The collagen metabolism affects the scleral mechanical properties in the different processes of scleral remodeling

To increase the understanding of collagen metabolism as related to scleral remodeling in the process of emmetropization and myopization. An eyelid suture that lasted 60 days was performed on one-month-old rabbits to establish an experimental monocular visual deprivation myopia model and the axial length was recorded. HE staining and transmission electron microscope were used to observe the scleral structure. The Instron 5544 was used to measure scleral elastic modulus after measuring the scleral thickness. The content of scleral tissue collagen was determined by detecting the hydroxyproline quantity and the collagen I α1, MMP-2, and TIMP-2 mRNA expression were detected by RT-PCR Kit. During regular emmetropization, the scleral collagen synthesis was higher than decomposition and the diameter of collagen fibrils increased, and then the sclera thickened and mechanical properties improved. During myopization, the scleral collagen decomposition was higher than synthesis and the diameter of collagen fibrils was smaller, and then the sclera thinner and mechanical properties lower, which resulted in a difference in scleral tissue strain. The results suggested that there were different scleral remodeling process between the emmetropization and myopization, and the collagen metabolism affected the scleral mechanical properties and scleral remodeling and then affected the scleral growth, axial elongation, and even myopization.