Photobiomodulation Restores Visual Function, Has Potential Disease-modifying Effects in Dry AMD

The 24-month analysis in this study demonstrated positive clinical outcomes with improvements following PBM observed in BCVA letter gain, quality of life enhancement and anatomical outcomes such as a reduction in incident GA, suggesting a disease-modifying effect. Photo: Jessica Haynes, OD. Click image to enlarge. The recently approved procedure of photobiomodulation (PBM) for dry AMD delivers light wavelengths in the 500nm to 1000nm range to target tissues for cellular effect. The LIGHTSITE I and II studies provided foundational evidence for the benefit of multiwavelength PBM on aspects of visual function, anatomy and safety in dry AMD. More recently, the LIGHTSITE III study further investigated the effects of multiwavelength PBM treatment in dry AMD over a 24-month duration and found statistically significant improvements in BCVA immediately following the first series of PBM treatment, which were maintained through the length of the trial. The findings were reported in Retina.LIGHTSITE III employed a randomized, controlled, prospective study design. A total of 148 eyes (100 subjects) with dry eye AMD were enrolled and treated with multiwavelength PBM (Valeda Light Delivery System; 590nm, 660nm and 850nm) or sham treatment—a reduced fluence of PBM. The treatment series included nine sessions administered three times a week over three to five weeks every four months for 24 months.The study met the primary BCVA efficacy endpoint at month 21 with a significant difference between treatment groups and a +6.2 letter gain following treatment. This improvement was maintained at month 24, with a +5.6 letter gain, highlighting that PBM promotes vision recovery and also reduces progressive decline. Subgroup analyses by baseline vision demonstrated larger gains afforded to eyes with worse vision. “These findings are consistent with anti-VEGF trials showing that worse acuity at baseline predicts larger gains in vision and that patients presenting with good acuity are impacted by a ceiling effect,” the authors explained in their paper.Baseline scores for other vision tests such as contrast sensitivity, reading ability and color vision were near normal and limited the ability to detect any change following PBM treatment. The stability of these scores over 24 months supports the safety of PBM and the potential for PBM to prevent progressive decline in various aspects of visual function, the authors noted. “Vision-related quality of life demonstrated significant benefits in the PBM group and clinically meaningful deterioration in the sham group, supporting parallel quality of life benefits with PBM along with BCVA and anatomical benefits,” they wrote in their paper. For the NEI-VFQ-25, a minimal clinically important difference “is generally considered to be a four to six-point change in the composite and subscale scores. The sham group showed a significant deterioration of approximately four to 14 points in the composite score and subscales whereas the PBM group maintained QoL over the 24-month duration.”Safety data showed a strong profile with adverse events consistent with the patient population and no signs of phototoxicity. PBM treatment significantly reduced the incidence of geographic atrophy compared to sham at month 24 (6.8% vs. 24%), which is suggestive of pathological benefits, the researchers noted.“For early/intermediate dry AMD patients, BCVA improvement and/or maintained BCVA (i.e., no further decline or projected decline), and disease-modifying impact on the underlying etiology (not just late-stage growth of scar, once tissue is lost) represents clinically meaningful benefits,” the authors concluded in their paper. “Slowing progression of vision loss can change the trajectory of the disease and provide immediate improvement in quality of life, delay permanent vision loss and reduce overall healthcare costs.”Click here for the journal source. Jaffe GJ, Boyer D, Hu A, et al. Long-term efficacy and safety of photobiomodulation in dry-age related macular degeneration (LIGHTSITE III: 24-month analysis). Retina. March 3, 2026. [Epub ahead of print.] This article was developed by the editorial staff in conjunction with experts in the field. In the process, AI may have been among the editorial tools used to meet the goals of human editors, who approved all content.