准分子激光原位角膜磨镶术（LASIK）后球面像差改变的研究

目的探讨准分子激光原位角膜磨镶术（LASIK）术后球面像差的改变及其影响因素。方法采用Orbscan-Ⅱ眼前段分析系统及Zywave波前像差仪对42例（80眼）近视LASIK术前和术后3个月进行检测，分别记录在6．0mm瞳孔直径下的四阶球面像差值、角膜后表面的前凸值、Q值、术中切削光区直径和切削深度，并进行统计学分析。结果LASIK术后四阶球面像差值与术前比较差异有统计学意义（P〈0．01），术前四阶球面像差值0．0923±0．0761，术后3个月四阶球面像差值为0．6067±0．2454，球面像差的变化量和术中切削深度（R=0．01，P〈0．01）、术后角膜后表面的前凸（R=0．06，P〈0．01）、Q值（R=0．36，P〈0．01）有正线性相关，与切削光区直径（R=-0．131，P〈0．01）有显著负相关。结论LASIK术后四阶球面像差呈负线性增大趋势，球面像差的变化值和术中切削深度、术后角膜后表面的前凸及Q值成正线性相关，和切削光区直径成负线性相关。

A correlative analysis about the spherical aberration changes after laser in situ keratomileusis

Objective To evaluate the spherical aberration changes after laser in situ keratomileusis（LASIK） and its correlative factors. Methods We restrosphectively studied the 4th spherical aberrations at 6.0 mm pupil size, the diff value of the posterior corneal surface, asphericity value, the size of ablation zone and the ablation depth in 80 eyes of 42 patients preoperatively and 3 months after LASIK with the Orbscan-Ⅱ system and the Zywave aberrometer. Results The 4th spherical aberration was 0. 0923 ± 0. 0761 properatively and 0.6067 ± 0. 2454 three months after LASIK. The changes of spherical aberration depth was related with the ablation depth （R = 0. 01 ,P 〈0.01 ） ,the diff value of the posterior corneal surface（R = 0. 06, P 〈 0. 01 ）, asphericity value （ R = 0. 36, P 〈 0. 01 ） after LASIK, and had significantly negative correlation with the size of ablation zone. Conclusion The 4th spherical aberration after LASIK was changed and showed some relation with the ablation depth, the diff value of the posterior corneal surface,the asphericity value, and the size of ablation zone.