Mechanical behavior of scleral fibroblasts in experimental myopia.

BACKGROUND

The study aims to determine the changes in the biomechanical properties of the anterior and extreme posterior portions of experimental near-sighted eyes by examining the mechanical behavior of guinea pig scleral desmocytes, thus finding a new approach to the pathogenesis of myopia and their corresponding therapies.

METHODS

Guinea pigs (2 weeks old) were numbered and assigned into three groups (A, B, and C) with ten guinea pigs each. Concave lens-induced myopic (LIM) animal models were prepared via the out-of-focus method. The other eye in the same guinea pig served as the self-control (SC) group. After modeling groups A, B, and C for 6, 15, and 30 days respectively, the lenses from the guinea pigs in the experimental group were removed. The scleral fibroblasts in each group were cultured, and passaged twice in vitro. The micropipette aspiration technique coupled with a viscoelastic solid model was utilized to investigate the viscoelastic properties of the scleral fibroblasts in normal and myopic guinea pigs. The mechanical behavior of the scleral desmocytes of the LIM and SC groups were compared.

RESULTS

The mechanical behavior of the scleral desmocytes was compared between the LIM and SC groups. The Young's modulus at equilibrium and the apparent cellular viscosity of the anterior portion of the sclera in the LIM group at 6 days and 15 days after myopic induction were not significantly different from that of the SC group (P < 0.05). However, the results for the anterior portions of the sclera in the LIM group at 30 days were significantly higher than those of the LIM group at 6 and 15 days, as well as those in the SC group (P < 0.05). The Young's modulus at equilibrium and the apparent cellular viscosity of the extreme posterior portions of the sclera in the LIM group at 6 days after myopic induction not significantly from those of the SC group (P < 0.05). However, the results for the extreme posterior portions of the sclera in the LIM group after 15 days and 30 days were significantly higher than those in the LIM group at 6 days and the SC group (P < 0.05).

CONCLUSIONS

The Young's modulus at equilibrium or apparent cellular viscosity of all the anterior portions of the sclera in the LIM group were longer than those in the SC group at 30 days after the induction, and the results for all the extreme posterior portions of the LIM group were larger than those of the SC group on the 15th and 30th day. Therefore, the Young's modulus and apparent viscosity of the anterior and extreme posterior portions of the sclera changed on the 15th and 30th day after induction respectively.