Guiding the Treatment of Anterior Eye Disease with Optical Coherence Tomography

项目概要 光学相干断层扫描 (OCT) 是一种横截面 3 维 (3-D) 成像技术， 非常精细的空间分辨率（5 µm）。该项目开发高精度所需的方法和软件 眼睛的 OCT 测量可指导眼睛前部的植入、激光和移植手术。在 该项目的拟议延续是新一代OCT，具有非常高的速度（大约是其10倍） 比以前更快，拍摄图像只需 2/1000 秒）和扩展范围将启用新的 准确完成的测量类型。具体目标如下： （1）开发用于测量前牙光学表面的超高速OCT硬件和软件 眼睛。固有眼球运动有效限制了商业 OCT 对角膜形状的测量。这将是 通过多种方法克服这一问题，包括 500 kHz 的超高速 OCT、双光束 OCT 同时捕捉角膜和晶状体的形状，同时捕捉普拉西多环 视频角膜摄影术和运动校正软件。目标是提供可靠的正面和侧面测量 角膜和晶状体的后表面。 (2)开发基于OCT的人工晶状体度数公式。目前，外科医生缺乏准确的方法 为之前接受过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。 这些患者在白内障手术后可能会出现近视或远视。基于 OCT 的 IOL 公式，使用 角膜前部和后部屈光力的测量可以为外科医生提供更精确的信息 将显着改善视觉效果。基于 OCT 的 IOL 公式将在临床试验中进行测试。 (3)发展OCT引导的准分子激光表面烧蚀。准分子激光可以去除浑浊层 从角膜前面进行矫正，并矫正由于圆锥角膜或移植手术而导致的扭曲形状。我们有 开发了基于 3D OCT 的规划，以最佳方式消除由于角膜疤痕和基质造成的混浊 营养不良。该方法将在更大规模的临床试验中进行测试。我们将通过添加 3-D OCT 来改进该方法 测量角膜形状（地形）以计划矫正任何形状扭曲。 (4)开展OCT引导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、伤口形状不规则、 等）。然而，手动解剖角膜层在技术上存在困难，并且术后视力受到以下因素的限制： 粗糙的接口。我们开发了 OCT 方法来指导供体和宿主的塑形和平滑 结合准分子激光创建平滑界面和飞秒激光创建角膜 榫槽边缘配合。建议对这些技术进行试点临床试验。目标是发展 能够可靠地改善圆锥角膜、角膜营养不良和深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.