Red Light Therapy for Diabetic Macular Edema (DME): Scientific Evidence

Among 19 patients with early-stage diabetic macular edema (DME), a 2023 observational study reviewed real-world results of multiwavelength photobiomodulation (PBM). The group covered 30 treated eyes and was mostly male, with an average age of 56, and received 590, 660, and 850 nm light at 0.6, 4, and 65 mW/cm² in 5-minute sessions about 9 times per week for 21 to 28 days, with eye scans continuing up to 16 months. Scans pointed to a thinner central retina and clearing of fluid within it in some patients, and signs of diabetes-related damage to the retina lessened. Sharpness of vision stayed stable over 3 months, and about 64% of patients reported that their eye condition interfered less with daily life. A detailed review of the eye scans found no signs of light-related damage up to 16 months.

2022 brought an observational study following a 60-year-old man whose diabetic macular edema (DME) was treated with 670 nm photobiomodulation (PBM) on its own. His affected eye received light at 5 J/cm² from about 1.18 inches away, in sessions of 88 seconds and 4 minutes given 1 to 3 times per week across 480 days. The report found that his vision improved and the swelling in the eye resolved, with both staying stable through 16 months of follow-up. No adverse events were reported during treatment or follow-up.

4 patients with type 2 diabetes and diabetic macular edema (DME) that had not yet reached the center of the retina took part in a 2014 observational study testing 670 nm photobiomodulation (PBM). Each person had one eye treated for 80 seconds twice a day, 14 sessions per week, at 25 J/cm² and held about 1 inch from the eye, over 60 to 270 days, while the untreated fellow eye served as the comparison. All 4 treated eyes showed reduced thickening in the affected part of the retina, a change that appeared only in the eyes that received the light. No adverse effects from the therapy were reported by patients or investigators during the study.