title: White light-emitting diodes (LEDs) at domestic lighting levels and retinal injury in a rat model.
abstract: BACKGROUND
  Light-emitting diodes (LEDs) deliver higher levels of blue light to the retina than do conventional domestic light sources. Chronic exposure to high-intensity light (2,000-10,000 lux) has previously been found to result in light-induced retinal injury, but chronic exposure to relatively low-intensity (750 lux) light has not been previously assessed with LEDs in a rodent model.
  
  
  OBJECTIVE
  We examined LED-induced retinal neuronal cell damage in the Sprague-Dawley rat using functional, histological, and biochemical measurements.
  
  
  METHODS
  We used blue LEDs (460 nm) and full-spectrum white LEDs, coupled with matching compact fluorescent lights, for exposures. Pathological examinations included electroretinogram, hematoxylin and eosin (H&E) staining, immunohistochemistry (IHC), and transmission electron microscopy (TEM). We also measured free radical production in the retina to determine the oxidative stress level.
  
  
  RESULTS
  H&E staining and TEM revealed apoptosis and necrosis of photoreceptors, which indicated blue-light induced photochemical injury of the retina. Free radical production in the retina was increased in LED-exposed groups. IHC staining demonstrated that oxidative stress was associated with retinal injury. Although we found serious retinal light injury in LED groups, the compact fluorescent lamp (CFL) groups showed moderate to mild injury.
  
  
  CONCLUSIONS
  Our results raise questions about adverse effects on the retina from chronic exposure to LED light compared with other light sources that have less blue light. Thus, we suggest a precautionary approach with regard to the use of blue-rich "white" LEDs for general lighting.
  
  
  BACKGROUND
  Shang YM, Wang GS, Sliney D, Yang CH, Lee LL. 2014. White light-emitting diodes (LEDs) at domestic lighting levels and retinal injury in a rat model. Environ Health Perspect 122:269-276; http://dx.doi.org/10.1289/ehp.1307294.
authors.affiliation: Institute of Environmental Health, National Taiwan University, Taipei, Taiwan.
authors.forename: Yu-Man
authors.initials: YM
authors.lastname: Shang
authors.forename: Gen-Shuh
authors.initials: GS
authors.lastname: Wang
authors.forename: David
authors.initials: D
authors.lastname: Sliney
authors.forename: Chang-Hao
authors.initials: CH
authors.lastname: Yang
authors.forename: Li-Ling
authors.initials: LL
authors.lastname: Lee
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000528:radiation effects; D003116:Color; D004596:Electroretinography; D007150:Immunohistochemistry; D008027:Light / Q000009:adverse effects*; D008297:Male; D046529:Microscopy, Electron, Transmission; D009336:Necrosis; D018384:Oxidative Stress / Q000528:radiation effects; D020419:Photoreceptor Cells, Vertebrate / Q000473:pathology / Q000528:radiation effects / Q000648:ultrastructure; D051381:Rats; D017207:Rats, Sprague-Dawley; D012160:Retina / Q000293:injuries / Q000473:pathology* / Q000528:radiation effects* / Q000648:ultrastructure; D055351:Retinal Neurons / Q000473:pathology / Q000528:radiation effects / Q000648:ultrastructure