Short-term efficacy of photobiomodulation in early and intermediate age-related macular degeneration: the PBM4AMD study

Objectives: This independent prospective study evaluated the short-term effects and safety of photobiomodulation (PBM) in early and intermediate age-related macular degeneration. Methods: patients were treated with PBM in one eye. Functional parameters and drusen volume were measured at one (W4), three- (W12) and six-months (W24) after PBM. Results: The study included 38 subjects who completed the PBM protocol. Two patients developed macular neovascularization during the study period. Best corrected visual acuity improved from 77.82 ± 5.83 ETDRS letters at baseline to 82.44 ± 5.67 at W12 (p < 0.01), then declined to 80.05 ± 5.79 at W24 (p < 0.01 vs. baseline). Low luminance visual acuity showed a similar pattern, improving from 61.18 ± 8.58 ETDRS letters at baseline to 66.33 ± 8.55 at W12 (p < 0.01), and decreasing to 62.05 ± 9.71 at W24 (p = 0.02). Contrast sensitivity improved at W12 (20.11 ± 9.23 ETDRS letters, p < 0.01), but returned to baseline by W24 (16.45 ± 9.12, p = 0.5). Scotopic microperimetry showed a decrease in mean absolute retinal sensitivity from 9.24 ± 3.44 dB to 7.47 ± 4.41 dB at W24 (p < 0.01), while relative sensitivity decreased only at W24 (p = 0.04). Drusen volume decreased at W4 (0.018 ± 0.009 mm3, p < 0.01) and W12 (0.017 ± 0.009 mm3, p < 0.01), with a slight increase at W24 (0.019 ± 0.012 mm3, p = 0.154). Conclusions: PBM resulted in temporary improvements in visual function and a reduction in drusen volume, but these effects were not sustained at six months. The long-term efficacy and impact on disease progression are uncertain, necessitating further research to confirm these findings and determine optimal patient selection.