基于个体化人眼波前像差的非球面人工晶体的定制相关实验研究

The technique of cataract surgery has undergone rapid technologic advances，and intraocular lenses (IOL) materials and designs have improved significantly。Today, the goal of cataract surgery has moved beyond the achievement of good visual acuity。In addition, as wavefront aberration technique has advanced, customizing IOL selection is no longer optional; it is now essential to the practice of refractive cataract surgery。Our previous research had found that larger discrete degree of corneal spherical aberration in cataract surgery crowd and be associated with pupil diameter。Additionally, the amount of spherical aberration correction evaluated on the basis of preoperative anterior corneal spherical aberration was not sufficient, because of the presence of surgically- induced corneal spherical aberrations and posterior corneal spherical aberrations。The goal of this subject was to demonstrate a method of how to calculate aspheric IOLs with a customized asphericity and how to apply this strategy to clinical examples in which the biometric data of the cornea (front and back surface)。This subject intends to establish the cornea model, to determine the distribution and character of higher-order corneal and ocular aberrations。Aspheric IOLs were tested using an optical bench system consisting of a model eye, a high-resolution Hartmann-Shack wavefront sensor, and an image capturing device, to clarify influence of wavefront aberration of single zernike modes on optical quality and theoretical study of wavefront conversion and evaluation of visual function and to customize optimization with the best aspheric IOLs in cataract surgery based on individual eye's wavefront aberrations。

随着白内障手术技术的不断提高和人工晶体的设计及材料的日趋完善，人们逐渐开始关注术后的视觉质量。白内障手术已纳入屈光手术的范畴，也是目前眼科最活跃的研究热点之一。在前期研究中，我们发现白内障手术人群中角膜的球面像差离散程度较大以及受瞳孔大小的明显影响，并在预实验中观察到仅定量评价角膜前表面球面像差是不够的。非球面人工晶体能否根据不同个体的角膜波前像差做到真正的个体化植入呢？目前国内外未见相关报道。本课题拟结合人眼的角膜和全眼波前像差特性和分布规律，整合角膜前、后表面的波前像差，建立符合人眼的解剖结构和光学特性的角膜模型，以及在此基础上，建立个性化的模拟人眼的人工晶体波前像差光路实验系统。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，为探索基于个体化人眼波前像差的非球面人工晶体定制和优化提供理论和技术基础。

本课题拟结合人眼的角膜和全眼的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，在此基础上，建立个性化的模拟人眼的人工晶体波前像差离体光路实验系统。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，为探索基于个体化人眼波前像差的非球面人工晶体定制和优化提供理论和技术基础。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，依据我国人眼的解剖结构和光学相关特性，实验室建立Hartmann-Shack人工晶体波前像差光路系统。研究表明：(1) 角膜前表面Q30为-0.27 ± 0.08，角膜后表面Q30为0.04 ± 0.03，呈正态分布。角膜前表面及全角膜球差分别为0.251 ± 0.073μm和0.212 ±0.084μm，72.5%的眼数在0.15～0.30μm之间。晶状体核密度与球差及平均调制传递函数呈负相关；(2) 不同角膜切口的超声乳化白内障吸除手术前后角膜后表面球面像差具有差异，以及术后角膜后表面的形态学构型发生显著的变化。术中可能会引入新的高阶像差,术后留一定的正的全眼球面像差可提高视觉质量。(3)倾斜角与Coma-like像差之间呈正相关,偏心0-±0.4mm区间三种人工晶体pMTF值有显著差异。应用Zemax软件优化设计个体化非球面人工晶体的光学结构，能够减小人眼的高阶像差，较明显地提高人眼的视觉质量。