LONG-TERM EFFICACY AND SAFETY OF PHOTOBIOMODULATION IN DRY AGE-RELATED MACULAR DEGENERATION (LIGHTSITE III: 24-MONTH ANALYSIS).
Level 2 - randomized trial
Double-masked, sham-controlled randomized clinical trial
PubMed 41791029 · doi:10.1097/IAE.0000000000004822
What was done
A prospective, double-masked, sham-controlled, parallel-group randomized trial (LIGHTSITE III) evaluated multiwavelength photobiomodulation (PBM using 590, 660, and 850 nm via the Valeda Light Delivery System) versus sham in 100 subjects (148 eyes) with dry age-related macular degeneration (AMD). Treatment consisted of a series of 9 sessions delivered 3 times per week over 3 to 5 weeks, repeated every 4 months across a 24-month follow-up period.
What was found
The trial met its primary best-corrected visual acuity (BCVA) efficacy endpoint at month 21, demonstrating a statistically significant difference between groups (P = 0.0036) with a +6.2 letter gain in the PBM arm. At month 21, 61.5% of PBM-treated eyes gained ≥5 letters, 23.1% gained ≥10 letters, and 4.4% gained ≥15 letters. At month 24, progression to geographic atrophy was significantly lower in the PBM group compared to sham (6.8% vs. 24.0%, P = 0.007). Vision-related quality of life showed significant benefit, and no signs of phototoxicity were reported.
Why it matters
This study provides 24-month sham-controlled trial evidence that non-invasive multiwavelength photobiomodulation can improve visual acuity and slow progression to geographic atrophy in dry AMD, an area with few restorative interventions.
Limits
The sample size is modest (100 subjects, 148 eyes). The abstract does not provide exact sham group letter changes, confidence intervals, baseline visual acuity characteristics, or numerical scores for the reported quality-of-life improvements.