Study on Normal and Diseased Corneas w/ the DLS Device

透明的角膜位于眼睛前部，不仅作为折射介质将光线聚焦在视网膜上并帮助我们看东西，而且还作为眼睛前部的主要屏障和壁。严重的角膜疾病会导致混浊和失明。角膜疾病和损伤是当今美国眼科诊所就诊的主要原因。这些疾病也是一些最痛苦的眼部疾病。角膜研究的两个重要领域是：1）探索和理解角膜透明度的分子基础，2）分析角膜伤口愈合和炎症的分子本质。 我们开发了一种新的临床设备，以了解发生在透镜中的分子变化，NASA-NEI动态光散射（DLS）设备。实验室研究表明，它在检测白内障发生的最早变化方面具有潜力。对透镜的临床研究也显示了良好的重复测试再现性、拾取微小变化的灵敏度以及非侵入性体内DLS临床系统的安全性。我们在动物中进行了实验室研究，以确定DLS设备是否也可用于研究角膜。我们发现，它在检测正常状态下角膜的各个层/隔室中的分子差异方面确实也是有用的。此外，我们发现，角膜损伤后，如激光屈光手术，化学损伤和刮伤后，DLS可以检测到的变化是不明显的或使用光学设备，如裂隙灯生物显微镜检测。因此，DLS也有望作为一种非侵入性的体内装置，用于研究正常状态和患病状态下的角膜（例如受伤或手术后或遗传性遗传疾病），以及了解角膜透明度的分子基础的研究。 在这个试点项目中，我们将研究年轻人和老年人（志愿者）的正常角膜以及混浊、不透明的角膜，并确定角膜使用设备的安全性和可重复性。在初步测试中，确定目前用于研究白内障的DLS设备不适合角膜。这是因为角膜和透镜之间的厚度差异（人角膜为0.5 mm，人透镜为3-4 mm），因此氦氖光束的入射角与APD光检测器的角度不正确。因此，需要制造一种新的NASA-NEI角膜DLS装置，该装置已接近完成。

The transparent cornea, located in the front of the eye, acts not only as a refracting medium to focus light on the retina and help us see, but also serves as the main barrier and wall in the front of the eye. Serious disease of the cornea leads to opacification and blindness. Corneal diseases and injuries are the leading reason for visits to eye care clinics in the U.S. today. These diseases are also some of the most painful eye disorders. Two important areas for research on the cornea are: 1) to explore and understand the molecular basis of corneal transparency, and 2) to analyse the molecular nature of corneal wound healing and inflammation. We have developed a new clinical device to understand molecular changes that occur in the lens, the NASA-NEI Dynamic Light Scattering (DLS) device. Laboratory studies have shown its potential in the detection of the earliest changes occuring in cataracts. Clinical studies on the lens have also shown good test-retest reproducibility, sensitivity to pick up small changes, and safety of the non-invasive, in vivo DLS clinical system. We conducted laboratory studies in animals to determine if the DLS device is also useful to study the cornea. We found that it is also indeed useful in detecting molecular differences in various layers/compartments of the cornea in the normal state. In addition, we found that after corneal injury such as after laser photorefractive surgery, chemical injury and scraping, the DLS could detect changes which are not apparent or detectable using optical devices such as the slit lamp biomicroscope. Hence, the DLS also holds promise as a non-invasive, in vivo device to study the cornea in the normal state as well as in diseased states (such as after injury or surgery or in inherited genetic diseases), and in studies to understand the molecular basis of corneal transparency. In this pilot project, we will study the normal cornea in young and older persons (volunteers) as well as cloudy, opaque corneas, as well as determine the safety and reproducibility of the device for corneal use. In preliminary testing, it was determined that the current DLS device used to study cataracts is not properly suited for the cornea. This is because of the difference in thickness between the cornea and the lens (0.5 mm in the human cornea versus 3-4 mmm in the human lens), so that the angle of entry of the Helium Neon Light beam versus the angle of the APD light detector is not correct. Hence a new NASA-NEI DLS device for the cornea needed to be made and is nearing completion.