Abstract
Purpose :
To investigate blue light retinopathy in the cell and mouse models.
Methods :
Cultured human retinal pigment epithelial (ARPE-19) cells and mouse cone photoreceptor (661W) cells were exposed to blue-light LED (50, 100, 250, 500, or 1000 lux) or none for 4 hours. BALB/c mice were exposed to blue-light LED 500 lux for 6 hours/day for 20 days. Cell and mouse retinal damage were assessed by various assays.
Results :
On trypan blue in situ staining, ARPE-19 cells and 661W cells were damaged since 100 lux. On CellTiter-Blue cell viability assay, cell viabilities were reduced at a dose-dependent manner since 50 lux. On TUNEL staining, apoptosis were seen at 1000 lux for 4 hours. On annexin V-propidium iodide flow cytometry, apoptosis and necrosis showed a dose relationship. On MTT assay, proportions of functional cells were reduced at a dose-dependent manner since 50 lux. On rhodamine 123 efflux assay, mitochondrial transmembrane potentials were decreased since 50 lux. On H2DCF assay measuring free radicals, reactive oxygen species (ROS) were induced at a dose-dependent manner since 250 lux. On H&E staining of the mouse retina exposed to blue light, the photoreceptors were remarkably shortened. In addition, outer plexiform layer, inner plexiform layer and ganglion cell layer also became slightly thinner. On TUNEL/DAPI staining, many of the photoreceptors showed apoptosis.
Conclusions :
Blue light damages cultured human RPE cells and mouse cone photoreceptors at a dose-dependent manner through apoptosis and necrosis. The thresholds of injury between both cells were similar. Mitochondria and oxidative stress are involved. In the mouse model, blue light induces retinal necrosis and apoptosis, particularly in photoreceptors.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.