Riccardo Natoli, Matt Rutar,Rizalyn Albarracin, Krisztina Valter,Jan Provis
Age-related macular degeneration (AMD)is significantly associated with inflammation andoxidative-damage in the retina, however, there arelimited treatment options to target these facets of the disease. 670 nm photobiomodulation (PBM) down mo-dulates oxidative-damage and inflammation in varioustissues. We investigated 670 nm PBM as a potentialtreatment for ‘dry’ AMD, using a rodent model.
Sprague-dawley rats were exposed to1000 lux damaging light for 24 hours. Animalswere treated with 670 nm red light (3 minutes @ 9 J/cm2) for 5 days prior to damaging-light exposure.Gene expression analyses were performed usingmicroarrays and qRT-PCR. Retinal samples were alsoinvestigated for cell death (TUNEL), complementprotein (C3) and lipid peroxidation (4-HNE) usingimmuonhistochemistry.
Following light damage, retinas pre-treatedwith 670 nm light had significantly less photoreceptordeath and reduced immunoreactivity for 4-HNE com-pared to controls. 670 nm treatment also modulatedgene expression in our model, to a similar expressionlevel of controls. There was significant reduction inretinal expression of complement genes C1s, C2, C3,C4b, C3aR1, and C5r1 following 670 nm treatment, aswell as a number of previously unknown retinalncRNA.
670 nm treatment may be effective inmanaging retinal degenerations, including AMD,where oxidative damage and inflammation are signifi-cant features.