Ocular Pulse Elastography

眼脉冲弹性成像

• 批准号: 9191364
• 负责人: JUN LIU
• 金额: $ 36.74万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-12-01 至 2020-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9191364
• 关键词: AIDS diagnosis; Address; Age; Aging; Biomechanics; Cardiac; Clinic; Clinical; Collagen; Cornea; Custom; Data; Data Analyses; Decision Making; Development; Diagnosis; Diastolic blood pressure; Disease; Dose; Economic Inflation; Evaluation; Eye; Eye diseases; Frequencies; Functional disorder; Health; Heart Rate; Human; Image; Intervention; Keratoconus; Knowledge; Lead; Maps; Measurable; Measurement; Measures; Mechanics; Methods; Modeling; Monitor; Operative Surgical Procedures; Pathological Dilatation; Patients; Periodicity; Physicians; Physiologic Intraocular Pressure; Physiologic pulse; Physiological; Play; Property; Protocols documentation; Quantitative Evaluations; Regression Analysis; Research; Resolution; Riboflavin; Risk; Role; Science; Secondary to; Solubility; Spatial Distribution; Staging; Structure; Techniques; Testing; Therapeutic; Thick; Tissues; Ultrasonics; Ultrasonography; Variant; base; bench to bedside; clinically relevant; crosslink; disease diagnosis; elastography; human subject; improved; in vivo; in vivo imaging; indexing; innovation; insight; mechanical force; mechanical properties; public health relevance; radiofrequency; response; simulation; tool; translational impact; treatment response; trend; volunteer

 DESCRIPTION (provided by applicant): Ocular Pulse Elastography Efforts to predict corneal ectasia risk secondary to keratoconus or refractive surgery will be greatly facilitated if the measures of corneal biomechanical properties are made available in vivo to improve current diagnoses based on structural (i.e., topographic and tomographic) evaluations alone. For example, mechanical weaknesses (overall or regional) identified in patients' corneas (with or without topographical abnormalities) could alert physicians to closely monitor the condition and potentially initiate interventions to arrest ectatic progression. Clinically, the ability to acquie spatially resolved biomechanical information is still lacking. Many approaches have been proposed, but they often rely on an external force to deform the cornea in order to induce a mechanical response. In addition, most methods do not explicitly address the influence of the intraocular pressure (IOP) on the measured properties. In this project, we aim to build an ultrasound elastographic technique, termed as the ocular pulse elastography (OPE), to characterize the cornea's response to the cyclic variation of IOP at each cardiac cycle, i.e., the ocular pulse. The baseline IOP and ocular pulse amplitude, which are all measurable in vivo, will be used in combination with the biomechanical measures from OPE to derive the intrinsic tissue biomechanical properties that are independent of the IOP parameters. Our preliminary studies have demonstrated that the OPE technique, based on high frequency ultrasound radiofrequency data analysis, can provide a strain resolution of 0.05% and better, making it possible to reliably measure small in vivo strains induced by an ocular pulse of a few mmHg. In the proposed research, we will (1) validate the OPE technique for mechanical characterization of the cornea; (2) evaluate the sensitivity of OPE in detecting clinically relevant corneal stiffening; (3) define the distribution and variance of OPE-derived corneal stiffness parameters in normal human subjects and their age-associated changes; and (4) test the prediction that corneal biomechanical properties are altered in keratoconus and develop OPE-based biomechanical indices for keratoconus. The first two aims will investigate the relationship between OPE measures and those from traditional mechanical testing, as well as the effects of physiological variables and sensitivity, to build our knowledge of OPE in human eyes under controlled experimental conditions (i.e., in donor eyes) and provide optimal parametric settings and framework for acquiring and interpreting in vivo data. The last two aims of the proposed research will bring the knowledge and technique from the bench to the bedside to acquire in vivo data from normal corneas and those with keratoconus, as the first step of establishing OPE's clinical use and identifying new, sensitive biomechanical metrics for ectasia risks. The proposed research will address the need for in vivo volumetric biomechanical evaluation of the cornea, leading to a clinical tool for identifying and monitoring biomechanical instability or weakening to aid the diagnosis and treatment of ectatic disease. More broadly, the proposed research will impact the field of ocular biomechanics, by generating in vivo techniques and data to better understand how biomechanics are involved in the health and disease of the eye.

 描述（由申请人提供）：眼脉冲弹性成像 如果角膜生物力学特性的测量在体内得到极大的利用，以改善当前基于结构（即地形和例如，在患者角膜（有或没有地形异常）中发现机械缺陷（整体或局部）。可以提醒医生密切监测病情，并可能采取干预措施来阻止扩张进展。临床上，仍然缺乏获取空间分辨生物力学信息的能力，但它们通常依赖于外力来使角膜变形。此外，大多数方法没有明确解决眼压（IOP）对测量特性的影响。在这个项目中，我们的目标是建立一种超声弹性成像技术，称为眼脉冲。弹性成像（OPE），用于表征角膜对每个心动周期眼压周期性变化（即眼脉冲）的反应。基线眼压和眼脉冲幅度均可在体内测量，将与生物力学结合使用。我们的初步研究表明，基于高频超声射频数据分析的 OPE 技术可以提供应变分辨率。 0.05% 或更好，使得能够可靠地测量由几毫米汞柱的眼脉冲引起的小体内应变。在拟议的研究中，我们将 (1) 验证用于角膜机械表征的 OPE 技术 (2)。评估 OPE 在检测临床相关角膜硬化方面的敏感性；(3) 定义正常人类受试者中 OPE 衍生的角膜硬度参数的分布和方差及其与年龄相关的变化；以及 (4) 测试角膜硬化的预测；圆锥角膜的生物力学特性发生改变，并开发基于 OPE 的圆锥角膜生物力学指数。前两个目标将研究 OPE 测量值与传统机械测试的测量值之间的关系，以及生理变量和敏感性的影响，以建立我们的知识。在受控实验条件下（即在供体眼睛中）进行人眼 OPE 并提供用于获取和解释体内数据的最佳参数设置和框架。拟议研究的最后两个目标将从该技术中带来知识和技术。作为建立 OPE 临床应用和确定新的、敏感的角膜扩张风险生物力学指标的第一步，该研究将满足体内体积生物力学评估的需求。更广泛地说，这项研究将影响眼部领域，从而开发出一种用于识别和监测生物力学不稳定或减弱的临床工具，以帮助诊断和治疗扩张性疾病。生物力学，通过生成体内技术和数据来更好地了解生物力学如何参与眼睛的健康和疾病。