A systematic review conducted by the American Academy of Ophthalmology (AAO) sought to analyze current literature on the efficacy of selective-laser trabeculoplasty (SLT) for the treatment of glaucoma.
Let’s start with some background.
First on the list of things to know is that this systematic review—called an Ophthalmic Technology Assessment—is a follow-up to a previous report from 2011 (published in Ophthalmology) that sought to provide an evidence-based summary on the clinical outcomes, repeatability, and safety of SLT for open-angle glaucoma (OAG).
And what were the findings then?
After a review of peer-reviewed literature, the AAO determined that SLT was a successful treatment for lowering intraocular pressure (IOP) in OAG patients.
However, the Academy noted that there was no literature available at the time that established the superiority of any form of laser trabeculoplasty; they recommended further research into the use of such lasers.
Which leads us to this new report.
Exactly.
In this 2023 report (also published in Ophthalmology), researchers conducted a thorough literature search within the PubMed databases of four months:
- March 2020
- September 2021
- August 2022
- March 2023
Out of 110 articles that were yielded—and 47 reviewed in full text—30 articles met the inclusion criteria for the report and were assigned evidence level ratings:
- Level I (19 studies)
- Well-designed and well-conducted randomized-controlled trial (RCT)
- Level II (11 studies)
- Poor-quality randomized studies and well-designed case-controlled and cohort studies
And what was the inclusion criteria?
- Study represented original research
- Study was a randomized controlled trial (RCT) studying the effects of SLT
- Study reported on glaucoma patients with glaucoma or ocular hypertension (OHT)
- Study primarily was a “results” article
Talk about these studies.
Included among the 30 articles were comparisons of SLT to glaucoma medications and non-medication treatment methods as well as assessing the effects of perioperative corticosteroids and nonsteroidal anti-inflammatory drugs (NSAIDs) on SLT treatment efficacy.
Any notable call-outs?
The report noted the Laser in Glaucoma and Ocular Hypertension (LiGHT) trial (NCT03395535), published in 2019, as one of two longer-duration studies (with 72 months of follow-up).
The LiGHT trial assessed the use of SLT as a primary treatment in patients with POAG or OHT; 72% of patients maintained IOP control at 3 years.
More recently, a 72-month extension study (ISRCTN32038223) published in May 2023 revealed that 69.8% of patients receiving SLT remained free of eye drops (with three SLT treatments approved during the study period).
Click here for the details.
So …. What were the report’s findings?
Data from the Level I evidence found SLT to be an effective treatment with minimal safety concerns for IOP control among patients with the following conditions:
- OHT
- POAG
- Pigmentary glaucoma
- Pseudoexfoliation glaucoma
- Juvenile OAG
Additionally, the data demonstrated that “SLT is equivalent to glaucoma medications for IOP control as a first-line treatment for POAG and [OHT], it may be more cost-effective than medications, and it may provide better long-term disease control than medications,” the authors wrote.
And compared to other forms of laser trabeculoplasty?
Per the authors, several Level I studies found that SLT and argon laser trabeculoplasty (ALT)—an alternative form of laser trabeculoplasty introduced prior to SLT—have equivalent IOP-lowering effects in younger patients and those with:
- OAG
- Pseudoexfoliation
- Pseudophakia
Further, repeat SLT may have longer efficacy than repeat ALT in patients initially treated with SLT.
How about IOP-lowering?
Based on the Level I studies data, SLT’s IOP-lowering effects are equivalent to:
- Titanium-sapphire laser trabeculoplasty
- Micropulse laser trabeculoplasty
- Pattern-scanning laser trabeculoplasty
And a Level II study indicated an equivalence between SLT and excimer laser trabeculotomy.
To note, post-op corticosteroid or NSAID drops following SLT had no impact on this IOP-lowering effect.
Anything else that may require further research?
Yes, actually… the authors identified a need for future research with more RCTs, diverse patient populations, and more randomized studies focused on repeatability and treatment settings.
Conclusions?
Overall, the study authors concluded that SLT can be considered an effective long-term treatment option for treating OAG, “as either a primary intervention, replacement for medication, or an additional therapy with glaucoma medications.”