Effect of Subthreshold Nanosecond Laser on Loss of OCT Outer Retinal Bands in Age-Related Macular Degeneration: A LEAD Study Report.

PURPOSE

To evaluate the effect of subthreshold nanosecond laser (SNL) treatment on the rate of loss of the OCT outer retinal bands in intermediate age-related macular degeneration (AMD).

DESIGN

Post hoc analysis of the Laser Intervention in the Early Stages of AMD (LEAD) study.

PARTICIPANTS

A subset of 285 of 292 individuals in the LEAD study with bilateral large drusen without signs of multimodal imaging-defined late AMD at baseline, seen at 1 follow-up visit where neovascular AMD (nAMD) was absent.

METHODS

Participants were randomized to receive SNL or sham treatment in 1 study eye at 6-monthly intervals and were reviewed for up to 36 months. OCT scans from all visits without nAMD were automatically segmented to examine between-group differences in the rate of change in external limiting membrane (ELM), ellipsoid zone (EZ), and retinal pigment epithelium (RPE) loss in the entire central 5-mm diameter region, or only nondrusen areas in this region.

MAIN OUTCOME MEASURES

Between-group differences in the rate of ELM, EZ, and RPE loss.

RESULTS

Overall, there was no significant between-group difference in the rate of change in the loss of all OCT outer retinal band parameters ( ≥ 0.206). However, there was evidence of significant treatment effect modification based on the coexistence of reticular pseudodrusen (RPD) in the study eye when evaluating the rate of RPE loss in the entire central 5-mm diameter region, and for the rate of ELM, EZ, and RPE loss when considering only nondrusen areas in this region ( ≤ 0.006). In eyes without coexistent RPD, there was a significant slowing of the loss of all OCT outer retinal band parameters with SNL treatment ( ≤ 0.038 for all), whereas there was no significant between-group difference in all parameters in eyes with coexistent RPD ( ≥ 0.153 for all).

CONCLUSIONS

Subthreshold nanosecond laser treatment slowed the progressive loss of the OCT outer retinal bands in intermediate AMD in eyes without coexistent RPD. This study also showed for the first time the responsiveness of these novel outcome measures to treatment.

FINANCIAL DISCLOSURE

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.