Effect Of Different Color Temperature Visible Light Illumination On Guinea Pig Visual Development

Objective: To observe the effect of different color temperature visible light illumination on guinea pig visual development,to study the effect of different color temperature visible light illumination on the expression of dopamine in guinea pig retina,to explore the mechanism of different color temperature visible light illumination on the visual development of guinea pig and to explore the most suitable visible light illumination for children and adolescents.Methods: Seventy-two guinea pigs of 3 weeks old were randomly divided into four groups according to the random number table: the control group,the yellow light group,the warm white light group and the white light group,each with 18 rats.Guinea pigs in the control group were exposed to natural light(The average illuminance of the light source was 680 lux)for 12 h everyday.Guinea pigs in the yellow light group were exposed to yellow light LED with color temperature of 3000K(red 615 nm,green 515 nm and blue 465 nm mixed,illuminance of light was 680 lux)for 12 h everyday.Guinea pigs in the warm white light group were exposed to warm white light LED with color temperature of 4000K(red 615 nm,green 515 nm and blue 465 nm mixed,illuminance of light was 680 lux)for 12 h everyday.Guinea pigs in the white light group were exposed to white light LED with color temperature of 6500K(red 615 nm,green 515 nm and blue 465 nm mixed,illuminance of light was 680 lux)for 12 h everyday.Before the intervention,4 weeks and 8 weeks after the intervention,the length of the eye axis of the guinea pig was measured by A/ B ultrasound,the diopter of the guinea pig was measured by the strip light microscope,the corneal curvature radius of the guinea pig was measured by the keratometer,and the content of dopamine in the retina was measured by high-pressure liquid chromatography electrochemistry.Results:There were no significant differences in the axial length,lens thickness and vitreous cavity length among the four groups before intervention(Faxial length=0.082、Flens thickness=0.048、Fvitreous cavity length=0.182,P > 0.05).The axial length and vitreous cavity length of the yellow light group were significantly longer than those of the other three groups at 4 and 8 weeks after intervention.The differences were statistically significant(Faxial length=8.002、Fvitreous cavity length=3.407,Faxial length=17.103、Fvitreous cavity length=7.491,all P<0.05).There were no significant differences between the control group and the warm white light group and the white light group(all P > 0.05).There were no significant differences in the lens thickness among the four groups at 4 and 8 weeks after intervention(Flens thickness=0.133、Flens thickness=0.184,P > 0.05).There were no significant differences in the diopter among the four groups before intervention(Fdiopter=0.01,P > 0.05).The diopter of the yellow light group was significantly lower than that of the other three groups at 4 and 8 weeks after intervention.The differences were statistically significant(Fdiopter=1.764、Fdiopter=3.969,all P<0.05).There were no significant differences between the control group and the warm white light group and the white light group(all P > 0.05).There were no significant differences in the corneal curvature radius among the four groups before intervention,4 and 8 weeks after intervention(F corneal curvature radius=0.572、Fcorneal curvature radius=0.138、Fcorneal curvature radius=0.032,P > 0.05).There were no significant differences in the content of dopamine in the retina among the four groups before intervention(Fdopamine content=0.000,P > 0.05).The content of dopamine in the retina of the yellow light group were significantly lower than those of the other three groups at 4 and 8 weeks after intervention.The differences were statistically significant(Fdopamine content=F=3.264、Fdopamine content=6.248,all P<0.05).There were no significant differences between the control group and the warm white light group and the white light group(all P > 0.05).Conclusion :The yellow light with low color temperature promotes the axial length growth of guinea pig,and the diopter shifts to myopia.Warm white light with moderate color temperature and white light with high color temperature promote the development of emmetropia.The yellow light with low color temperature causes the decrease of dopamine content in the retina of guinea pigs.This may be one of the mechanisms of myopia in guinea pigs.The warm white light with medium color temperature(color temperature is 4000K)may be a suitable light source for children and adolescents to learn.