Researchers led by Robyn H. Guymer, MBBS, PhD, of the Department of Ophthalmology at the University of Melbourne, Australia, conducted the 292-patient Laser Intervention in Early Stages of Age-Related Macular Degeneration (LEAD) study to determine if subthreshold nanosecond laser (SNL) treatment (Ellex) could be a safe and effective intervention to slow or prevent progression of AMD from its early stages to vision-threatening late complications. According to Ellex, SNL treatment has shown promise in preclinical studies and a pilot study in intermediate AMD as a potential treatment for this unmet need.
The LEAD study is a 36-month, multicenter, randomized, sham-controlled trial whose results were recently reported in the journal Ophthalmology. In the study, participants were assigned randomly to receive retinal rejuvenation therapy (2RT; Ellex) SNL or sham treatment to the study eye at 6-month intervals. The primary efficacy outcome was the time to development of late AMD defined by multimodal imaging (MMI). Safety was assessed by adverse events.
The researchers found that, overall, progression to late AMD was not slowed significantly with SNL treatment compared with sham treatment. However, a post-hoc analysis showed evidence of effect modification based on the coexistence of reticular pseudodrusen (RPD), where progression was slowed for the 222 participants (76.0%) without coexistent RPD at baseline, whereas an increased progression rate was observed for the 70 participants (24.0%) with baseline RPD. Differences between the groups in serious adverse events were not significant.
The researchers concluded that in participants with intermediate AMD without MMI-detected signs of late AMD, no significant difference in the overall progression rate to late AMD between those receiving SNL and sham treatment were observed. However, SNL treatment may have a role in slowing progression for those without coexistent RPD and may be inappropriate in those with RPD, warranting caution when considering treatment in clinical phenotypes with RPD. The researchers said their findings provide compelling evidence for further trials of the 2RT laser, but they should not be extrapolated to other short-pulse lasers.