Scleral biomechanics in the aging monkey eye.
Scleral biomechanics in the aging monkey eye.
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DOI：
10.1167/iovs.08-3363
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发表时间：
2009-11
影响因子：
4.4
通讯作者：
Downs JC
中科院分区：
文献类型：
--
作者：
Girard MJ;Suh JK;Bottlang M;Burgoyne CF;Downs JC
研究老年恒河猴（22.9 ± 5.3岁）和青年恒河猴（1.5 ± 0.7岁）后巩膜的非均匀性、各向异性和非线性生物力学特性的年龄差异。将每只眼睛的后巩膜壳安装在定制的加压装置上，然后将眼内压（IOP）从5升高至45 mmHg，同时使用散斑干涉法测量巩膜表面的3D位移。根据3D数字化仪（地形图）和20 MHz超声（厚度）生成的数据对每个巩膜壳几何结构进行数字重建。一个逆有限元（FE）方法，结合纤维增强的本构模型被用来提取一组独特的生物力学性能为每只眼睛。位移，厚度，应力，应变，切线模量，结构刚度，和首选胶原纤维取向映射为每个后巩膜。该模型产生的后巩膜的三维变形，以及与实验观察到的。后巩膜表现出不均匀、各向异性、非线性的力学行为。老年猴的巩膜明显更薄（p = 0.038），切线模量和结构刚度明显更高（p < 0.0001）。平均而言，巩膜胶原纤维围绕视神经乳头（ONH）周向定向。我们没有发现年龄组之间的首选胶原纤维取向和纤维浓度因子的差异。老年猴的后巩膜比年轻猴的后巩膜明显更硬，因此在所有IOP水平下都受到更高的应力但更低的应变。与年龄相关的巩膜硬化可能会显著影响ONH的生物力学，并可能导致与年龄相关的昏迷性视力丧失的易感性。
To investigate the age-related differences in the inhomogeneous, anisotropic, nonlinear biomechanical properties of posterior sclera from old (22.9 ± 5.3 years) and young (1.5 ± 0.7 years) rhesus monkeys. The posterior scleral shell of each eye was mounted on a custom-built pressurization apparatus, then intraocular pressure (IOP) was elevated from 5 to 45 mmHg while the 3D displacements of the scleral surface were measured using speckle interferometry. Each scleral shell geometry was digitally reconstructed from data generated by a 3D digitizer (topography) and 20 MHz ultrasounds (thickness). An inverse finite element (FE) method incorporating a fiber-reinforced constitutive model was used to extract a unique set of biomechanical properties for each eye. Displacements, thickness, stress, strain, tangent modulus, structural stiffness, and preferred collagen fiber orientation were mapped for each posterior sclera. The model yielded 3-D deformations of posterior sclera that matched well with those observed experimentally. The posterior sclera exhibited inhomogeneous, anisotropic, nonlinear mechanical behavior. The sclera was significantly thinner (p = 0.038), and tangent modulus and structural stiffness were significantly higher in old monkeys (p < 0.0001). On average, scleral collagen fibers were circumferentially oriented around the optic nerve head (ONH). We found no difference in the preferred collagen fiber orientation and fiber concentration factor between age groups. Posterior sclera from old monkeys is significantly stiffer than that from young monkeys and is therefore subject to higher stresses but lower strains at all levels of IOP. Age-related stiffening of the sclera may significantly influence ONH biomechanics, and potentially contribute to age-related susceptibility to glaucomatous vision loss.
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影响因子：
4.1
作者：
Albon, J;Karwatowski, WSS;Duance, VC
通讯作者：
Duance, VC
影响因子：
3.9
作者：
Foster, A;Resnikoff, S
通讯作者：
Resnikoff, S
影响因子：
3.4
作者：
Cui, W;Bryant, MR;McDonnell, PJ
通讯作者：
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影响因子：
1.8
作者：
Chen Weiyi;Wang Xiaojun;Zhang Quanyou
通讯作者：
Zhang Quanyou
影响因子：
4.1
作者：
ALBON, J;KARWATOWSKI, WSS;DUANCE, VC
通讯作者：
DUANCE, VC