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目的分析LASIK术后角膜曲率计、角膜地形图及高斯光学公式评价角膜屈光力的准确性。方法以临床病史法计算所得的屈光源性K值为评价的基准,对LASIK术后44例(84只眼)角膜屈率计测得的K值、角膜地形图测得的有效屈光力值以及根据裂隙扫描角膜地形图(O rbscan)所测得的角膜前、后曲率半径,用高斯光学公式计算所得的角膜屈光力与之比较,并进行相关与回归分析。结果角膜率计测量的K值较病史法计算值低估(1.35±0.88)D(P<0.001),两者相关系数为0.885;EyeSys角膜地形图有效屈光力较病史法计算值低估(0.91±0.57)D(P<0.001),两者相关系数为0.964;差异均随角膜平面等效球镜度改变量的增加而增大;而高斯光学公式计算值所得较病史法计算值高估(0.31±0.34)D(P<0.001),与病史法计算值相关性最高(r=0.987)。结论以临床病史法计算值为基准,LASIK术后角膜屈率计和角膜地形图的测定值可通过角膜平面等效球镜度的改变量来矫正,在可获得角膜前、后曲率半径的情况下也可通过高斯公式而求得。
Objective To analyze the accuracy of corneal refractive power, corneal topography and Gaussian optical formula after LASIK. Methods Based on the K value of refractive source calculated by the clinical history method, the K values measured by cornea refractometer in 44 cases (84 eyes), the effective refractive power measured by corneal topography, Scan corneal topography (O rbscan) measured before and after the corneal curvature, corneal refractive power calculated by Gaussian optical formula compared with, and correlation and regression analysis. Results The corneal topography showed that the K value was underestimated (1.35 ± 0.88) D (P <0.001) and the correlation coefficient was 0.885. The effective refractive power of EyeSys corneal topography was lower than that of the histopathological method (0.91 ± 0.57) (P <0.001). The correlation coefficient between the two was 0.964. The differences were all increased with the increase of the corneal equivalent spherical power. The calculated values of Gaussian optical formula were higher than the values calculated by the histopathological method (0.31 ± 0.34 ) D (P <0.001), the highest correlation with the calculated value of history (r = 0.987). Conclusions Based on the clinical and histological methods, the measured value of corneal refractometer and corneal topography after LASIK can be corrected by the change of corneal equivalent spherical scope. When the curvature radius before and after the cornea can be obtained The next Gaussian formula can be obtained.