University of Houston, Department of Biomedical Engineering, Houston, Texas, United States.
Pontificia Universidad Católica del Perú, Department of Engineering, Lima, Perú.
J Biomed Opt. 2024 Jan;29(1):016002. doi: 10.1117/1.JBO.29.1.016002. Epub 2024 Jan 13.
The biomechanical impact of refractive surgery has long been an area of investigation. Changes to the cornea structure cause alterations to its mechanical integrity, but few studies have examined its specific mechanical impact.
To quantify how the biomechanical properties of the cornea are altered by laser assisted keratomileusis (LASIK) using optical coherence elastography (OCE) in porcine corneas.
Three OCE techniques, wave-based air-coupled ultrasound (ACUS) OCE, heartbeat (Hb) OCE, and compression OCE were used to measure the mechanical properties of paired porcine corneas, where one eye of the pair was left untreated, and the fellow eye underwent LASIK. Changes in stiffness as a function of intraocular pressure (IOP) before and after LASIK were measured using each technique.
ACUS-OCE showed that corneal stiffness changed as a function of IOP for both the untreated and the treated groups. The elastic wave speed after LASIK was lower than before LASIK. Hb-OCE and compression OCE showed regional changes in corneal strain after LASIK, where the absolute strain difference between the cornea anterior and posterior increased after LASIK.
The results of this study suggest that LASIK may soften the cornea and that these changes are largely localized to the region where the surgery was performed.
屈光手术的生物力学影响一直是研究领域。角膜结构的变化导致其机械完整性发生改变，但很少有研究检查其特定的机械影响。
使用光学相干弹性成像（OCE）在猪角膜中定量评估激光辅助角膜磨镶术（LASIK）对角膜生物力学特性的影响。
使用三种 OCE 技术，基于波的空气耦合超声（ACUS）OCE、心跳（Hb）OCE 和压缩 OCE，测量配对猪眼角膜的机械特性，其中一只眼睛未经处理，而另一只眼睛接受了 LASIK。使用每种技术测量 LASIK 前后角膜硬度随眼压（IOP）的变化。
ACUS-OCE 表明，未经处理和处理组的角膜硬度均随 IOP 而变化。LASIK 后的弹性波速度低于 LASIK 前。Hb-OCE 和压缩 OCE 显示 LASIK 后角膜应变出现区域性变化，LASIK 后角膜前后面之间的绝对应变差增加。
本研究结果表明，LASIK 可能使角膜变软，这些变化主要局限于手术部位。
