Chen Kinon, Rowley Adrian P, Weiland James D, Humayun Mark S
Department of Biomedical Engineering, University of Southern California, Denney Research Center 140, 1042 Downey Way, Los Angeles, California, 90089; Department of Ophthalmology, University of Southern California, Doheny Eye Institute, 1450 San Pablo Street, Los Angeles, California, 90033.
J Biomed Mater Res A. 2014 Jun;102(6):2001-7. doi: 10.1002/jbm.a.34858. Epub 2013 Aug 17.
This study examines the elastic properties of the human posterior retina, choroid, and sclera. Twenty-four human eyes from 30- to 74-year-old donors were obtained from an eye bank. Vertically and horizontally oriented tissue strips of the retina, choroid, and sclera (ideally n = 12 in each group) were harvested from the posterior eyes. Their thicknesses were estimated optically. The samples were stretched at 1 mm/s in 37°C saline. Stress and strain were obtained from the mechanical tests, and then the transition stress, transition strain, toe modulus, and heel modulus were calculated. Statistical analysis was performed for comparison between groups. Linear regression analyses were used to explore the relationship between the mechanical parameters and age. We found that the stress-strain relationship of the retina, choroid, and sclera were nonlinear. Except for the retinal transition strain (p = 0.0124), no statistical difference was found between the vertical and horizontal meridian in the mechanical parameters (p > 0.05). Furthermore, weak relationship was observed between some of the mechanical parameters and the donors' age. Our results suggest that there is significant anisotropy in the retina, and mechanical properties of each layer may change with age.
本研究检测了人眼后部视网膜、脉络膜和巩膜的弹性特性。从眼库获取了24只来自30至74岁供体的人眼。从眼后部获取视网膜、脉络膜和巩膜垂直和水平方向的组织条（每组理想数量为n = 12）。通过光学方法估计其厚度。样本在37°C盐水中以1 mm/s的速度拉伸。从力学测试中获得应力和应变，然后计算转变应力、转变应变、起始模量和终末模量。进行统计分析以比较组间差异。采用线性回归分析来探究力学参数与年龄之间的关系。我们发现视网膜、脉络膜和巩膜的应力-应变关系是非线性的。除视网膜转变应变外（p = 0.0124），力学参数在垂直和水平子午线之间未发现统计学差异（p > 0.05）。此外，部分力学参数与供体年龄之间存在弱相关性。我们的结果表明，视网膜存在显著的各向异性，且各层的力学特性可能随年龄变化。
