Ocular Pulse Elastography

眼脉冲弹性成像

• 批准号: 9353945
• 负责人: JUN LIU
• 金额: $ 12.84万
• 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/9353945
• 关键词: Address; Age; Aging; Biomechanics; Cardiac; Clinic; Clinical; Collagen; Cornea; Custom; Data; Data Analyses; Decision Making; Development; Diagnosis; 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; 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; Ultrasonography; Variant; base; bench to bedside; clinically relevant; crosslink; disease diagnosis; elastography; human subject; improved; in vivo; in vivo imaging; indexing; innovation; insight; radiofrequency; response; simulation; tool; treatment response; trend; volunteer

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 acquire 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.

预测继发于圆锥角膜或屈光手术的角膜扩张风险的努力将大大促进， 角膜生物力学特性的测量可在体内获得以改进当前的诊断 基于结构（即，地形和断层摄影）评价。例如机械 在患者角膜中发现的弱点（整体或局部）（有或没有地形异常） 可以提醒医生密切监测病情，并可能启动干预措施，以阻止扩张， 进展临床上，获取空间分辨生物力学信息的能力仍然缺乏。许多 已经提出了一些方法，但是它们通常依赖于外力来使角膜变形， 引起机械反应。此外，大多数方法没有明确地解决 眼内压（IOP）对测量的性质的影响。 在这个项目中，我们的目标是建立一个超声弹性成像技术，称为眼脉冲弹性成像 (OPE)，以表征角膜对每个心动周期的IOP的周期性变化的响应，即，的 眼脉搏基线IOP和眼脉冲幅度（均为体内可测量）将用于 结合OPE的生物力学测量，推导出内在的组织生物力学特性 与IOP参数无关。我们的初步研究表明， 基于高频超声射频数据分析的技术可以提供 0.05%和更好，使得有可能可靠地测量小的体内应变诱导的眼脉冲的 几毫米汞柱。 在本研究中，我们将（1）验证OPE技术对角膜的力学特性; (2)评价OPE检测临床相关角膜硬化的敏感性;（3）确定OPE的分布 正常人受试者的OPE-derived角膜硬度参数及其年龄相关性的变化 改变;以及（4）测试圆锥角膜中角膜生物力学性质改变的预测， 开发基于OPE-based的圆锥角膜生物力学指标。前两个目标将调查的关系 OPE测量与传统机械测试之间的差异，以及生理学的影响。 变量和敏感性，建立我们的知识，在人类眼睛的OPE在控制实验 条件（即，在供体眼中），并提供最佳的参数设置和框架， 解释体内数据。最后两个目标的拟议研究将带来的知识和技术 从工作台到床边，采集正常角膜和圆锥角膜的体内数据， 建立OPE临床应用和确定新的、敏感的扩张生物力学指标的第一步 风险 拟议的研究将解决角膜的体内体积生物力学评估的需要， 从而产生用于识别和监测生物力学不稳定性或弱化的临床工具， 扩张性疾病的诊断和治疗。更广泛地说，拟议的研究将影响眼科领域， 生物力学，通过生成体内技术和数据，以更好地了解生物力学如何参与 眼睛的健康和疾病。