Protective effects of riboflavin-UVA-mediated posterior sclera collagen cross-linking in a guinea pig model of form-deprived myopia

Effects of riboflavin/ultraviolet-A(UVA) scleral crosslinking on the mechanical behavior of the scleral fibroblasts of lens-induced myopia Guinea pigs

Myopia is becoming increasingly severe, and studies have shown that the cellular mechanics of scleral fibroblasts are altered following myopia. Scleral UVA-Riboflavin Collagen Crosslinking（sCXL） is a promising treatment for myopia prevention and control of axial growth. Understanding the mechanical properties of scleral fibroblasts is crucial, as it influences the cellular response and limits the extent of molecular deformation triggered. Thus, our study aimed to investigate the effect of mechanical properties of scleral fibroblasts in a lens-induced myopic guinea pig model following sCXL. For this purpose, we performed the 0.1% riboflavin/UVA scleral crosslinking (365 nm,3 mW/cm2,30 min) in the right eyes of guinea pigs in Group CXL. In Group LIM, the right eyes were only administrated negative lens for 6 weeks. No treatment was performed in both eyes of the guinea pigs in group Control. The scleral fibroblasts were isolated and cultured from the scleral tissue at the cross-linking area in Group CXL and the corresponding area in Group LIM and control. The curve of the length of microtubules inhaled by cells under negative pressure was measured by a microaspiration-based isolation technique, and the equilibrium Young's modulus and apparent viscosity of scleral fibroblasts were calculated by formula fitting. The equilibrium Young's modulus of scleral fibroblasts in group CXL was significantly lower than that in the LIM group (P < 0.01, two-sample t-test between pairs）, and there was no significant difference between groups CXL and control. The results show that sCXL can effectively moderate the phenomenon that scleral fibroblasts are not easy to deform after myopia. The apparent viscosity modulus in the CXL group was higher than the groups' control and LIM. Taken together, our data demonstrate the biomechanics of the scleral fibroblasts altered after Riboflavin/UVA scleral collagen cross-linking in a lens-induced myopia model.

Effects of air pollution on myopia: an update on clinical evidence and biological mechanisms

Myopia is one of the most common forms of refractive eye disease and considered as a worldwide pandemic experienced by half of the global population by 2050. During the past several decades, myopia has become a leading cause of visual impairment, whereas several factors are believed to be associated with its occurrence and development. In terms of environmental factors, air pollution has gained more attention in recent years, as exposure to ambient air pollution seems to increase peripheral hyperopia defocus, affect the dopamine pathways, and cause retinal ischemia. In this review, we highlight epidemiological evidence and potential biological mechanisms that may link exposure to air pollutants to myopia. A thorough understanding of these mechanisms is a key for establishing and implementing targeting strategies. Regulatory efforts to control air pollution through effective policies and limit individual exposure to preventable risks are required in reducing this global public health burden.