Effects of illumination intensity on eye biological parameters,retinal structure,and expression levels of lumican and MMP-2 in scleral tissues of myopic guinea pigs
FU Junda
ZHU Haiping
YANG Wanchen
JIA Na
SUN Yijun
Abstract：Objective To explore the effects of illumination intensity on eye biological parameters,retinal structure,and expression levels of lumican and matrix metalloproteinase-2(MMP-2)in scleral tissues of optical defocus myopia guinea pigs.Methods A total of 80 healthy 3-week-old guinea pigs were selected,regardless of gender.The models of guinea pigs with right-eye optical defocused low to moderate myopia were constructed by concave lens induction method.Among them,60 guinea pigs were randomly selected from 74 successfully modeled guinea pigs and divided into group A,group B,group C and group D,with 15 guinea pigs in each group.The group A was exposed to outdoor sufficient sunlight for 3 hours every day and the average illumination was 60 000 lux.The group B was placed in a cool outdoor place for 3 hours every day and the average illumination was 10 000 lux.The group C were placed at the indoor north window for 3 hours every day and the average illumination was 2 000 lux.The group D was raised indoors normally every day with an average illumination of 300 lux.In the rest of the time,all the guinea pigs were given the same indoor feeding with an average illumination of 300 lux,normal food and water intake,and continuous illumination treatment for 6 months.The ocular biological parameters(axial length and diopter)of the guinea pigs were compared among different groups,and the retinal pathology and ultrastructure of the guinea pigs were observed,and the expression levels of lumican and MMP-2 in the scleral tissues were detected.Results Compared with those before light exposure,the diopter increased in different degrees in each group after 1 month,3 months and 6 months of light exposure,and the group A showed varying degrees of increase in axial length at 3 and 6 months of light exposure,while the group B,the group C and the group D showed varying degrees of increase in axial length at 1,3,and 6 months of light exposure,and the differences were significant(P＜0.05).After 1 month of light exposure,the ocular diopter and axial length in the group A and the group B were lower than those in the group D,and after 3 and 6 months of light exposure,the ocular diopter and axial length in the group A were lower than those in the group B,the group C and the group D,and the ocular diopter and axial length in the group B were lower than those in the group D,and the differences were significant(P＜0.05).The number of apoptotic cells in the group A and the group B was less than that in the group C and the group D,and the number of apoptotic cells in the group A was less than that in the group B,and the differences were significant(P＜0.05).The damage degree of retinal structure in the group A and the group B was milder than that in the group C and the group D,and the damage degree in the group A was milder than that in the group B.After 6 months of light exposure,compared with those in the group C and the group D,the expression levels of lumican were higher and the expression levels of MMP-2 were lower in the group A and the group B,and the expression levels of lumican in the group A were higher than those in the group B,and the expression levels of MMP-2 in the group A were lower than those in the group B,and the differences were significant(P＜0.05).Conclusion Outdoor high-intensity light exposure can up-regulate lumican expression and down-regulate MMP-2 expression in the scleral tissues of guinea pigs,and can stabilize scleral structure,which can slow down the growth of ocular axial length and myopia progression.
Keywords：Illumination intensityMyopia progressionLumicanMatrix metalloproteinaseRetinal structure
Publication Date：2024-03-28
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 296-301 )