Experimental assessment of human corneal hysteresis
Experimental assessment of human corneal hysteresis
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DOI：
10.1080/02713680701882519
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发表时间：
2008-03-01
影响因子：
2
通讯作者：
Garway-Heath, David
中科院分区：
文献类型：
--
作者：
Elsheikh, Ahmed;Wang, Defu;Garway-Heath, David
目的：滞后是一种粘弹性，其特征是加载和卸载下行为的差异。该研究的目的是通过实验手段确定角膜滞后。方法：对 29 名 50-95 岁的人角膜进行循环压力加载和卸载。采用两种压力施加率来近似静态和动态负载条件。结果：随着年龄的增长，加载和卸载下的行为都会变得僵硬。卸载行为似乎在很大程度上与卸载开始时的压力水平无关。加载和卸载下行为模式之间的差异被量化并用作角膜滞后的测量。随着加载速度的加快和使用年限的缩短，滞后面积显着增大。结论：滞后现象随着年龄的增长而减少的趋势与之前的临床观察结果一致。还发现滞后随着压力施加的加快而增加。
Purpose: Hysteresis is a viscoelastic property characterized by the difference in behavior under loading and unloading. The aim of the study was to determine corneal hysteresis using experimental means. Methods: Twenty-nine human corneas with 50-95 year age were subjected to cycles of pressure loading and unloading. Two pressure application rates were adopted to approximate static and dynamic loading conditions. Results: The behavior under both loading and unloading was found to stiffen with increased age. The unloading behavior appeared to be largely independent of the pressure level at which unloading started. The difference between the behavior patterns under loading and unloading was quantified and used as a measure of corneal hysteresis. The hysteresis area was significantly larger with faster loading and with decreased age. Conclusions: The trend for hysteresis to decrease with age is in agreement with previous clinical observations. Hysteresis was also found to increase with faster pressure application.