Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham, AL 35233, USA.
Departments of Ophthalmology and Integrative Biosciences, Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA.
Cells. 2022 Dec 4;11(23):3925. doi: 10.3390/cells11233925.
A layer of proteoglycans and glycoproteins known as glycocalyx covers the surface of the trabecular meshwork (TM), juxtacanalicular tissue (JCT), and Schlemm's canal (SC) inner wall of the conventional aqueous outflow pathway in the eye. This has been shown to play a role in the mechanotransduction of fluid shear stress and in the regulation of the outflow resistance. The outflow resistance in the conventional outflow pathway is the main determinant of the intraocular pressure (IOP) through an active, two-way, fluid-structure interaction coupling between the outflow tissues and aqueous humor. A 3D microstructural finite element (FE) model of a healthy human eye TM/JCT/SC complex with interspersed aqueous humor was constructed. A very thin charged double layer that represents the endothelial glycocalyx layer covered the surface of the elastic outflow tissues. The aqueous humor was modeled as electroosmotic flow that is charged when it is in contact with the outflow tissues. The electrical-fluid-structure interaction (EFSI) method was used to couple the charged double layer (glycocalyx), fluid (aqueous humor), and solid (outflow tissues). When the IOP was elevated to 15 mmHg, the maximum aqueous humor velocity in the EFSI model was decreased by 2.35 mm/s (9%) compared to the fluid-structure interaction (FSI) model. The charge or electricity in the living human conventional outflow pathway generated by the charged endothelial glycocalyx layer plays a minor biomechanical role in the resultant stresses and strains as well as the hydrodynamics of the aqueous humor.
在眼睛的传统房水流出途径中,一层由蛋白聚糖和糖蛋白组成的糖萼覆盖在小梁网(TM)、近小管组织(JCT)和施莱姆氏管(SC)内壁表面。现已证实,糖萼在流体切应力的机械转导以及流出阻力的调节中发挥作用。在传统流出途径中,流出阻力是通过流出组织和房水之间的主动、双向、流固结构相互作用耦合来决定眼内压(IOP)的主要因素。构建了具有交错房水的健康人眼 TM/JCT/SC 复合体的三维微观结构有限元(FE)模型。一个非常薄的带电双层,代表着覆盖弹性流出组织表面的内皮糖萼层。房水被建模为当与流出组织接触时带有电荷的电渗流。采用电-流-固相互作用(EFSI)方法来耦合带电双层(糖萼)、流体(房水)和固体(流出组织)。当眼压升高至 15mmHg 时,与流固相互作用(FSI)模型相比,EFSI 模型中的房水最大速度降低了 2.35mm/s(9%)。由带电荷的内皮糖萼层产生的活体人传统流出途径中的电荷或电在房水的应力、应变和流体动力学中仅起到次要的生物力学作用。