Abstract
INTRODUCTION: This study aimed to evaluate the safety and efficacy of multiwavelength photobiomodulation (PBM) treatment (Tx) in earlier stages of nonexudative (dry) age-related macular degeneration (AMD). METHODS: Participants were enrolled with a diagnosis of dry AMD. Participants were treated with a single or repeated series of multiwavelength PBM treatment (LumiThera Valeda(®) Light Delivery System; 590, 660, and 850 nm) delivered three times per week over 3-5 weeks every 4 months with follow-up extending out to 16 months. Outcomes analyzed included visual acuity (VA), contrast sensitivity (CS), and electroretinography (ERG). RESULTS: A total of 41 eyes (27 participants) were evaluated after single (1 series of Tx, n = 41 eyes) and repeat (2-4 series of Tx, n = 26 eyes) PBM treatment with up to 16 months of follow-up. Participants were mostly female (n = 22, 81.5%) with a mean time since AMD diagnosis of 5.6 years. Participants enrolled had earlier stage dry AMD with better vision (~ 20/32 Snellen) and a mean baseline VA of 76.5 letters. Single and repeated PBM Tx improved VA, CS, multi-luminance ERG, and fixed luminance ERG parameters. No significant visual decline was noted in any outcome measure or signs of phototoxicity. CONCLUSIONS: PBM treatment of patients with earlier stage dry AMD showed improvements on multiple visual outcome measures and no adverse effects. Earlier stage AMD populations may not show robust magnitude effects as their starting vision does not show serious deficits, however; as a result of the degenerative and progressive nature of the disease, repeat treatment and continued monitoring of these outcomes are of interest. These beneficial effects were improved with repeated PBM treatment series.