AIM: To investigate the effects of different wavelength of blue light on human retinal pigment epithelial(RPE)cells.

METHODS: ARPE-19 cells cultured in vitro were randomly divided into four groups, which were control group, 447nm blue light group, 456nm blue light group and 468nm blue light group. The cells in control group were cultured under normal conditions whereas the cells in blue light group were irradiated with different wavelengths of OLED blue light with the illumination intensity of 200Lux for 72h. Live/Dead staining assay, CCK-8 assay and real-time PCR were performed to compare the effects of different wavelengths of blue light on the morphology, cell viability, proliferation capacity, mRNA expression level of visual cycle biomarkers and inflammatory biomarkers of ARPE-19 cells, respectively.

RESULTS: After blue light irradiation, the abnormal morphology and the decrease of cell confluence of ARPE-19 cells were observed. Furthermore, with the decrease in the wavelength of blue light, the inhibition effect of blue light on RPE proliferation was enhanced, and the mRNA expression of the proliferation marker Ki-67 and visual cycle biomarkers LRAT, CRALBP, RDH and IRBP decreased. In addition, the mRNA expression levels of inflammatory factors MCP-1 and IL-6 in RPE cells were up-regulated with the decrease in the wavelength of blue light.

CONCLUSION: Our data demonstrated that blue light in different wavelengths exerted detrimental effects on RPE cells. The shorter the wavelength of blue light was, the more severe damage it caused on the RPE cells.