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Abstract
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BACKGROUND: Light-emitting diodes (LEDs) deliver higher levels of blue light to the retina compared to conventional domestic light sources. Light-induced retinal injury due to chronic exposure to relatively low-intensity (750 lux) light in a rodent model, compared to the intensities examined in previous studies (2000-10000 lux), has not been previously assessed with LEDs.
OBJECTIVE: We examined LED-induced retinal neuronal cell damage in the Sprague-Dawley rat model through functional, histological, and biochemical measurements.
METHODS: Blue LEDs (460 nm) and full-spectrum white LEDs coupled with matching compact fluorescent lights were used for exposure treatments. Electroretinogram, hematoxylin and eosin (H&E), immunohistochemical (IHC) stain, and transmission electron microscopy (TEM) were used for pathological examinations. Free radical production in the retina was measured to determine the oxidative stress level.
RESULTS: H&E staining and the TEM study revealed apoptosis and necrosis of photoreceptors, which indicated blue-light induced photochemical injury of the retina. Free radical production in the retina increased in the LED exposure groups. The IHC stain demonstrated that oxidative stress was associated with retinal injury. While LED group demonstrated serious retinal light injury, compact fluorescent lamp (CFL) group showed moderate to mild injury from the exposure experiments.
CONCLUSION: The results raise questions related to adverse effects on the retina from chronic LED light exposure compared to current lamp sources that have less blue light. Our results suggest a precautionary approach may be advisable with regard to the employment of blue-rich "white" LEDs for general lighting.
Language: en |