高眼压作用下大鼠小梁网组织弹性模量的变化

The elastic modulus changes of trabecular meshwork in rats under high intraocular pressure

目的探究高眼压持续作用不同时间下大鼠小梁网组织弹性模量的变化情况,为深入研究小梁网组织的力学特性与房水外流阻力之间的关系提供基础。方法选取18只SD雄性大鼠,体重控制在260~300 g。右眼通过烙闭上巩膜静脉建立高眼压实验组模型,左眼不做任何处理作为对照组,并分别在2周、3周、4周取下眼球后制作小梁网组织横截面冰冻切片,利用原子力显微镜对小梁网区域进行纳米压痕实验,使用Sneddon接触模型对压痕曲线进行拟合,得到高眼压作用持续不同时间下小梁网弹性模量的变化情况。结果实验组与对照组眼压差异具有显著性,说明成功建立了高眼压动物模型。2周、3周、4周实验组的小梁网弹性模量分别为(20.55±5.68)kPa、(23.98±4.42)kPa、(28.56±5.94)kPa,明显大于各自的对照组,且不同时间点3个实验组的小梁网组织弹性模量也存在统计学上的差异。结论随着高眼压的持续作用,小梁网组织弹性模量明显增大,且与作用时间呈正相关。这一发现一定程度上考虑了高眼压对小梁网力学性质的影响,为深入了解高眼压对眼球生理机制的影响提供了重要线索,所得结果对房水外流阻力增大机制的研究具有参考意义。

Objective To investigate the changes in the elastic modulus of the trabecular meshwork tissue in rats under sustained high intraocular pressure at different time intervals.This study aims to provide a foundation for a deeper understanding of the mechanical properties of the trabecular meshwork tissue and its relationship with aqueous humor outflow resistance.Methods Eighteen male SD rats weighing between 260-300 g were selected.The experimental group underwent elevated intraocular pressure by cauterizing the superior venous angle in the right eye,while the left eye served as the control without any treatment.Eyes were enucleated at 2 weeks,3 weeks,and 4 weeks for frozen cross-sectional slices of the trabecular meshwork tissue.Nanoindentation experiments were conducted using atomic force microscopy in the trabecular meshwork region.The indentation curves were fitted using the Sneddon contact model to determine the changes in the elastic modulus of the trabecular meshwork under different durations of elevated intraocular pressure.Results There was a significant difference in intraocular pressure between the experimental and control groups,indicating the successful establishment of the high intraocular pressure animal model.Specifically,the elastic modulus of the trabecular meshwork in the experimental groups at 2 weeks,3 weeks,and 4 weeks were(20.55±5.68)kPa,(23.98±4.42)kPa,and(28.56±5.94)kPa,respectively,significantly higher than their respective control groups.Additionally,there were statistical differences in the elastic modulus of the trabecular meshwork tissue among the three experimental groups at different time points.Conclusions The results suggest that with the sustained impact of high intraocular pressure,the elastic modulus of the trabecular meshwork tissue significantly increases,showing a positive correlation with the duration of exposure.This finding contributes to understanding the mechanical effects of elevated intraocular pressure on the trabecular meshwork,providing valuable insights into the physiological mechanisms influenced by high intraocular pressure and offering reference significance for studying the mechanisms of increased aqueous humor outflow resistance.