Effects of mechanical stimulation on viscoelasticity of rabbit scleral fibroblasts after posterior scleral reinforcement

To understand the effect of mechanical stimulation on posterior scleral reinforcement (PSR), rabbit scleral fibroblasts after PSR were subjected to stretch in vitro, and the viscoelastic behavior of scleral fibroblasts was evaluated. Three-week-old rabbits were monocularly treated by eyelid suturation randomly to prepare the experimental myopia eyes. After 60 days, the experimental myopia eyes were treated by PSR. After six months, the posterior pole scleral fibroblasts (normal sclera - group A, sclera after operation - group B and fusion region of sclera and reinforcing band - group C) were isolated and cultured in vitro. The cells were subjected to cyclic stretch regimens (sine wave, 3% and 6% elongation amplitude, 0.1 Hz, 48-h duration) by an FX-4000 Tension System. The micropipette aspiration technique was used to investigate the viscoelasticity of scleral fibroblasts. The cellular viscoelasticity (E-0, E-infinity and mu) of group C was significantly lower than groups A and B (P < 0.05), and there was no significant difference between groups A and B (P > 0.05). The results show that the viscoelasticity in different regions of sclera after PSR is different. Following a 48-h stretch, the cellular viscoelastic parameters were significantly decreased when compared with the respective static groups (P < 0.05) in groups A and B. For group C, the viscoelasticity of the stretch group was significantly higher than the static control group (P < 0.05). There was no difference between the 3% and 6% stretch groups in each group (P > 0.05). The changes of viscoelasticity suggest that different regions of sclera have different responses to mechanical stimulation in the process of treating high myopia by PSR and that mechanical stimulation plays an important role in the treatment of axial myopia by regulating the viscoelasticity of scleral fibroblasts.