Non-contact, THz Sensing of Corneal Hydration

描述（由申请人提供）：本提案的目标是开发一个太赫兹成像系统，以成像和空间映射角膜的水合作用。角膜水合作用目前是用超声测厚法测量的，它是从角膜中央厚度和可用水合作用数据之间的经验关系中得出的。该方案将使用角膜光谱学和反射率数据来改进角膜太赫兹反射率模型。这些模型将通过兔角膜模型和活体角膜模型进行评估。初步数据表明，太赫兹成像可以以0.1%的精度和600微米的空间分辨率测量角膜水化。仿真、模拟模型和动物实验将用于评估该方法的可行性，并验证角膜太赫兹成像识别角膜疾病水合变化特征的能力。太赫兹辐射的优点之一是它的光子能量极低。它是眼睛安全的，工作在10 - 20毫瓦。为了确保人类使用的安全性，我们将评估50 5W下太赫兹光照对兔角膜的影响，并对角膜进行组织学和蛋白质组学分析。一旦我们确认安全性并获得必要的IRB批准，我们将在正常志愿者中进行初步的人类角膜成像试验。在获得正常患者（N = 60）的基线信息后，我们将继续研究DSEK手术前后（N = 20）和LASIK手术前后（N = 20）患者的水合作用。从这些研究中积累的数据将被分析，以评估太赫兹成像监测水合水平作为疾病状态的功能的可行性。1

DESCRIPTION (provided by applicant): The goal of this proposal is to develop a THz imaging system to image and spatially map the hydration of the cornea. Corneal hydration is currently measured using ultrasound pachymetry and is derived from an empiric relationship between central corneal thickness and available hydration data. This proposal will use corneal spectroscopy and reflectance data to improve models of THz reflectivity from the cornea. These models will be evaluated using phantoms and in-vivo rabbit corneas. Preliminary data suggest that THz imaging can measure corneal hydration with 0.1% accuracy and a spatial resolution of 600 um. The simulations and phantom models, and animal studies will be used to evaluate the feasibility of the approach and verify the ability of corneal THz imaging to discern hydration changes characteristic of corneal diseases. One of the advantages of THz radiation is its extremely low photon energy. It is eye safe and operates at 10 - 20 uW. To ensure safety for human use we will evaluate THz illumination on the cornea of rabbits at 50 5W and examine the corneas with histology and proteomic analysis. Once we have confirmed safety and obtained necessary IRB approvals we will conduct initial human corneal imaging trials in normal volunteers. After obtaining baseline information from normal patients (N = 60) we will proceed to study hydration in patients before and after DSEK surgery (N = 20), and before and after LASIK surgery (N = 20). Data accumulated from these studies will be analyzed to assess the feasibility of THz imaging to monitor hydration levels as a function of disease state. 1 PUBLIC HEALTH RELEVANCE: This project will develop a new imaging tool for non-contact, high resolution measurements of corneal hydration. This technology, THz imaging, is a low energy, safe imaging modality that has significant potential advantages over current measurement systems. This proposal develops the mathematical models, animal studies, and preliminary human feasibility testing to evaluate the potential of this new technology to detect, diagnose, and track hydration changes in the cornea as a function of disease. 2