Safety Profile of Slit-Lamp-Delivered Retinal Laser Photobiomodulation
Ao, Jack Chidlow, Glyn Wood, John P.M. Casson, Robert J.
Read more:
DOI/PMID/Link: 10.1167/tvst.9.4.22
Abstract
Purpose: Photobiomodulation (PBM) refers to therapeutic irradiation of tissue with low-energy, 630- to 1000-nm wavelength light. An increasing body of evidence supports a beneficial effect of PBM in retinal disorders. To date, most studies have utilized light-emitting diode irradiation sources. Slit-lamp-mounted retinal lasers produce a coherent beam that can be delivered with precisely defined dosages and predetermined target area; however, the use of retinal lasers raises safety concerns that warrant investigation prior to clinical application. In this study, we determined safe dosages of laser-delivered PBM to the retina. Methods: A custom-designed, slit-lamp-delivered, 670-nm, red/near-infrared laser was used to administer a range of irradiances to healthy pigmented and non-pigmented rat retinas. The effects of PBM on various functional and structural parameters of the retina were evaluated utilizing a combination of electroretinography, Spectral Domain Optical Coherence (SD-OCT), fluorescein angiography, histology and immunohistochemistry. Results: In non-pigmented rats, no adverse events were identified at any irradiances up to 500 mW/cm2. In pigmented rats, no adverse events were identified at irradiances of 25 or 100 mW/cm2; however, approximately one-third of rats that received 500 mW/cm2 displayed very localized photoreceptor damage in the peripapillary region, typically adjacent to the optic nerve head. Conclusions: A safety threshold exists for laser-delivered PBM in pigmented retinas and was identified as 500 mW/cm2 irradiance; therefore, caution should be exercised in the dosage of laser-delivered PBM administered to pigmented retinas. Translational relevance: This study provides important data necessary for clinical translation of laser-delivered PBM for retinal diseases.
Year Published | 2020 |
---|---|
Country | Australia |
Rank | Positive |
Journal | Translational Vision Science & Technology |
Primary Topic | Eye |
Secondary Topic | Surgery/Transplantation |
Tertiary Topic | Photobiomodulation Therapy |
Model | Rat |
Wavelength (nm) | |
Complement/Comparison |