激光原位角膜磨镶手术后不良症状的光学分析

Optical Analysis of Different Visual Symptoms after LASIK Surgery

测量了准分子激光原位角膜磨镶(LASIK)手术后人眼的单色像差。并根据术后症状,将所有数据分类为视物星芒状组、单眼复视组、视物雾状组和参考组。视物星芒状组和视物雾状组的三阶和四阶泽尼克(Zernike)像差的均方根(RMS)值明显大于无症状的参考组。术后有不良症状各组的人眼的调制传递函数(MTF)明显低于参考组的调制传递函数。在明视觉条件下,四阶像差特别是对称性的泽尼克球差,对调制传递函数的影响大;而在暗视觉条件下,三阶像差特别是非对称性的泽尼克彗差对调制传递函数的影响大。四阶以上的高阶像差对各有症状组的调制传递函数曲线有影响,而这些高阶像差对参考组的调制传递函数已无明显影响。像差的均方根值和调制传递函数曲线是研究术后不良症状的较有效光学手段。

Monochromatic aberrations of post-LASIK eyes, which are categorized into starburst group, doublevision group, moisture group and reference group according to their visual syraptoms, are measured. The root-mean-square （RMS） value of the third and the fourth-order aberrations from the starburst group and moisture group are larger than the counterparts from the reference group. The modulation transfer function （MTF） of the first three groups is obviously lower than that of the reference group. It is found that in daytime, the fourth-order aberrations, especially the symmetrical Zernike spherical aberration, have more effects on the modulation transfer function, while the effects of the third-order aberrations, especially the asymmetrical Zernike coma, on MTF are more important at night. Higher-order aberrations above the fourth-order still affect the eyes suffered from visual symptoms, whereas no evident effect on eyes of the reference group is found. RMS and MTF are effective ways to study the visual symptoms after surgery.