Guiding the Treatment of Anterior Eye Disease with Optical Coherence Tomography

项目摘要 光学相干断层扫描（OCT）是一种截面和三维（3-D）成像技术， 非常精细的空间分辨率（5 m）。该项目开发了高精度测量所需的方法和软件， 光学相干断层扫描测量眼睛，以指导眼睛前部的植入、激光和移植手术。在 建议继续该项目，新一代的OCT，具有非常高的速度（约10倍 速度比以前更快，在短短的2/1000秒内拍摄图像）和扩展的范围将使新的 要准确地进行测量的类型。具体目标如下： (1)开发超高速OCT硬件和软件，用于测量前部光学表面 眼睛固有的眼球运动有效地限制了商业OCT对角膜形状的测量。 克服了几种方法，包括超高速OCT在500 kHz，双光束OCT， 同时捕获角膜和透镜的形状，同时捕获Placido环 视频角膜摄影和运动校正软件。目标是提供可靠的前端测量， 角膜和晶状体透镜的后表面。 (2)开发基于OCT的人工透镜屈光度公式。目前，外科医生缺乏一种准确的方法， 为既往接受过激光视力矫正的白内障患者计算精确的眼内透镜（IOL）屈光度。 这些患者在白内障手术后可能会留下近视或远视。基于OCT的IOL配方，使用 前角膜屈光力和后角膜屈光力的测量可以为外科医生提供更精确的信息， 会显著改善视力基于OCT的IOL配方将在临床试验中进行测试。 (3)研制OCT引导的准分子激光表面烧蚀技术。准分子激光可以去除混浊层 从角膜的前面和正确的扭曲形状由于圆锥角膜或移植手术。我们有 开发了基于3-D OCT的计划，以最佳方式消除因角膜瘢痕和基质 营养不良这种方法将在更大规模的临床试验中进行测试。我们将通过增加三维OCT来改进该方法 测量角膜形状（地形图），以计划任何形状失真的矫正。 (4)目的：研究OCT引导下激光辅助前、后板层角膜移植术。大多数角膜 疾病仅涉及角膜的内层或外层。因此，部分厚度移植可以治疗这些 疾病，同时避免全层移植的并发症（排斥，不规则的伤口形状， 等等）。然而，人工剥离角膜层在技术上是困难的，并且手术后的视力受到以下因素的限制： 粗糙的界面。我们已经开发了OCT方法来指导供体和宿主的成形和平滑 角膜与准分子激光的组合，以创建光滑的界面和飞秒激光，以创建 榫槽边缘配合。这些技术的试点临床试验提出。我们的目标是开发 可靠地改善圆锥角膜、角膜营养不良和深度疤痕患者视力的手术。

PROJECT SUMMARY Optical coherence tomography (OCT) is a cross-sectional and 3-dimensional (3-D) imaging technology with very fine spatial resolution (5 ¿m). This project develops the methods and software needed for high-precision OCT measurements of the eye to guide implant, laser, and transplant surgeries in the front part of the eye. In the proposed continuation of the project, a new generation of OCT that has very high speed (about 10 times faster than before, taking an image in as little as 2/1000 of a second) and extended range will enable new types of measurements to be done accurately. The Specific Aims are as follows: (1) To develop ultrahigh-speed OCT hardware and software for measuring optical surfaces of the anterior eye. Intrinsic eye movements effectively limit measurement of corneal shape by commercial OCT. This will be overcome by several approaches, including ultrahigh-speed OCT at 500 kHz, dual-beam OCT to simultaneously capture the shape of both the cornea and lens, simultaneous capture of Placido-ring videokeratography, and motion correction software. The goal is to provide reliable measurements on front and back surfaces of both the cornea and crystalline lens. (2) To develop an OCT-based intraocular lens power formula. Currently, surgeons lack an accurate way to calculate precise intraocular lens (IOL) power for cataract patients who previously had laser vision correction. These patients may be left near- or far-sighted after cataract surgery. An OCT-based IOL formula, using measurements of both anterior and posterior corneal powers, can give surgeons more precise information that will significantly improve visual outcomes. The OCT-based IOL formula will be tested in a clinical trial. (3) To develop OCT-guided excimer laser surface ablation. The excimer laser can remove cloudy layers from the front of the cornea and correct distorted shape due to keratoconus or transplant surgery. We have developed 3-D OCT-based planning to optimally remove cloudiness due to corneal scars and stromal dystrophies. This method will be tested in a larger clinical trial. We will improve the method by adding 3-D OCT measurement of corneal shape (topography) to plan the correction of any shape distortion. (4) To develop OCT-guided laser-assisted anterior and posterior lamellar keratoplasty. Most corneal diseases involve only the inner or outer layer of the cornea. Thus a partial thickness transplant can treat these diseases while avoiding the complications of full-thickness transplantations (rejection, irregular wound shape, etc). However, manual dissection of corneal layers is technically difficult and vision after surgery is limited by the rough interfaces. We have developed OCT methods to guide the shaping and smoothing of donor and host corneas with a combination of excimer laser to create smooth interfaces and femtosecond laser to create tongue-in-groove edge fits. Pilot clinical trials of these techniques are proposed. The goal is to develop surgeries that reliably improve the vision in patients with keratoconus, corneal dystrophies, and deep scars.