Noninvasive ultrasound vibro-elastography for assessing ocular disorders

项目摘要 我们对眼睛生物力学特性的作用，如弹性和粘性的理解是不完整的。 由于目前尚无临床方法对其进行体内临床检测。我们建议开发和完善一个 无创超声振动弹性成像(USVE)测量材料粘弹性能的新技术 眼组织，并使用该技术评估两种疾病，青光眼和乳头水肿。我们最近 完成了R21拨款，评估USVE用于评估青光眼。青光眼是第二大致病原因 失明在美国和全世界都有，唯一可用的治疗方法是降低眼压(IOP)。 我们的初步研究发现青光眼和青光眼患者后巩膜波速有显著差异。 正常的眼睛。在另一个试点项目中，我们评估了USVE在乳头水肿患者中的应用。视乳头肿是视神经 肿胀是由颅内压升高引起的，可导致严重的视力丧失。乳头状肿来自 特发性颅内高压(IIH)通常是双侧对称的，但有时也可能是不对称的。 甚至是单方面的。我们发现IIH患者的后巩膜波速明显高于正常人。 而不是健康受试者。此外，单侧乳头水肿患者的波速明显较高。 患眼与健眼比较。这两种疾病都取决于关节的生物力学。 包括视神经头周围的后巩膜在内的眼组织。然而，他们的立场是相反的。 青光眼中筛板变形向后弯曲和向前弯曲的光谱末端 在乳头肿胀中鞠躬。研究这两种疾病将有助于我们更好地理解眼组织的作用 在疾病风险和发展中的特性，以及眼睛的基本粘弹性特征。在目标1中，我们 将开发和改进用于测量眼睛粘弹性特性的USVE。我们将研究各种波浪模型 并开发先进的粘弹性模型来分析眼组织的弹性和粘性 基于波速频散测量。在目标2中，我们将开发和改进用于评估的USVE 50例正常眼压性青光眼(NTG)--发生在正常眼压下的青光眼--和50例 健康受试者。由于眼的生物力学特性将与眼压有关，因此NTG的招募 患者将允许与眼压匹配的对照组进行比较。在目标3中，我们将为以下目标开发和改进USVE 评估有乳头水肿的患者。我们将从IIH和NIH招募50名乳头水肿患者 将他们与50名年龄和性别匹配的健康对照组进行比较。我们将研究USVE的变化 治疗后基线值和消退后视乳头水肿的测量。成功地完成 该项目将提供有关眼组织生物力学特性在眼部疾病中的作用的基础知识 青光眼和乳头水肿。USVE可能有能力分层青光眼损害的风险和 有发生乳头水肿和视力丧失的倾向，并确定新的治疗靶点。

PROJECT ABSTRACT Our understanding of the role of ocular biomechanical properties, such as elasticity and viscosity, is incomplete as there are no clinical methods for their in vivo clinical measurement. We propose to develop and refine a novel noninvasive ultrasound vibro-elastography (USVE) technique to measure viscoelastic properties of ocular tissues, and use the technique to assess two diseases, glaucoma and papilledema. We recently completed a R21 grant, evaluating USVE for assessing glaucoma. Glaucoma is the second leading cause of blindness in the US and worldwide, and the only available treatment is reduction of intraocular pressure (IOP). Our pilot study found significant differences in wave speed in the posterior sclera between glaucomatous and normal eyes. In another pilot project, we evaluated USVE in papilledema patients. Papilledema is optic nerve swelling, caused by increased intracranial pressure, and can cause significant vision loss. Papilledema from idiopathic intracranial hypertension (IIH) is typically bilateral and symmetric but can sometimes be asymmetric and even unilateral. We found that wave speeds in the posterior sclera of IIH patients were significantly higher than healthy subjects. In addition, wave speeds in patients with unilateral papilledema were significantly higher in affected eyes, compared with unaffected contralateral eyes. Both diseases depend on the biomechanics of ocular tissues including the posterior sclera surrounding the optic nerve head. However, they are on opposite ends of the spectrum where the deformation of the lamina cribrosa is back bowing in glaucoma and forward bowing in papilledema. Studying both diseases will help us to better understand the role of ocular tissue properties in disease risk and development, and the basic viscoelastic characteristics of the eye. In Aim 1, we will develop and refine USVE for measuring ocular viscoelastic properties. We will study various wave models in ocular tissues and develop advanced viscoelastic models to analyze ocular tissue’s elasticity and viscosity based on the wave speed dispersion measurements. In Aim 2, we will develop and refine USVE for assessing 50 patients with normal tension glaucoma (NTG) – glaucoma occurring at normal intraocular pressure – and 50 healthy control subjects. Since ocular biomechanical properties will be related to IOP, recruitment of NTG patients will allow comparison with IOP matched controls. In Aim 3, we will develop and refine USVE for assessing patients with papilledema. We will enroll a large cohort of 50 patients with papilledema from IIH and compare them with 50 age- and gender- matched healthy control subjects. We will study the changes of USVE measurements at baseline and after resolution of papilledema after treatment. Successful accomplishment of this project will provide fundamental knowledge about the role of ocular tissue biomechanical properties in glaucoma and papilledema. USVE may have the ability to stratify the risk of glaucomatous damage and the propensity toward the development of papilledema and vision loss, and identify novel targets for therapy.