Light pollution: The possible consequences of excessive illumination on retina

Light is the visible part of the electromagnetic radiation within a range of 380-780 nm; (400-700 on primates retina). In vertebrates, the retina is adapted to capturing light photons and transmitting this information to other structures in the central nervous system. In mammals, light acts directly on the retina to fulfill two important roles: (1) the visual function through rod and cone photoreceptor cells and (2) non-image forming tasks, such as the synchronization of circadian rhythms to a 24 h solar cycle, pineal melatonin suppression and pupil light reflexes. However, the excess of illumination may cause retinal degeneration or accelerate genetic retinal diseases. In the last century human society has increased its exposure to artificial illumination, producing changes in the Light/Dark cycle, as well as in light wavelengths and intensities. Although, the consequences of unnatural illumination or light pollution have been underestimated by modern society in its way of life, light pollution may have a strong impact on people's health. The effects of artificial light sources could have direct consequences on retinal health. Constant exposure to different wavelengths and intensities of light promoted by light pollution may produce retinal degeneration as a consequence of photoreceptor or retinal pigment epithelium cells death. In this review we summarize the different mechanisms of retinal damage related to the light exposure, which generates light pollution.Fil: Contin, Maria Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Benedetto, María Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Quinteros Quintana, María Luz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Guido, Mario Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; Argentin

Visual opsins: Physiological alteration promoted by led light

Rods are the most sensitive cells to light present in the retina, being therefore responsible for dim light vision. Light photons captured by the retina stimulate rhodopsin, promoting phototransduction mechanisms that end up sending the information to the brain. However, overexposure to light and continuous receptor stimulation may promote retinal damage. Thus, artificial light might have harmful effects on the retina, most particularly in rods. Light‐emitting diodes (LEDs) are nowadays the most used devices, and therefore their potential damage to the visual system should be evaluated and considered as a potential environmental factor in retinal degeneration. Particularly in Wistar rats, tonic receptors stimulation under constant light exposure (LL) produces retinal remodeling, inducing classical photoreceptors death and a re-location of non-classical opsins.This work aims to show the effects of LED devices on rat retinas under intermittent stimulation. Wistar rats were exposed to white LED under 12:12 light/dark cycles for seven days (LD) to finally analyze the number of photoreceptors nuclei, electroretinograms (ERGs) activity, and glial activation. Our findings demonstrate that animals exposed to LED devices, even when they have intermittent periods of rest in darkness, present early retinal injury after seven days, compared with animals maintained in housing conditions (LDR) or darkness (DD). Altogether, these results suggest that extended LD conditions might induce retinal damage as constant light exposure (LL) does