Effects of Light‐emitting Diode Radiations on Human Retinal Pigment Epithelial Cells In Vitro

Abstract Human visual system is exposed to high levels of natural and artificial lights of different spectra and intensities along lifetime. Light‐emitting diodes ( LED s) are the basic lighting components in screens of PC s, phones and TV sets; hence it is so important to know the implications of LED radiations on the human visual system. The aim of this study was to investigate the effect of LED s radiations on human retinal pigment epithelial cells ( HRPE piC). They were exposed to three light–darkness (12 h/12 h) cycles, using blue‐468 nm, green‐525 nm, red‐616 nm and white light. Cellular viability of HRPE piC was evaluated by labeling all nuclei with DAPI ; Production of reactive oxygen species ( ROS ) was determined by H2 DCFDA staining; mitochondrial membrane potential was quantified by TMRM staining; DNA damage was determined by H2 AX histone activation, and apoptosis was evaluated by caspases‐3,‐7 activation. It is shown that LED radiations decrease 75–99% cellular viability, and increase 66–89% cellular apoptosis. They also increase ROS production and DNA damage. Fluorescence intensity of apoptosis was 3.7% in nonirradiated cells and 88.8%, 86.1%, 83.9% and 65.5% in cells exposed to white, blue, green or red light, respectively. This study indicates three light–darkness (12 h/12 h) cycles of exposure to LED lighting affect in vitro HRPE piC.