervention over 5-year follow-up. Our study adds to our understanding of long-term outcomes of adjuvant SLT for glaucoma patients receiving medical therapy.

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.

Selective Laser Trabeculoplasty in the Treatment of Ocular Hypertension and Open-Angle Glaucoma: Clinical Review

Selective laser trabeculoplasty (SLT) is a glaucoma treatment that reduces intraocular pressure (IOP). Its mechanism is based on the biological effects of the selective application of laser energy to pigmented trabecular meshwork (TM) cells, resulting in increased outflow facility. Herein, we review current publications on SLT and summarize its efficacy and safety for different indications in open-angle glaucoma (OAG) and ocular hypertension (OHT) treatment. SLT effectively reduces IOP when used as a primary treatment. In patients whose IOP is medically controlled, SLT helps to reduce medication use, and when maximally tolerated topical therapy is ineffective, SLT facilitates the realization of the target IOP. SLT is a repeatable procedure for which the vast majority of complications are mild and self-limiting. With effective IOP reduction, low complication rates and the potential to repeat the procedure, SLT offers the possibility of delaying the introduction of medical therapy and other more invasive treatment modalities while simultaneously avoiding the accompanying complications. With this knowledge, we suggest that SLT be considered as an essential primary treatment option in OAG and OHT, switching to other treatment modalities only when laser procedures are insufficient for achieving the required target IOP.