Changes in the Biomechanical Response of the Optic Nerve Head in Early Experimental Glaucoma
Changes in the Biomechanical Response of the Optic Nerve Head in Early Experimental Glaucoma
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DOI：
10.1167/iovs.10-5411
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发表时间：
2010-11-01
影响因子：
4.4
通讯作者：
Downs, J. Crawford
中科院分区：
文献类型：
--
作者：
Roberts, Michael D.;Sigal, Ian A.;Downs, J. Crawford
目的.在3对猴眼（其中1只患眼为实验性青光眼（EG））模型上，研究视神经乳头（ONH）结缔组织对眼压升高的生物力学反应。一系列成像技术被用来重建ONH和视乳头周围巩膜的三对单侧EG眼睛固定在10毫米汞柱。眼特定的有限元模型的后极构造与不均匀的材料特性定义的筛板（LC）的基础上，局部结缔组织体积分数（CTVF）和主要的LC光束方向。这些模型用于模拟IOP从10 mm Hg增加至45 mm Hg。改变层状材料常数以产生一系列LC位移和巩膜管扩张，并表征相关的LC应力和应变。该模型表明，正常和EG眼的LC可以向后或向前变形时，LC材料刚度低或高，分别。巩膜管扩张在EG眼中通常但不总是减少。对于相同的平均LC位移，EG眼的应变与对侧眼的应变相似或低于对侧眼的应变，并且当LC更柔顺时，EG眼的应变增加。无论LC的硬度如何，EG眼的层压应力始终较低。EG中的结缔组织重塑以眼特异性方式改变LC对IOP升高的生物力学反应。模型显示，在三只猴中，有两只的EG眼的LC组织比对侧正常眼的LC组织更丰富。（Invest Ophthalmol维斯科学。2010;51：5675-5684）DOI：10.1167/iovs.10-5411
PURPOSE. To investigate the biomechanical response of the optic nerve head (ONH) connective tissues to IOP elevation in three pairs of monkey eyes in which one eye had early experimental glaucoma (EG).METHODS. A serial imaging technique was used to reconstruct the ONH and peripapillary sclera of three pairs of unilateral EG eyes fixed at 10 mm Hg. Eye-specific finite element models of the posterior pole were constructed with inhomogeneous material properties defined for the lamina cribrosa (LC) based on local connective tissue volume fraction (CTVF) and predominant LC beam orientation. These models were used to simulate an IOP increase from 10 to 45 mm Hg. A laminar material constant was varied to produce a range of LC displacements and scleral canal expansions, and the associated LC stress and strain were characterized.RESULTS. The models suggest that the LC of normal and EG eyes can deform posteriorly or anteriorly when the LC material stiffness is low or high, respectively. Scleral canal expansion was generally, but not always, reduced in EG eyes. Strains in the EG eye were similar to or lower than those in the contralateral eye for the same average LC displacement and increased when the LC was more pliant. Laminar stresses were consistently lower in the EG eye, regardless of LC stiffness.CONCLUSIONS. Connective tissue remodeling in EG alters the biomechanical response of the LC to IOP elevation in an eye- specific manner. The models indicated that the LC tissues in EG eyes were more plaint than those in the contralateral normal eyes in two of three monkeys. (Invest Ophthalmol Vis Sci. 2010;51:5675-5684) DOI:10.1167/iovs.10-5411