■ A compelling Italian ARVO study (the Gandolfi Study) demonstrated that a regimen of low-energy selective laser trabeculoplasty (SLT) repeated annually irrespective of IOP produced significantly longer medication-free survival than standard SLT repeated as needed, in patients with primary open-angle glaucoma (POAG) or high-risk ocular hypertension (OHTN). Specifically, newly diagnosed POAG eyes were treated primarily either with SLT 360° performed once, standard SLT 360° repeated as needed at standard energy, and low-energy 360° SLT (0.4 mJ/spot in 50-60 spots) repeated annually at low energy regardless of IOP.

After 10 years of follow-up, medication-free rates were 22.6% in the ALT group, 25.0% in the standard SLT group, and 58.3% in the low-energy SLT group. The median times to medication were 2.8 years, 3.2 years, and 6.2 years, respectively.

These eye-opening data piqued the interest of researchers led by Tony Realini, MD, of West Virginia University, to conduct a comprehensive review of the SLT literature in search of a basis for the biological plausibility of such an approach. The results of that literature review prompted application to the NEI for funding to conduct a pair of multicenter randomized trials to evaluate outcomes of SLT performed annually at low energy. These trials — collectively named the Clarifying the Optimal Application of SLT Therapy (COAST) trial — were funded in late 2020 by the NEI to compare standard vs low-energy primary SLT and annual vs PRN repeat SLT and are currently in the pre-enrollment phase.