Authors: Yang Daidi, Sun Ruxu, Chen Xue, Liu Qinghuai
To study the damage effects of blue-light exposure on retinal morphology and function in mouse.
Twenty 8-week-old clean C57BL/6J mice were randomly divided into blue-light exposure group and normal control group by coin tossing method.The mice in the blue-light exposure group was exposed to 10 000 lx blue light for 5 days after dark adaptation for 24 hours, and the mice in the normal control group was kept under the normal light intensity for 5 days at 12-hour light/12-hour darkness cycles.The retinal thickness was detected by optical coherence tomography (OCT), and retinal function was evaluated by electroretinogram (ERG). The mice was sacrificed and the frozen section and flat mount of eyeball wall was created at 24 hours after irradiation.The expressions of rhodopsin (Rho), zonula occludens-1 (ZO-1) and β-catenin in the retinas were detected by immunofluorescent staining.The use and care of the experimental animals adhered to ARVO Statement by American Society of Visual and Ophthalmological Sciences (No.IACUC-1803029).
The thickness of the retinal outer nuclear layer at 200, 400, 600, 800 and 1 000 μm from the superior and inferior to optic nerves were thinned in the mice of the blue-light exposure group compared with those of the normal control group, showing significant differences between the two groups (all at P<0.05). The b-wave amplitude of the scotopic and photopic ERG was (305.50±41.52)μV and (119.50±6.67)μV in the blue-light exposure group, respectively, which was significantly reduced in comparison with (415.50±28.77)μV and (139.75±8.26)μV of the normal control group (both at P<0.05). Immunofluorescent staining showed that the retinal pigment epithelial (RPE) cells of the mice exhibited hexagonal shape with regular arrangement, retinal morphology was regular, and the expressions of Rho, ZO-1 and β-catenin proteins showed stronger fluorescence in the retinas of normal control group.However, structural disorder, diminishing fluorescence intensity of Rho, ZO-1 and β-catenin were found in the blue-light exposure group.The morphology of the retina was disordered while the cell structure was destroyed.
Blue-light irradiation results in morphological and functional damages of retina.