| Research background and purpose:Myopia is the most important disease affecting the visual health of young people,which brings a lot of inconvenience to the lives of young people and children and increases the social burden.The light environment is closely related to the occurrence and development of myopia.Full spectrum and high light intensity have been proven to delay the development of myopia.At present,there are few studies on the influence and mechanism of full-spectrum lighting on myopia,and there are fewer comparisons between LED lighting with different spectra and different illuminances,and there are differences between different clocks.This study will conduct safety and efficacy studies at the cell level and animal level respectively.Explain the connection and mechanism of full-spectrum lighting and myopia prevention and control.Provide a convenient and safe new method for the prevention and control of myopia in adolescents and children.Methods:（1）Effects of full-spectrum lighting on retinal pigment epithelial cellsARPE-19 cells were selected in the experiment.LED lighting lamps with different spectrums were placed in a closed CO2incubator.Use an illuminometer to measure the illuminance on the cell culture plane,and adjust the illuminance to the target illuminance by covering the cell culture plate with uniform light films of different thicknesses.ARPE-19 cells cultured in vitro were randomly divided into 7groups:control group,non-full-spectrum lighting group（subdivided into two subgroups of 300 lux and 600 lux）,full-spectrum lighting group（subdivided into four subgroups of 100 lux,300 lux,600 lux,and 900 lux）subgroup),the cells in the control group were cultured in the dark,and the cells in the other groups were intervened with the corresponding spectrum and light intensity.After 24 hours,48 hours,and 72 hours,use an inverted fluorescence microscope to observe the morphological changes of the cells in each group,and CCK-8 to detect the cell viability after different light environment interventions;live/dead cell staining to evaluate the damage of ARPE-19cells;TMRE staining,and the mitochondrial membrane potential of the cells was detected by fluorescence microscopy.（2）Effects of full-spectrum lighting on the refractive development of guinea pigsAlbino guinea pigs at the age of 2 weeks were selected in the experiment.Fix LED lights of different spectrums directly above the special rearing frame,and fix blackout curtains around them.Use an illuminance meter to measure the light intensity at the bottom of the cage,and adjust the height of the lighting lamp from the bottom of the cage and cover the lighting fixture with a uniform light film to achieve the target illuminance.Use a timing device to ensure a lighting environment with 12 hours of light and 12 hours of darkness.Twenty 2-week-old albino guinea pigs were randomly divided into 4 groups:full-spectrum LED lighting 300 lux group,full-spectrum LED lighting 600 lux group,non-full-spectrum LED lighting 300 lux group,non-full-spectrum LED lighting 600 lux group.The guinea pigs were intervened with the corresponding spectrum and light intensity for 12 weeks.Before the experiment and every 2 weeks after the experiment,the guinea pigs in each group were measured for eye axis.Before the experiment and every 4 weeks after the experiment started,the guinea pigs were measured for diopter and the guinea pig cornea,conjunctival sac,lens and corneal fluorescence staining were observed.Lacrimal secretion tests were performed before the experiment and at the 12th week of the experiment.At the 12th week of the experiment,OCT was used to detect the thickness of the retina in living guinea pigs.The retinal tissues of guinea pigs in each group were collected,and HE staining was used to detect the morphological changes of the cornea,lens,retina,and structural changes of important organs.ELISA kits were used to detect dopamine and5-HT and retinoic acid levels.Results:（1）Under the same illumination conditions,after 72 hours,full-spectrum lighting showed higher cell viability than non-full-spectrum lighting;the number of cell death in the full-spectrum lighting group was lower;The potential relative fluorescence intensity is higher than that of the non-full-spectrum illumination 600 lux group.Under the same spectral conditions,there was no significant difference in cell viability between the non-full-spectrum lighting groups,and between the full-spectrum lighting groups:after 72 hours,the cell viability was higher in the higher illumination of 600lux and 900 lux than in the low illumination of 100 lux.After 72 hours of illumination,the relative fluorescence intensity of mitochondrial membrane potential in the full-spectrum 100 lux group was higher than that of the full-spectrum illumination 300lux.