PDF(Pubmed)
Abstract：
BACKGROUND: Although the tissues comprising the ocular conventional outflow pathway have shown strong viscoelastic mechanical response to aqueous humor pressure dynamics, the viscoelastic mechanical properties of the trabecular meshwork (TM), juxtacanalicular connective tissue (JCT), and Schlemm\'s canal (SC) inner wall are largely unknown.
METHODS: A quadrant of the anterior segment from two human donor eyes at low- and high-flow (LF and HF) outflow regions was pressurized and imaged using optical coherence tomography (OCT). A finite element (FE) model of the TM, the adjacent JCT, and the SC inner wall was constructed and viscoelastic beam elements were distributed in the extracellular matrix (ECM) of the TM and JCT to represent anisotropic collagen. An inverse FE-optimization algorithm was used to calculate the viscoelastic properties of the ECM/beam elements such that the TM/JCT/SC model and OCT imaging data best matched over time.
RESULTS: The ECM of the glaucoma tissues showed significantly larger time-dependent shear moduli compared to the heathy tissues. Significantly larger shear moduli were also observed in the LF regions of both the healthy and glaucoma eyes compared to the HF regions.
CONCLUSIONS: The outflow tissues in both glaucoma eyes and HF regions are stiffer and less able to respond to dynamic IOP.
METHODS: A quadrant of the anterior segment from two human donor eyes at low- and high-flow (LF and HF) outflow regions was pressurized and imaged using optical coherence tomography (OCT). A finite element (FE) model of the TM, the adjacent JCT, and the SC inner wall was constructed and viscoelastic beam elements were distributed in the extracellular matrix (ECM) of the TM and JCT to represent anisotropic collagen. An inverse FE-optimization algorithm was used to calculate the viscoelastic properties of the ECM/beam elements such that the TM/JCT/SC model and OCT imaging data best matched over time.
RESULTS: The ECM of the glaucoma tissues showed significantly larger time-dependent shear moduli compared to the heathy tissues. Significantly larger shear moduli were also observed in the LF regions of both the healthy and glaucoma eyes compared to the HF regions.
CONCLUSIONS: The outflow tissues in both glaucoma eyes and HF regions are stiffer and less able to respond to dynamic IOP.
摘要：
背景：尽管包含眼部常规流出途径的组织对房水压力动力学表现出强烈的粘弹性机械反应，小梁网（TM）的粘弹性机械性能，结膜结缔组织（JCT），和Schlemm的运河（SC）内壁在很大程度上是未知的。
方法：在低流量和高流量（LF和HF）流出区域对来自两个人类供体眼的眼前段象限进行加压并使用光学相干断层扫描（OCT）成像。TM的有限元(FE)模型，相邻的JCT，并构建SC内壁，将粘弹性梁元素分布在TM和JCT的细胞外基质（ECM）中以表示各向异性胶原。使用逆FE优化算法来计算ECM/光束元件的粘弹性特性,使得TM/JCT/SC模型和OCT成像数据随时间最佳匹配。
结果：与健康组织相比，青光眼组织的ECM显示出明显更大的时间依赖性剪切模量。与HF区域相比,在健康眼睛和青光眼眼睛的LF区域中也观察到明显更大的剪切模量。
结论：青光眼和HF区域的流出组织都更硬，对动态眼压的反应能力较差。
方法：在低流量和高流量（LF和HF）流出区域对来自两个人类供体眼的眼前段象限进行加压并使用光学相干断层扫描（OCT）成像。TM的有限元(FE)模型，相邻的JCT，并构建SC内壁，将粘弹性梁元素分布在TM和JCT的细胞外基质（ECM）中以表示各向异性胶原。使用逆FE优化算法来计算ECM/光束元件的粘弹性特性,使得TM/JCT/SC模型和OCT成像数据随时间最佳匹配。
结果：与健康组织相比，青光眼组织的ECM显示出明显更大的时间依赖性剪切模量。与HF区域相比,在健康眼睛和青光眼眼睛的LF区域中也观察到明显更大的剪切模量。
结论：青光眼和HF区域的流出组织都更硬，对动态眼压的反应能力较差。
