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.

如果努力预测角膜源性的圆锥角膜或屈光手术继发或屈光手术的努力将得到充分准备 角膜生物力学特性的度量可在体内提供，以改善当前的诊断 仅基于结构性评估（即地形和断层图）评估。例如，机械 患者角膜（有或没有地形异常）中发现的弱点（整体或区域） 可能会提醒医生密切监视状况，并可能启动干预措施以逮捕临时 进展。在临床上，仍然缺乏获取空间分辨的生物力学信息的能力。许多 已经提出了方法，但他们经常依靠外力来变形角膜 诱导机械响应。另外，大多数方法并未明确解决 测得的特性上的眼内压（IOP）。 在这个项目中，我们旨在构建一种超声弹性技术，称为眼脉冲弹性图 （OPE），以表征角膜对每个心脏周期IOP循环变化的反应，即 眼脉。基线IOP和眼脉冲放大器都可以在体内测量，将用于 结合从OPE的生物力学测量来得出内在组织生物力学特性 与IOP参数无关。我们的初步研究表明OPE 基于高频超声射频数据分析的技术可以提供应变分辨率 0.05％及以上，使得可靠测量的可靠测量由A的眼脉冲诱导的体内菌株 几个mmhg。 在拟议的研究中，我们将（1）验证OPE技术的角膜机械表征； （2）评估OPE在检测临床相关的角膜僵硬时的灵敏度； （3）定义分布 正常人受试者中OPE衍生的角膜刚度参数的差异及其年龄相关 变化； （4）测试了角膜生物力学特性在圆锥角膜和 开发基于OPE的生物力学指数。前两个目标将调查关系 在OPE测量与传统机械测试的测量以及生理的影响之间 变量和敏感性，以在受控的实验中建立人类眼中的OPE知识 条件（即，在供体眼中），并提供最佳的参数设置和框架以供应和框架 解释体内数据。拟议研究的最后两个目标将带来知识和技术 从板凳到床边，从正常角膜和圆锥角膜中获取体内数据， 建立OPE的临床使用并识别新的，敏感的生物力学指标的第一步 风险。 拟议的研究将解决对角膜的体内体积生物力学评估的需求， 导致临床工具识别和监测生物力学不稳定性或弱化以帮助 诊断和治疗肝病。更广泛地，拟议的研究将影响眼球领域 生物力学，通过生成体内技术和数据，以更好地了解如何涉及生物力学 在眼睛的健康和疾病中。