眼散光的矢量分析法：一种新型眼散光分析方法的建立及对准分子激光屈光手术后视觉质量下降的预测和补救作用

After excimer laser refractive surgery, the reason and mechanism of reducing visual quality is not clear yet. There do not have effective methods to cope with it. Plenty of evidence shows that it has close relationship between reducing visual quality and astigmatism. However, the detection methods of astigmatism are lack of wholesome and accuracy, and it is inefficient to controlling the reducing visual quality after surgery. Therefore，we are supposed to establish a new, scientific, primary and perfect method to analysis astigmatism. The methods synthesize the optics, ophthalmology, biomechanics and maths. Our methods use vector analysis so as to study the ocular astigmatism and its component which including anterior corneal surface astigmatism, posterior corneal surface astigmatism and lenticular. Using Pentacam HR to confirm the vector analysis result. Furthermore we use astigmatism vector analysis to cope with the reducing visual quality. Our study will provide a new way to analysis astigmatism. Moreover our method is a simple, practical and easy way. Our methods will provide a way to predict the postoperative result, to avoid the mistake during surgery and to remedy the astigmatism after surgery. Our methods are useful to improve safety, effectiveness and prediction after surgery, that will improve quality of surgery and enhance long term of prognosis.

准分子激光屈光手术后视觉质量下降的原因和发生机制不明，尚无较好防治方法。大量证据表明，散光可能与术后视觉质量下降关系密切，但目前应用的散光检测方法缺乏全面性和准确性，不利于术后视觉质量下降控制。我们拟建立一种新型、科学、规范和完善的眼散光分析方法，综合光学、眼视光学、角膜生物力学和数学等多学科交叉知识和技术，运用矢量法对眼散光及各组成部分，包括角膜前、后表面散光和晶状体散光进行完整分析，定量轴向和屈光度，并利用Pentacam HR眼前节分析系统对其可靠性和准确性进行验证。继而将这种眼散光分析方法应用于准分子激光屈光手术前后，观察对术后视觉质量下降的控制和改善作用。本研究将为眼散光的科学、规范和全面分析提供新手段，简单实用、利于普及，为准分子激光屈光手术后视觉质量下降的术前预测、术中规避和术后补救提供方法学的支持，有助于提高手术的安全性、有效性和可预测性，从而改善手术质量，提高远期疗效。

大量证据表明，散光可能与术后视觉质量下降关系密切，但目前常规应用的散光检测方法缺乏全面性和准确性，不利于术后视觉质量下降的控制。本项目组根据经典光学理论进行了创新性的推理论证，利用较先进的眼前节三维分析诊断系统，并联合采用两种不同的矢量分析法，创新性地设计了定量检测角膜厚度非均匀和非正交分布的方法，基本阐明了角膜厚度非均匀和非正交分布的关系，从而创新性的定量检测了角膜后表面散光对角膜前表面散光的补偿作用，即“角膜补偿散光”。根据角膜厚度非均匀和非正交分布的关系，基本阐明了及其对准分子激光术矫正近视性散光效果的影响。根据标准矢量法和屈光力矢量法自主研发了软件，命名为眼散光分析大师OCASAN(OCular AStigmatism ANalyzer)。“角膜补偿散光”可应用于屈光手术前对角膜散光的评估，以及预测术后散光的矫正效果，还可用于预测非手术方法对散光的矫正效果，比如硬性角膜接触镜矫正散光等。OCASAN可应用于眼散光，全角膜散光，角膜前表面散光和角膜后表面散光的检测和分析。