（2）Before the beginning of the experiment,there was no statistical difference in the depth of anterior chamber,the thickness of lens,the depth of vitreous cavity and the length of eye axis in each group,but the data of each group gradually increased with time.Before the beginning of the experiment,there was no significant difference in the diopter of the guinea pigs in each group.4 weeks after the beginning of the experiment,myopia appeared,and myopia shift occurred with the extension of time.Under the same illuminance,there was no significant difference in axial length between 300 lux groups.After 2-12 weeks of illumination,the axial length of the eye in the full-spectrum illumination 600 lux group was slower than that in the non-full-spectrum illumination 600 lux group.At 12 weeks,the average difference between full-spectrum illumination 600 lux group eye axis length（9.275±0.065 mm）and non-full-spectrum illumination 600 lux group eye axis length（9.576±0.086 mm）was 0.306mm.After 4-12 weeks of illumination,the degree of myopia in the full spectrum illumination group was lower than that in the non full spectrum illumination group（P<0.01）.At 12 weeks,the average difference of diopter between full-spectrum illumination 600 lux group（-1.925±0.169 D）and non-full-spectrum illumination600 lux group（-2.825±0.290 D）was 0.9 D P<0.0001.The retinal thickness in the full-spectrum illumination group was higher than that in the non-full-spectrum illumination group.The content of DA in the full-spectrum group was higher than that in the non-full-spectrum group,while the content of 5-HT in the full-spectrum group was lower than that in the incomplete-spectrum group,but the difference was not statistically significant.There was no significant difference in the content of retinal RA among the groups.Under the same spectral conditions,there was no significant difference in eye axis length between non-full-spectrum illumination groups.The axial length of the 600 lux group was lower than that of the 300 lux group from 2 to 12weeks after the experiment.At the 8th and 12th week of the experiment,the myopia of the 600 lux group was lower than that of the 300 lux group,and from the 4th to 12th week,the myopia of the 600 lux group was lower than that of the 300 lux group.The retinal thickness in the non-full spectrum group was lower than that in the lower illumination group.The content of DA in higher illumination group was higher than that in lower illumination group,while the content of 5-HT in higher illumination group was lower than that in lower illumination group,but the difference was not statistically significant.There was no significant difference in the content of retinal RA among the groups.Under the condition of comprehensive consideration of spectrum and illuminance,the changes of axial length and diopter in 600 lux group were slower than those in other groups.The retinal DA content of full-spectrum illumination 600lux group（166.555±22.464 pg/mg）was higher than that of non-full-spectrum illumination 300 lux group（108.321±19.742 pg/mg）and 5-HT content（1.436±0.069 pg/ul）was lower than that of non-full-spectrum illumination 300 lux group（1.854±0.197 pg/ul）.The difference was statistically significant.Conclusions:（1）Compared with non-full-spectrum LED illumination,full-spectrum LED illumination caused less damage to RPE cells,and no obvious damage to cornea,lens,retina and organs of guinea pigs,which provided experimental evidence for the safety of full-spectrum lighting.（2）Under the same illuminance,the full-spectrum LED group showed better PRE cell activity and mitochondrial function than the non-full-spectrum LED group,and the changes of axial growth and diopter of guinea pigs were slower,the thickness of retina was higher,the content of DA was higher and the content of 5-HT was lower.（3）Under the same spectral conditions,600 lux is more helpful than 300 lux to slow down the development of myopia in guinea pigs,and it is more obvious in the full-spectrum illumination group:the content of DA is higher,the content of 5-HT is lower,and the change of diopter is slower.In the full-spectrum illumination group,the eye axis of guinea pigs increased more slowly in the high illumination group.（4）Considering the spectrum and illuminance,the full-spectrum illumination 600lux has the best control effect on myopia in this experiment.Figure 23 Table 11 Reference 70... |
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