Direct SLT a feasible first-line treatment for glaucoma, ocular hypertension

A direct selective laser trabeculoplasty (DSLT) falls short of achieving noninferiority to conventional selective laser trabeculoplasty (SLT) in a recent study. However, it is well tolerated and effective in reducing intraocular pressure (IOP) for up to 12 months.

“Failure to demonstrate noninferiority does not prove inferiority,” the investigators said. “DSLT remains an effective option in the early treatment paradigm and can be considered as a first-line treatment when SLT is not readily accessible.”

Participants aged ≥40 years with open-angle glaucoma or ocular hypertension, on 0‒3 hypotensive medications at screening, and washout IOP of 22‒35 mm Hg at 14 centres were enrolled in this noninferiority trial.

After washout, the investigators randomized 192 participants to DSLT (n=99) or SLT (n=93). They assessed IOP before treatment and through 12 months after the procedure, with washout IOP at baseline and 6 months. The difference in mean IOP change from baseline to 6 months (noninferiority marge, ‒1.95 mm Hg) was also assessed, as were exploratory efficacy and safety outcomes over 12 months.

Of the participants, 156 (81.3 percent) had no major protocol deviations at 6 months. The mean standard error (SE) washout IOP reduction from baseline was 5.5 mm Hg (‒20.6 percent) after DSLT and 6.2 mm Hg (‒23.6 percent) after SLT. The between-group difference was ‒0.7 mm Hg (95 percent confidence interval [CI], ‒2.2 to 0.8; p=0.09). [Ophthalmology 2025;132:1091-1104]

Among 161 participants (83.9 percent) without major protocol deviations analysed at 12 months, the mean nonwashout IOP reduction from screening was 3.2 mm Hg (‒12.2 percent) after DSLT and 3.2 mm Hg (‒9.4 percent) after SLT. The between-group difference in mean IOP reduction was 0.01 mm Hg (95 percent CI, ‒1.1 to 1.1; p<0.001).

DSLT had a safety profile similar to SLT but showed more frequent clinically nonsignificant punctate subconjunctival haemorrhage. Ocular adverse events were mild and resolved on their own.

“Delivered via an automated, noncontact, and well-tolerated treatment method, DSLT may provide a convenient and widely accessible alternative to conventional SLT across a broad range of clinical settings,” the investigators said.

Glaucoma prevalence

The global number of people with glaucoma in 2020 was estimated to be 76 million, with nearly 4 million experiencing moderate to severe visual impairment or blindness. [Ophthalmology 2014;121:2081-2090; Lancet Glob Health 2021;9:e144-e160]

Early IOP reduction is associated with sustained IOP control and less frequent glaucoma progression relative to delayed treatment over 6 years of follow-up. [Arch Ophthalmol 2002;120:1268-1279]

“Therefore, access to early effective treatment is a paramount public health concern. However, nonadherence has been shown to limit the long-term effectiveness of topical hypotensive medication, whereas widespread use of SLT is limited by lack of access to the procedure,” the investigators said. [Ophthalmology 2020;127:477-483]

“Given the high global prevalence of glaucoma and the increased recognition of SLT as the initial treatment for the disease, DSLT’s efficiency and comparable efficacy warrants first-line consideration in glaucoma’s worldwide treatment armamentarium,” they added.