Circumferential Tensile Stiffness of Glaucomatous Trabecular Meshwork
Circumferential Tensile Stiffness of Glaucomatous Trabecular Meshwork
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DOI：
10.1167/iovs.13-13091
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发表时间：
2014-02-01
影响因子：
4.4
通讯作者：
Yuan, Fan
中科院分区：
文献类型：
--
作者：
Camras, Lucinda J.;Stamer, W. Daniel;Yuan, Fan
目的.我们以前的工作表明，在正常人供体眼中，小梁网（TM）的周向杨氏模量（E）较大与外流便利度（C）较高相关。目前的研究调查了昏迷TM刚度和细胞结构对C。方法。在死后48小时内灌注来自昏迷的人类供体的八只左眼。在10、20、30和40 mm Hg的压力下测定C值。然后将TM解剖并用光学相干断层扫描成像以确定其横截面积。对TM节段纵向施加单轴拉伸应力，以确定应力-应变曲线。在零应变下计算E，表示TM在松弛状态下的周向刚度。DAPI染色的TM片段的共聚焦图像用于确定机械拉伸后的细胞结构。在10 mm Hg时，青光眼眼的C（μ L/min/mm Hg）为0.18 +/- 0.02（平均值+/- SE），当压力增加到40 mm Hg时，降低到0.11 +/- 0.02。在30和40毫米汞柱下测量的C与TM细胞结构相关。E为12.5 MPa和1.4（几何平均值和SE），与死后时间、年龄、C或细胞数无统计学相关性。与正常眼相比，青光眼眼的C值明显降低，且降低量随压力的增加而增加。昏迷TM的E约为正常TM的1/5。需要进行前瞻性研究以进一步研究TM拉伸刚度对流出调节的影响。
PURPOSE. Our previous work indicated that a larger circumferential Young's modulus (E) of trabecular meshwork (TM) correlated with a higher outflow facility (C) in normal human donor eyes. The current study investigated the influence of glaucomatous TM stiffness and cellularity on C.METHODS. Eight left eyes from glaucomatous human donors were perfused within 48 hours post mortem. Values of C were determined at pressures of 10, 20, 30, and 40 mm Hg. The TM was then dissected and imaged with optical coherence tomography to determine its cross-sectional area. Uniaxial tensile stress was applied longitudinally to TM segments to determine stress-strain curves. E was calculated at zero strain, representing the circumferential stiffness of the TM at a relaxed state. Confocal images of DAPI-stained TM segments were used to determine cellularity after mechanical stretching.RESULTS. C (mu L/min/mm Hg) of glaucomatous eyes was 0.18 +/- 0.02 (mean +/- SE) at 10 mm Hg and decreased to 0.11 +/- 0.02 when the pressure was increased to 40 mm Hg. C measured at 30 and 40 mm Hg correlated with TM cellularity. E was 12.5 MPa and 1.4 (geometric mean and SE) and did not statistically correlate with postmortem time, age, C, or cellularity.CONCLUSIONS. Compared with data of normal eyes observed in a previous study, C in glaucomatous eyes was reduced significantly, and the amount of reduction increased with increasing the pressure. E of glaucomatous TM was approximately one-fifth that of normal TM. Prospective studies are needed to further investigate the influence of TM tensile stiffness on outflow regulation.