LED-Induced Microglial Activation and Rise in Caspase3 Suggest a Reorganization in the Retina

Vision is our primary sense as the human eye is the gateway for more than 65% of information reaching the human brain. Today's increased exposure to different wavelengths and intensities of light from light emitting diode (LED) sources could induce retinal degeneration and accompanying neuronal cell death. Damage induced by chronic phototoxic reactions occurring in the retina accumulates over years and it has been suggested as being responsible for the etiology of many debilitating ocular conditions. In this work, we examined how LED stimulation affects vision by monitoring changes in the expression of death and survival factors as well as microglial activation in LED-induced damage (LID) of the retinal tissue. We found an LED-exposure-induced increase in the mRNA levels of major apoptosis-related markers BAX, Bcl-2, and Caspase-3 and accompanying widespread microglial and Caspase-3 activation. Everyday LED light exposure was accounted for in all the described changes in the retinal tissue of mice in this study, indicating that overuse of non-filtered direct LED light can have detrimental effects on the human retina as well.