Aging retinal function is improved by near infrared light (670 nm) that is associated with corrected mitochondrial decline

Abstract

Aging is associated with cellular decline and reduced function, partly mediated by mitochondrial compromise. However, aged mitochondrial function is corrected with near infrared light (670 nm) that improves their membrane potentials and adenosine triphosphate production and also reduces age-related inflammation. We ask if 670 nm light can also improve declining retinal function. Electroretinograms were measured in 2-, 7-, and 12-month old C57BL/6 mice. Significant age-related declines were measured in the photoreceptor generated a-wave and the postreceptoral b-wave. Seven- and 12-month-old mice were exposed to 670 nm for 15 minutes daily over 1 month. These showed significant improved retinal function in both waves of approximately 25% but did not reach levels found in 2-month-old animals. Our data suggest, 670 nm light can significantly improve aged retinal function, perhaps by providing additional adenosine triphosphate production for photoreceptor ion pumps or reduced aged inflammation. This may have implications for the treatment of retinal aging and age-related retinal disease, such as macular degeneration.

Photobiomodulation Mediates Neuroprotection against Blue Light Induced Retinal Photoreceptor Degeneration

“…Most studies regarding PBM postulate that the mechanism of 670 nm RL irradiation rests on photon absorption by mitochondrial complex IV, leading to enhanced ATP production and mitochondrial function in general [21,24,25,28]. Our results confirm that 670 nm RL, but also the less analyzed 810 nm NIRL photo-stimulates mitochondrial activity.…”

“…In comparison to former studies on RL/NIRL, our results demonstrate the participation of additional complexes I and II besides the proposed photoacceptor CCO [12,21,24,25,28,44]. Our results indicate that CCO may not be the main target of PBM action, leading to reduced oxidative stress.…”

“…Most of these retina-related studies concentrate especially on the beneficial effects of 670 nm red light on retinal function, while other wavelengths are only rarely studied [4,27]. Results support the hypothesis of CCO as the primary target of the mitochondrial respiratory chain leading to enhanced retinal ATP production in AMD models [21,24,25,28] and increased mitochondrial membrane potential, shown in murine RPE [26].…”

“…Several studies showed that stress markers and inflammatory markers in diseased retinas can be reduced by 670 nm red light exposure in the outer retina. RL is selectively absorbed by CCO of mitochondria; however, the exact mechanism or impact on transcription factors and gene expression is largely unknown [21,24,25,28]. While authors postulate CCO to be the main target of RL action leading to improved mitochondrial function and thus reduced cell death, there is still limited information about the impact of RL/NIRL on other respiratory complexes or mitochondria-induced apoptosis in retinal diseases.…”

“…Protective functions were reported for different neuronal and nonneuronal retinal cell types, i.e., photoreceptors, the retinal pigment epithelium (RPE), retinal ganglion cells and Müller cells [4,[13][14][15][16][17][18][19][20]. Besides studying individual cell types, several studies focus on effects in different diseases models such as age-related macular degeneration (AMD) and retinopathy models for possible transfer into therapy [18,[21][22][23][24][25][26]. Most of these retina-related studies concentrate especially on the beneficial effects of 670 nm red light on retinal function, while other wavelengths are only rarely studied [4,27].…”