Guiding the Treatment of Anterior Eye Disease with Optical Coherence Tomography

描述(由申请人提供)： 光学相干层析成像(OCT)是一种具有很高空间分辨率(5.5m)的断层三维成像技术。该项目开发了高精度OCT测量眼睛所需的方法和软件，以指导眼睛前部的植入、激光和移植手术。在该项目的拟议延续中，新一代OCT具有非常高的速度(大约比以前快10倍，在1000秒内拍摄图像)和扩展的范围，将使新类型的测量能够准确完成。具体目标如下：(1)开发用于测量前眼光学表面的超高速OCT硬件和软件。固有的眼球运动有效地限制了商业OCT对角膜形状的测量。这将通过几种方法来克服，包括500 kHz的超高速OCT，同时捕捉角膜和晶状体形状的双光束OCT，同时捕捉Placido-Ring视频角膜照相术，以及运动校正软件。其目标是提供可靠的角膜和晶状体前后表面的测量。(2)建立基于OCT的人工晶状体屈光度计算公式。目前，外科医生缺乏一种精确的方法来计算以前接受过激光视力矫正的白内障患者的人工晶状体(IOL)度数。这些患者可能在白内障手术后留下近视或远视。一种基于OCT的人工晶状体公式，使用前后角膜屈光度的测量，可以为外科医生提供更准确的信息，从而显著改善视力结果。基于OCT的人工晶状体配方将在临床试验中进行测试。(3)开展OCT引导下准分子激光表面消融。准分子激光可以去除角膜前面的混浊层，并纠正圆锥角膜或移植手术造成的扭曲形状。我们已经开发了基于三维OCT的计划，以最佳地去除由于角膜疤痕和基质营养不良引起的混浊。这种方法将在一项更大的临床试验中进行测试。我们将通过增加角膜形状(地形图)的三维OCT测量来改进方法，以计划纠正任何形状扭曲。(4)开展OCT引导下的前后板层角膜移植。大多数角膜疾病只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，同时避免全厚度移植的并发症(排斥反应、不规则的伤口形状等)。然而，人工剥离角膜层在技术上是困难的，而且手术后视力受到粗糙界面的限制。我们开发了OCT方法来指导供体和宿主角膜的整形和平整，结合使用准分子激光来创建平滑的界面，并使用飞秒激光来创建槽舌边缘配合。建议对这些技术进行试点临床试验。其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的视力的手术。 公共卫生相关性： 光学相干层析成像(OCT)以比传统仪器更高的分辨率和速度对角膜形状和厚度进行非接触式测绘。该项目将开发下一代超高速OCT仪器，并使用它们来准确计算人工晶状体的度数，并改善以前有激光视力矫正的眼睛的白内障手术结果。这些仪器还将为提高激光矫正混浊或不规则角膜和激光辅助角膜移植的精确度、安全性和有效性提供数据。

DESCRIPTION (provided by applicant): Optical coherence tomography (OCT) is a cross-sectional and 3-dimensional (3-D) imaging technology with very fine spatial resolution (5 5m). 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. PUBLIC HEALTH RELEVANCE: Optical coherence tomography (OCT) performs noncontact mapping of corneal shape and thickness with higher resolution and speed than conventional instruments. This project will develop the next generation of ultrahigh-speed OCT instruments and use them to accurately calculate intraocular lens power and improve outcomes of cataract surgery in eyes with previous laser vision correction. These instruments will also provide data to improve the precision, safety, and effectiveness in laser correction of cloudy or irregular corneas and laser-assisted corneal transplantation.