Filtering blue light mitigates the deleterious effects induced by the oxidative stress in human retinal pigment epithelial cells

Abstract

Age-related macular degeneration (AMD) is a major cause of blindness in elderly. It is characterized by the loss of central vision due to damaged retinal pigment epithelial (RPE) cells and photoreceptors. Blue Light (BL) exposure was proposed as a risk factor for AMD progression. We undertook this study to determine the effects of BL on the behaviour of RPE cells and their potential mitigation by BL-filtering intraocular lenses (IOL). Human RPE cells were exposed or not to BL, with the absence or presence of either a clear ultraviolet (UV)-filtering IOL (CIOL), or a yellow UV- and BL-filtering IOL (YIOL). Cells were analyzed for their oxidative stress by measuring the levels of reactive oxygen species (ROS), and their viability. BL exposure significantly increased the levels of both total cellular and mitochondrial ROS. While this increase was not affected by placing the CIOL in the BL beam, YIOL decreased the levels of both ROS reservoirs. Increased ROS production was accompanied by increased cell death which was similarly decreased when cells were protected with the YIOL. Pre-treatment of cells with N-acetylcycteine (NAC) abolished the increased cell death, suggesting that the effects of BL on cell viability were mainly due to increased levels of ROS. BL is deleterious to RPE cells due to increased oxidative stress and cell death. These effects were mitigated by filtering these radiations. The use of BL-filtering devices may represent a strategy to reduce these effects on RPE cells and delay the onset of AMD.

Keywords: Blue light; Intraocular lens; Oxidative stress; Retinal pigment epithelial cells.