Study of the effects of rabbit scleral fibroblasts on cellular biomechanical properties and MMP-2 expression using two modes of riboflavin/ultraviolet A wave collagen cross-linking

Abstract Objective The aim of this study is to evaluate the cellular biomechanical properties and MMP-2 expression changes in rabbit scleral fibroblasts using two modes of riboflavin and ultraviolet A (UVA) collagen cross-linking (CXL). Methods Twenty-four New Zealand white rabbits were randomly divided into two groups, A and B. The left eye was chosen for the experimental group and the right eye for the control group. In group A, the eyes were irradiated for 30 min, with a power density of 3.0 mW/cm2. In group B, the eyes were irradiated for 9 min, with a power density of 10.0 mW/cm2. One week after CXL, full-field electroretinography was performed. Sixty days after CXL, the rabbits were sacrificed, and scleral fibroblasts were extracted from the CXL-treated sclera area and corresponding parts of control sclera and cultured. Cellular biomechanical properties were evaluated using the micropipette aspiration technique, and the MMP-2 protein expression was determined by Western blot analysis. Results There was no statistical difference in the amplitude and latency of the dark adaptation 3.0 and light adaptation 3.0 between the CXL and control eyes of groups A and B (P > 0.05). Compared with the control groups, the Young's modulus of the fibroblasts and apparent viscosity of the experimental eyes in groups A and B were increased after CXL (P   0.05). The MMP-2 expression in scleral fibroblasts from experimental eyes was significantly higher than that in scleral fibroblasts from control eyes in groups A and B. Under the two different irradiation modes, the MMP-2 expression in the scleral fibroblasts from experimental eyes in group A was significantly higher than that in the scleral fibroblasts from experimental eyes in group B. Conclusion The riboflavin-UVA scleral CXL conducted in two different modes produced no significant side effects on the retina and could strengthen the cell biomechanical properties as well as increase the MMP-2 expression of scleral fibroblasts significantly.