Abstract
Purpose :
Given the worldwide prevalence of eye diseases with more than 2 billion people affected, there is an urgent need to understand the development and progression of these diseases and to develop effective preventive and therapeutic approaches. A link between increased exposure to blue light (BL) and various eye conditions, including myopia, cataracts, dry eye and age-related macular degeneration (AMD), is hypothesized. The common cause of these retinal neurodegenerations is increased oxidative stress. This study is based on the hypothesis that long-wave red light (RL) can protect retinal cells and reduce oxidative stress induced by BL. Photobiomodulation via RL has a great potential to be used preventively, as well as a non-invasive therapy for already existing retinal diseases. To verify this option and investigate the underlying pathways, ex vivo porcine retinas were treated with RL (660nm) on a previously established BL-damage-model.
Methods :
In the BL- degeneration model, porcine retinal organ cultures were exposed to BL, RL and a combination of both (preconditioning and post-treatment. Oxidative stress, caspase 3/7 activity and cell viability were measured. BL-induced degeneration and neuroprotection by RL were evaluated by OCT, immunohistology, Western blot and qRT-PCR. Cell-specific markers (e.g., Opsin, GFAP, β-III-tubulin, PKCα, apoptosis and stress markers (e.g., HSP70, TNFα, NfκB, Bax/Bcl-2) were analysed.
Results :
BL resulted in significant cell death, increased caspase 3/7-activity and reduced cell viability. The expression of markers for Müller cell (MC) activation and apoptosis was increased. In addition, pronounced oxidative stress was observed. In contrast, RL alone had no negative effects. Applied before or after BL exposure, RL demonstrated a reduction of oxidative stress, caspase 3/7 activity, apoptotic marker expression and MC activation. Furthermore, RL-therapy was able to protect several cell types like photoreceptors, retinal ganglion and bipolar cells from damage, even to the same level as the untreated controls. and to back to a normal level.
Conclusions :
RL could serve as a promising therapeutic option by reducing oxidative stress and preventing cell degeneration as observed in porcine retinal organ cultures. These findings suggest that RL should be further investigated as a potential therapy for various ocular conditions
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.