Optical Coherence Tomography-Aided Differential Diagnosis and Treatment of Irregular Corneas

项目总结 为了看得更清楚，角膜必须保持近乎完美的清晰度和形状。几种疾病过程可能会扭曲 角膜形状和视力下降。这些包括扩张性/圆锥角膜(基质变薄和隆起)，原发 上皮变形(隐形眼镜引起的翘曲、干眼、上皮基底膜营养不良)，以及 间质改变(疤痕、间质营养不良、手术)。其中一些情况在标准情况下可能看起来很相似 但需要非常不同的治疗方法。因此，该项目的一个目标是使用光学 相干层析成像(OCT)，一种具有微米级分辨率的三维成像技术，以 鉴别不同类型的角膜形状不规则。OCT独特的测量能力 上皮厚度和后部地形将被用来开发新的指标来分期和监测 扩张和原发上皮变形。我们还将改进对角膜基质不规则的治疗。 通过结合OCT规划和地形制导的准分子激光消融，这是最近才成为 我们的总体目标是提高早期发现、鉴别诊断、分期、 使用先进的光学成像和激光技术监测和治疗不规则角膜 实现以下具体目标： (1)开发了一种基于OCT的角膜形状不规则分类评价系统。标准角膜 地形图只能测量角膜前表面，本身不能区分不同的 违规行为的原因。在横断面临床研究中，我们将开发OCT地图的数学分析 对角膜前后地形图、角膜上皮细胞和角膜厚度进行检查，以提高早期发现， 不规则的分类和分期，包括扩张、上皮畸形和间质改变。 (2)建立更灵敏的检测圆锥角膜进展的OCT指标。标准前路 最大角膜屈光度等地形参数的重复性和检测灵敏度较差 在早期疾病中。我们的初步结果表明，OCT上皮和后部地形测量是 对早期圆锥角膜更敏感，重复性更好。这可以更及时地识别 需要胶原蛋白交联剂来稳定角膜的患者。将测试病情进展的早期检测 在对亚临床圆锥角膜患者的纵向研究中。 (3)发展OCT和地形图引导下的准分子激光治疗性角膜切削术(PTK)。我们 已证明联合OCT计划的跨上皮下PTK可以显著改善患者的视力 角膜有疤痕或不规则。我们建议使用新的可用来进一步改善手术结果 地形图引导准分子激光已被批准用于准分子激光原位角膜磨镶术 眼睛正常，但还没有做过PTK测试。我们计划进行一项OCT和地形的临床试验 引导下PTK适用于角膜疤痕、基质营养不良和其他不规则的患者。

PROJECT SUMMARY To see well, the cornea must maintain near perfect clarity and shape. Several disease processes can distort corneal shape and degrade vision. These include ectasia/keratoconus (stromal thinning and bulging), primary epithelial deformation (contact lens-related warpage, dry eye, epithelial basement membrane dystrophy), and stromal changes (scar, stromal dystrophy, surgery). Some of these conditions can appear similar on standard anterior topography and yet require very different treatments. Therefore a goal of this project is to use optical coherence tomography (OCT), a 3-dimensional imaging technology with micrometer-level resolution, to differentiate between different types of corneal shape irregularities. The unique ability of OCT to measure epithelial thickness and posterior topography will be used to develop new metrics for staging and monitoring of ectasia and primary epithelial deformation. We will also improve the treatment of corneal stromal irregularities by combining OCT planning and topography-guided excimer laser ablation, which has only recently become available in the U.S. Our overall goal is to improve the early detection, differential diagnosis, staging, monitoring, and treatment of irregular corneas by using advanced optical imaging and laser technologies to achieve the following Specific Aims: (1) Develop an OCT-based system to classify and evaluate corneal shape irregularities. Standard corneal topography only measures the anterior corneal surface and cannot by itself differentiate between different causes of irregularities. In a cross-sectional clinical study, we will develop mathematical analyses of OCT maps of corneal anterior and posterior topography, epithelium, and pachymetry to improve the early detection, classification, and staging of irregularities including ectasia, epithelial deformations, and stromal changes. (2) Develop OCT metrics for more sensitive detection of keratoconus progression. Standard anterior topographic parameters such as maximum keratometry have poor reproducibility and poor detection sensitivity in early disease. Our preliminary results show that OCT epithelial and posterior topographic measurements are more sensitive to early keratoconus and have better repeatability. This could enable more timely identification of patients who need collagen crosslinking to stabilize the cornea. Early detection of progression will be tested in a longitudinal study of patients with subclinical keratoconus. (3) Develop OCT-and-topography guided phototherapeutic keratectomy (PTK) for irregular corneas. We have demonstrated that transepithelial PTK with OCT planning can significantly improve vision for patients with scarred or irregular corneas. We propose to further improve operative results using the newly available topography-guided excimer laser, which has been approved for laser-assisted in situ keratomileusis (LASIK) in normal eyes but has not yet been tested in PTK. We plan to conduct a clinical trial of OCT-and-topography guided PTK for patients with corneal scars, stromal dystrophies, and other irregularities.