摘要
目的分析近视散光患者行准分子激光原位角膜磨镶术(LASIK)手术前后屈光状态和角膜形态对高阶像差的影响。方法在LASIK术前和术后6个月,分别对患者69例108眼进行角膜地形图和波前像差检查,屈光矫正范围(-1.25^-9.00)D,切削直径为6.0mm或6.5mm。结果LASIK手术前后在6.0mm瞳孔直径下最主要的高阶像差是3阶彗差、4阶球差和三叶草散光,术后总高阶像差的均方根(RMSh)增加1.82倍。术后RMSh变化与近视度的矫正量呈正相关,主要表现为3阶彗差和4阶球差的变化。术后角膜表面不对称指数(SAI)显著增加,RMSh的变化与其增加量呈正相关,特别是3阶彗差。角膜形态术前为不规则型及术后为半环型和中央岛型时SAI增大,高阶像差增大。结论LASIK手术前后的主要高阶像差均为3阶彗差和4阶球差。术后总高阶像差增大,主要表现为慧差增大,可能为角膜表面的不对称性增大引起。
Objective The purpose of this study was to analyze the influence of refractive errors and corneal topography on higher order aberrations in myopic astigmatic patients before and after laser in situ keratomileusis （LASIK）. Methods WaveScan WaveFront System and Tomey Corneal Topography were used to measure wavefront aberrations and corneal topography on 108 eyes of 69 patients with myopic astigmatism at 6.0 mm pupil size before and after（6 months） LASIK. The correction range of LASIK was - 1.25 - - 9.00 diopter and ablation zone was 6.0 mm or 6. 5 mm. Results The main higher order aberrations were the 3rd coma,the 4th spherical aberration and trefoil before and after LASIK under the pupil diameter of 6.0 mm. The root mean square of higher order aberrations（RMSh） increased by 1.82 times after LASIK. The increment of RMSh showed a positive correlation with the change of myopia, demonstrating a major increment in the 3rd coma and the 4th spherical aberration. The Surface Asymmetry Index（SAI） increased significantly after LASIK and had a positive correlation with the increment of RMSh, especially the 3rd coma. SAI increased when corneal topography was irregular shape before LASIK and semicircular and central island shapes after LASIK. RMSh of those shapes was higher than that of the other shapes. Conclusion The main higher order aberrations are the 3rd coma,the 4th spherical aberration and trefoil before and after LASIK. RMSh and the 3rd coma increase after LASIK. The increment of the corneal asymmetry may result in their change.
出处
《眼科研究》
CSCD
北大核心
2008年第6期458-461,共4页
Chinese Ophthalmic Research
