Guiding the Treatment of Anterior Eye Disease with Optical Coherence Tomography

项目总结 光学相干层析成像(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所需的方法和软件 对眼睛进行OCT测量，以指导眼前部的植入、激光和移植手术。在……里面 建议继续项目，新一代OCT具有非常高的速度(约10倍 比以前更快，在短短1000秒内拍摄图像)和扩展范围将实现新的 要准确完成的测量类型。具体目标如下： (1)开发超高速OCT测量前部光学表面的硬件和软件 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。这将是 被几种方法克服，包括500 kHz的超高速OCT、双光束OCT到 同时捕捉角膜和晶状体的形状，同时捕捉Placido环 视频摄影和运动校正软件。目标是提供可靠的正面和外部测量 角膜和晶状体的背面。 (2)建立基于OCT的人工晶状体屈光度计算公式。目前，外科医生缺乏一种准确的方法来 为既往接受激光视力矫正的白内障患者计算精确的人工晶状体(IOL)度数。 这些患者可能在白内障手术后留下近视或远视。基于OCT的IOL公式，使用 测量角膜前后屈光度，可以为外科医生提供更准确的信息 将显著改善视觉效果。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浑浊的层。 矫正因圆锥角膜或移植手术而变形的形状。我们有 开发了基于OCT的3-D计划，以最佳方式消除角膜疤痕和基质造成的混浊 营养不良。这种方法将在一项更大的临床试验中进行测试。我们将通过添加3D OCT来改进方法 测量角膜形状(地形图)以计划矫正任何形状扭曲。 (4)开展OCT引导下的前后板层角膜移植。最大角膜 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 同时避免全层移植的并发症(排斥反应、创面形状不规则、 等)。然而，人工剥离角膜层在技术上是困难的，术后视力受到以下因素的限制 粗糙的界面。我们开发了OCT方法来指导供体和宿主的成形和平滑 用准分子激光和飞秒激光相结合的方式创造出光滑的角膜界面 凹槽舌形边缘贴合。建议对这些技术进行试点临床试验。我们的目标是发展 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。

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.