Safety, Tolerability, and Short-Term Efficacy of Low-Level Light Therapy for Dry Age-Related Macular Degeneration

Abstract

Introduction: Photobiomodulation (PBM) has become a promising approach for slowing the progression of early and intermediate dry age-related macular degeneration (dAMD) to advanced AMD. This technique uses light to penetrate tissues and activate molecules that influence biochemical reactions and cellular metabolism. This preliminary analysis is aimed at assessing the safety, tolerability, and short-term effectiveness of the EYE-LIGHT^®PBM treatment device in patients with dAMD.

Methods: The EYE-LIGHT^® device employs two wavelengths, 590 nm (yellow) and 630 nm (red), in both continuous and pulsed modes. Patients over 50 years of age with a diagnosis of dAMD in any AREDS (Age-Related Eye Disease Study) category were randomly assigned to either the treatment group or the sham group. The treatment plan consisted of an initial cycle of two sessions per week for 4 weeks. Safety, tolerability, and compliance outcomes, along with functional and anatomical outcomes, were assessed at the end of the fourth month.

Results: This preliminary analysis included data from 76 patients (152 eyes). All patients were fully compliant with treatment sessions, and only one fifth of patients treated with PBM reported mild ocular adverse events, highlighting exceptional results in terms of tolerability and adherence. Changes in best-corrected visual acuity (BCVA) from baseline to month 4 differed significantly between the sham and PBM-treated groups, favoring the latter, with a higher proportion achieving a gain of five or more letters post-treatment (8.9% vs. 20.3%, respectively; p = 0.043). No significant differences in central subfield thickness (CST) were observed between the two groups over the 4-month period. The study also found a statistically significant disparity in mean drusen volume changes from baseline to month 4 between the groups in favor of patients treated with PBM (p = 0.013).

Conclusion: These preliminary results indicate that PBM treatment using the EYE-LIGHT^® system is safe and well tolerated among patients with dAMD. Furthermore, both functional and anatomical data support the treatment's short-term efficacy.

Trial registration: ClinicalTrials.gov identifier NCT06046118.

Keywords: Age related macular degeneration; Drusen; Dry AMD; Low-level light therapy; Photobiomodulation.

Fig. 1

Representative image showing the mask and the treatment modality. A Schedule of each cycle and session when used in the setting of dry age-related macular degeneration. B Subsequent phases performed during each treatment session. Specifically: (1) 300 s of continuous yellow light delivered with eyes closed and 60 s of pulsed yellow light delivered with eyes opened; (2) 300 s of continuous red light delivered through eyes closed and 60 s of pulsed red light delivered with eyes opened. LM^® LLLT Light Modulation^® Low-level Light Therapy

Fig. 2

Brief Ocular Discomfort Inventory questionnaire

Fig. 3

A, C, E Changes from baseline (BL) to month 4 (M4) in the sham- and PBM-treated groups for best-corrected visual acuity (BCVA), mean drusen volume (MDV), and central subfield thickness (CST), respectively. P-value refers to the comparison within each group. B, D, F Comparison of changes between baseline and month 4 in the sham- and PBM-treated groups for BCVA, MDV, and CST, respectively. Δ delta of change, PBM photobiomodulation

Fig. 4

Representative OCT B-scans showing the reduction of macular drusen in a patient belonging to PBM group. A Baseline (BL). B Month 4 (M4)