From Biomedical Engineering (Singh, Li, Larin) and the College of Optometry (Vantipalli), Mechanical Engineering (Aglyamov), University of Houston, and Molecular Physiology and Biophysics (Larin), Baylor College of Medicine, Houston, Texas, and the School of Optometry (Twa) and Biomedical Engineering (Twa), University of Alabama at Birmingham, Birmingham, Alabama, USA; The School of Naval Architecture (Han), Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai, China; Interdisciplinary Laboratory of Biophotonics (Larin), Tomsk State University, Tomsk, Russia.
From Biomedical Engineering (Singh, Li, Larin) and the College of Optometry (Vantipalli), Mechanical Engineering (Aglyamov), University of Houston, and Molecular Physiology and Biophysics (Larin), Baylor College of Medicine, Houston, Texas, and the School of Optometry (Twa) and Biomedical Engineering (Twa), University of Alabama at Birmingham, Birmingham, Alabama, USA; The School of Naval Architecture (Han), Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai, China; Interdisciplinary Laboratory of Biophotonics (Larin), Tomsk State University, Tomsk, Russia.
J Cataract Refract Surg. 2018 Aug;44(8):1023-1031. doi: 10.1016/j.jcrs.2018.03.036. Epub 2018 Jul 23.
To quantify the effects of the hydration state on the Young's modulus of the cornea.
Biomedical Optics Laboratory, University of Houston, Houston, Texas, USA.
Experimental study.
Noncontact, dynamic optical coherence elastography (OCE) measurements were taken of in situ rabbit corneas in the whole eye-globe configuration (n = 10) and at an artificially controlled intraocular pressure of 15 mm Hg. Baseline OCE measurements were taken by topically hydrating the corneas with saline for 1 hour. The corneas were then dehydrated topically with a 20% dextran solution for another hour, and the OCE measurements were repeated. A finite element method was used to quantify the Young's modulus of the corneas based on the OCE measurements.
The thickness of the corneas shrank considerably after topical addition of the 20% dextran solution (∼680 μm to ∼370 μm), and the OCE-measured elastic-wave speed correspondingly decreased (∼3.2 m/s to ∼2.6 m/s). The finite element method results showed an increase in Young's modulus (500 kPa to 800 kPa) resulting from dehydration and subsequent thinning.
Young's modulus increased significantly as the corneas dehydrated and thinned, showing that corneal geometry and hydration state are critical factors for accurately quantifying corneal biomechanical properties.
定量评估角膜水合状态对杨氏模量的影响。
美国德克萨斯州休斯顿市休斯顿大学生物医学光学实验室。
实验研究。
对原位兔眼角膜进行非接触式动态光相干弹性成像（OCE）测量，采用全眼球配置（n=10），并在人工控制的 15mmHg 眼内压下进行。通过局部滴注生理盐水使角膜水化 1 小时，进行基线 OCE 测量。然后，用 20%葡聚糖溶液局部使角膜脱水 1 小时，重复 OCE 测量。根据 OCE 测量结果，采用有限元法定量评估角膜杨氏模量。
局部滴注 20%葡聚糖溶液后，角膜厚度明显收缩（680μm 至370μm），OCE 测量的弹性波速度相应降低（3.2m/s 至2.6m/s）。有限元法结果显示，由于脱水和随后的变薄，杨氏模量增加（500kPa 至 800kPa）。
角膜脱水变薄时杨氏模量显著增加，表明角膜几何形状和水合状态是准确量化角膜生物力学特性的关键因素。
