Purchase this article with an account.
Yu-Man Shang, Chang-Hao Yang, Gen-Hsuh Wang, Luke Long-Kuang Lin; LED light source induced retinal photoreceptor hazard in a rat model. Invest. Ophthalmol. Vis. Sci. 2013;54(15):4199.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
White light Light Emitting Diode (LED) wavelength is ranged from 400 nm to 550 nm which is the retinal hazard region. The sharp blue peak in the spectrum signifies the strong intensity which causes blue light hazard, but hard to be recognized by human eyes. Therefore, medical study and description is critical to clarify its mechanism and dose response relationship.
To determine the key risk factors for the retinal LED blue light hazard, parameters such as wavelength, light spectrum, intensity, exposure duration as well as color temperature were included in the animal study. While Electroretinogram (ERG) used as functional testing, histological analyses (HE stain, TUNEL stain, and TEM) approached as morphological investigation. Adult male Sprague Dawley rats were grouped and exposed to different light treatments. Single wave blue (460nm) LED, Full spectrum LED with Correlated Color Temperature (CCT) 3000 - 6500K and compact fluorescent light (CFL) were adapted; Intensity from 150-3000lux with total exposure time range from a week to 4 weeks under the light cycle of 12h-dark / 12h-light will be distributed into the parameter matrix. Each rat was dark adapted 24 hours before ERG testing and maintained individually in a 12h-light / 12h-dark light cycle with ad libitum. Furthermore, the rats were rescanned by ERG during the exposure process at 1-2 week and prolonged 2 weeks in the dark after the exposure. The rats after the post treatment ERG were sacrificed and their retinal tissues will be taken for pathological analysis.
The pathological experiments examined the apoptosis and necrosis condition on retinal photoreceptors and confirmed the blue light photochemical injury to the retina with the signs of retinal degeneration. Some important biomarkers were identified such as thinner of outer nuclear layer (ONL) and photoreceptors disappearance. The TEM also demonstrated mitochondria swollen, macrophage activity, and myeloid body on retinal pigment epithelial (RPE) indicating the photochemical injure by the blue light exposure. Moreover, ERG b-wave data evidenced this trend showing the dose dependent relationship as well.
Both functional and morphological analysis supported the retinal LED blue light hazard and confirmed the radiance characteristic is the key risk factor to this injury. However, other domains such as biochemistry analysis can be also performed for further study.
This PDF is available to Subscribers Only