基于个体化人眼光学特性的飞秒激光联合准分子激光原位角膜磨镶术的定制相关实验研究

With the continuous upgrading of the technique of corneal refractive surgery and associated equipment, It is becoming the most popular topic in field of corneal refractive surgery that according to individual eye's optical character to implementation authentic customized ablation.Studies have shown that, there is a significant gap between the all kinds of customized ablation postoperative visual quality and the prediction results of the theoretical calculation。Previous research had found that, there is larger discrete degree of spherical aberration in corneal refractive surgery crowd, and each component of wavefront aberration and the corresponding relationship between the visual quality and digital relationship with customized ablation mode need to further study and should be designed to establish the compensation for presbyopia。This topic is simulated using the wavefront reconstruction and geometrical optics theory program to integrated the wavefront aberration of corneal surface, established laser photorefractive keratectomy model what is in accordance with excimer of anatomy structure and optical properties and on this basis to establish the wavefront aberration optical experimental system to simulate the structure of the eye, to elucidate the effects of single and combination of zernike modes on image quality, and the wavefront transformation evaluation and visual function theory, to provide theoretical and experimental basis for designed optical properties of reliable optimization according with femtosecond laser-assisted laser in situ keratomileusis.

随着角膜屈光手术方式的不断发展和相关设备的进一步更新，根据不同个体的人眼光学特性做到真正的个体化切削正成为角膜屈光领域最热点的话题。研究表明，目前进行的各种模式个性化切削的术后视觉质量与术前预测的理论计算结果尚存明显差距。在前期研究中，我们发现适宜角膜屈光手术人群中眼球波前像差离散程度较大，波前像差的各组成部分与视觉质量之间的对应关系以及与个性化切削模式之间的数字化对应关系仍有待进一步探索，还应建立补偿日后老视的设计。本课题拟通过波前重构和几何光学理论编制程序将角膜前、后表面波前像差整合，建立符合人眼解剖结构和光学特性的准分子激光角膜切削模型，以及在此基础上，实验室搭建模拟人眼的波前像差光路系统，来阐明单项及组合泽尼克像差对视网膜成像质量的影响规律及波前转换和视觉功能评价理论，为设计最优化的符合个体化人眼光学特性的飞秒激光联合准分子激光原位角膜磨镶术提供可靠的理论和实验基础。

本课题拟结合适宜角膜屈光手术人群的角膜和全眼波前像差特性和分布规律，建立符合人眼解剖结构和光学特性的角膜模型。阐明单项及组合泽尼克像差对成像质量的影响规律，以及波前转换和视觉功能评价理论，为探索符合个体化人眼光学特性的飞秒激光联合准分子激光原位角膜磨镶术提供可靠的理论和实验基础。首次采用多层次(整体，模型眼)和多方法(角膜地形图、波前像差仪、对比敏感度等)相结合的方法，依据适宜准分子激光手术人群的解剖结构和光学相关特性，实验室建立Hartmann-Shack波前像差光路系统。研究表明：(1)适宜准分子激光手术人群的角膜前表面6.0mm瞳孔直径的Q30为-0.19 ± 0.03(范围:-0.58～0.31)，呈正态分布，角膜后表面Q30为0.02 ± 0.03(范围: -0.21～0.26)。RMS3占总高阶像差的62.92％。球差在低、中、高度近视组中分别占59.3%，52.1%和42.5%，彗差则为42.2%，56.4%和62.3%。不同近视组的角膜高阶像差比较显示Coma(3,-1)有统计学差异(P = 0.013)。(2)正常人调节后眼球的调制传递函数在5和10cpd空间频率较调节前显著降低(P = 0.031，P = 0.045)。调节后眼球的波阵面像差图及视网膜视觉质量下降。球镜与Dist to apex（瞳孔最大直径中心与角膜顶点距离）呈负相关性（r =- 0.214, P = 0.002）。（3）运用个性化光学结构角膜模型和Hartmann-Shack波前像差光路系统可以预测和评价角膜屈光手术人群的客观视觉质量。波前引导的飞秒激光联合准分子激光原位角膜磨镶术可能会引入新的高阶像差，保留一定正的全眼球面像差可提高光学质量，不同的波前像差组合和像差补偿对个体化切削模式的角膜屈光手术的视网膜成像质量有更好的优势。