准分子激光原位角膜磨镶术治疗近视后眼高阶像差变化的研究

目的探讨光学区大小对准分子激光原位角膜磨镶术（LASIK）治疗近视后眼高阶像差的影响。方法将接受LASIK治疗的近视者236例（461只眼）分为高、中、低度近视组,每组根据激光切削光学区直径不同（5．75、6．00、6．25和6．50mm）分为Ⅰ～Ⅳ亚组。术前和术后6个月用波阵面像差仪测量眼的像差。用方差分析和q检验分析手术前后各组内不同亚组间在瞳孔直径为4．00、5．00、6．00mm时眼总高阶像差、水平彗差、垂直彗差和球差的差异。结果术前各组内不同亚组间眼高阶像差差异无统计学意义（P〉0．05）。术后6个月,各组内不同亚组间眼总高阶像差和球差差异有统计学意义（P〈0．05）,较大光学区亚组低于较小光学区亚组。高度近视组在不同瞳孔直径时差异均有统计学意义（P〈0．05）,低度近视组在瞳孔直径为6．00mm时差异有统计学意义（P〈0．05）;瞳孔直径为6．00mm时,高度近视组各亚组间差异均有统计学意义（P〈0．05）,低度近视组在Ⅰ、Ⅳ亚组间差异有统计学意义（P〈0．05）。各组内不同亚组间水平彗差和垂直彗差差异均无统计学意义（P〉0．05）。结论光学区大小影响LASIK治疗近视后眼总高阶像差和球差,较大光学区组低于较小光学区组,在治疗高度近视时影响更加明显。

Influence of diameter of optical zone ablation on LASIK-induced higher order optical aberrations in myopia

OBJECTIVE: To analyze the effects of optical zone ablation diameter on LASIK-induced higher order optical aberrations in myopia. METHODS: Four hundred and sixty-one eyes of 236 patients treated with LASIK for myopia were divided into high, moderate and low myopia group according to preoperative spherical equivalent diopter. In each group, eyes were divided into four subgroups according to optic zone ablation diameter. Before and after surgery 6 months, monochromatic wavefront aberrations of each eye were objectively measured using WASCA Analyzer Aberrometer. F test and q test were used to analyze the difference of total high order, horizontal coma, vertical coma, and spherical aberrations among four subgroups in each group at 4, 5, and 6 mm pupil size. RESULTS: Before surgery no significant difference of higher order aberrations among four subgroups was found. After surgery, there was significant difference of total high order, and spherical aberrations among four subgroups. Total high order, and spherical aberrations in larger optical zone ablation diameter subgroup were significantly lower than that in smaller one. The difference was significant at 4, 5, and 6 mm pupil size in high myopia group, and 6 mm pupil size in low myopia group. At 6 mm pupil size, the difference was significant between each subgroup in high myopia group and subgroup I and subgroup IV in low myopia group. There was no significant difference of horizontal coma, and vertical coma aberrations among four subgroups. CONCLUSIONS: Optical zone ablation diameter has influence on LASIK-induced higher order optical aberrations. Larger optical zone can decrease total higher order and spherical aberrations after LASIK. The effects are more significant in high myopia group than in low myopia group.