In vivo high-resolution mapping of the elastic moduli and tensile stress in the human cornea

摘要 角膜中弹性性质和张力之间的机械平衡在角膜的形成中起关键作用。 正常视力、屈光矫正手术、青光眼筛查和圆锥角膜的管理。 几种实验和商业仪器是可用的，它们提供了临床数据， 提示生物力学分析的潜在价值。然而，这些设备提供有限的定量 分辨率，并且不能表征高度各向异性、非线性和 不均匀。该项目的总体目标是推进光学相干弹性成像（OCE）， 利用这项技术测量人类角膜的力学参数，具有前所未有的细节。 建立在强大的初步数据，新的OCE利用拉伸和弯曲弹性波引导 沿着角膜，并根据轮廓确定拉伸模量和剪切模量以及张力 和波的速度。第一个具体目标是利用猪和人来开发宽带OCE 离体尸体眼睛。高精度和高分辨率量化弹性模量和张力的算法 将被核实。第二个具体目标将应用宽带OCE从以下位置获得详细的力学数据： 人体角膜该研究将涉及整个生命周期的健康受试者，高眼压 患者、圆锥角膜患者和经历屈光手术的受试者。这一潜在影响 该项目是巨大的，因为预期的数据将提高我们对角膜生物力学的理解， 与各种自然、病理和介入过程以及技术进步的关系 可能导致一种新的临床工具，可以提高圆锥角膜的诊断和治疗，准确性 以及屈光手术的安全性和视力结果。

ABSTRACT The mechanical balance between the elastic properties and tension in the cornea plays a critical role in normal vision, refractive corrective surgery, glaucoma screening, and the management of keratoconus. Several experimental and commercial instruments are available, and they have provided clinical data that suggest the potential values of biomechanical analysis. However, these devices offer limited quantitative resolution and cannot characterize corneal elastic properties that are highly anisotropic, nonlinear, and nonuniform. The overarching goal of this project is to advance optical coherence elastography (OCE) and use this technology to measure the mechanical parameters in human corneas with unprecedented details. Built on strong preliminary data, the new OCE harnesses extensional and flexural elastic waves guided along the cornea and determines tensile modulus and shear modulus, as well as tension, from the profiles and velocities of the waves. The first specific aim will develop wideband OCE using porcine and human cadaver eyes ex vivo. Algorithms to quantify elastic moduli and tension with high precision and resolution will be verified. The second specific aim will apply wideband OCE to obtain detailed mechanical data from human corneas in vivo. The study will involve healthy subjects across the lifespan, ocular hypertension patients, keratoconus patients, and subjects undergoing refractive surgeries. The potential impact of this project is immense, as the expected data will improve our understanding of corneal biomechanics in relation to the various natural, pathological, and interventional processes, and the technological advance may lead to a new clinical tool that can improve the diagnosis and treatment of keratoconus, the accuracy of tonometry, and the safety and visual outcome of refractive surgery.