Hjortdal J O
Department of Ophthalmology, Arhus University Hospital, Denmark.
Acta Ophthalmol Scand. 1995 Feb;73(1):12-7. doi: 10.1111/j.1600-0420.1995.tb00005.x.
The extensibility of 10 human corneas was evaluated in vitro by measuring central epithelial side and endothelial side tangential strain induced by intraocular pressure loads ranging from 2 to 100 mmHg. Corneal normo-hydration was attempted by immersing and perfusing the eyes with 8% Dextran 500 in isotonic saline. The relationship between corneal strain and intraocular pressure was found to be non-linear, showing a typical stress-stiffening behaviour. Strain changes were approximately 10% higher on the endothelial side compared with the epithelial side. This difference could be fully explained by pressure induced changes in corneal volume. Compared to previous experiments performed on swollen corneas, the stiffness of the normo-hydrated human cornea was found to be higher. Young's modulus of elasticity for the corneal stroma was estimated to 3, 9, and 20 MPa for intraocular pressure intervals of 2-10, 10-25, and 25-100 mmHg, respectively.
通过测量2至100 mmHg眼内压负荷引起的中央上皮侧和内皮侧切向应变，在体外评估了10个人类角膜的伸展性。通过用等渗盐水中的8%右旋糖酐500浸泡和灌注眼睛来尝试实现角膜正常水化。发现角膜应变与眼内压之间的关系是非线性的，呈现出典型的应力硬化行为。内皮侧的应变变化比上皮侧高约10%。这种差异可以通过压力引起的角膜体积变化得到充分解释。与之前在肿胀角膜上进行的实验相比，发现正常水化的人类角膜硬度更高。对于2-10、10-25和25-100 mmHg的眼内压区间，角膜基质的杨氏弹性模量分别估计为3、9和20 MPa。
