Department of Mechanical, Materials and Aerospace Engineering, School of Engineering, University of Liverpool, Liverpool, L69 3GH, UK.
Department of Biomedical Engineering, College of Engineering, University of Babylon, Hillah, Iraq.
Sci Rep. 2019 Apr 19;9(1):6321. doi: 10.1038/s41598-019-42789-4.
There has been a lot of interest in accurately characterising corneal biomechanical properties under intraocular pressure (IOP) to help better understand ocular pathologies that are associated with elevated IOP. This study investigates the novel use of Line-Field Optical Coherence Tomography (LF-OCT) as an elastographic tool for accurately measuring mechanical properties of porcine corneas based on volumetric deformation following varying IOPs. A custom-built LF-OCT was used to measure geometrical and corneal surface displacement changes in porcine corneas under a range of IOPs, from 0-60 mmHg. Corneal thickness, elastic properties and hysteresis were calculated as a function of pressure. In addition, the effects of hydration were explored. We found that the elastic modulus increased in a linear fashion with IOP. Corneal thickness was found to reduce with IOP, decreasing 14% from 0 to 60 mmHg. Prolonged hydration in phosphate buffered saline (PBS) was found to significantly increase the elastic modulus and corneal hysteresis. Our study demonstrates that LF-OCT can be used to accurately measure the elastic properties based on volumetric deformation following physiological pressures. Furthermore, we show that prolonged hydration in PBS has a significant effect on the measured corneal properties.
人们对于准确描述眼压（IOP）下的角膜生物力学特性非常感兴趣，这有助于更好地理解与IOP 升高相关的眼部病变。本研究探索了线阵光学相干断层扫描（LF-OCT）作为一种弹性成像工具的新用途，该工具可根据不同 IOP 下的体积变形，准确测量猪眼角膜的机械性能。使用定制的 LF-OCT 在一系列 IOP（0-60mmHg）下测量猪眼角膜的几何形状和角膜表面位移变化。根据压力计算角膜厚度、弹性特性和滞后性。此外，还探讨了水合作用的影响。我们发现，弹性模量随 IOP 呈线性增加。IOP 会导致角膜厚度减小，从 0mmHg 到 60mmHg 减少 14%。在磷酸盐缓冲盐水（PBS）中长时间水合作用会显著增加弹性模量和角膜滞后性。我们的研究表明，LF-OCT 可用于根据生理压力下的体积变形准确测量弹性特性。此外，我们表明 PBS 中长时间水合作用对测量的角膜特性有显著影响。
