角膜地形图对准分子激光屈光性角膜手术后散光变化的判断作用

The prediction of surgically refractive astigmatism changes after refractive surgery from corneal topography

目的探讨准分子激光屈光性角膜手术前后角膜地形图△ＳｉｍＫ变化值在散光度数变化判断中的作用。方法 对近视度为－１． ５０～－２４．００Ｄ，散光度数－０． ７５～－５．５０ Ｄ的患者 ８９例 １５０眼行准分子激光屈光性角膜切削术（ＰＲＫ）或准分子激光原位角膜磨削术（ＬＡＳＩＫ），观察６个月以上。经计算机得出角膜曲率△ＳｉｍＫ变化值 Ｘ与临床散光度数变化值Ｙ的散点图及相关系数ｒ值。结果手术前后Ｘ与Ｙ的关系：Ｙ＝１．４５３６Ｘ＋０．５７３４，ｒ＝０．７２１２，Ｐ＜０．００１。结论准分子激光手术前后角膜地形图△ＳｉｍＫ变化值与临床散光度数变化有高度相关性，对判断术后散光度数变化有重要的意义。

Objective To assess the role of corneal topography in predicting the refractive astigmatism power after refractive surgery. Methods 150 eyes (89 cases ) of myopia astigmatism (> 0. 75D ) were treated with photorefractive keratectomy(PRK) or laser in situ keratomileusis (LASIK), and were followed up for more than 6 months. Preoperative and postoperative A SlinK were measured by corneal topography. The relationship between the △ SimK reduction of corneal topography and the clinical refractive astigmatism reduction from preoperative stage to 6 months or more postoperative stage was evaluated by regression analysis. Results The mean postoperative A SlinK reduction was 0.58±0.39D, and the mean postoperative clinical refractive astigmatism reduction was 1. 415±0.78D. There was significant correlation between the A SlinK reduction of corneal topography (X) and clinical refractive astigmatism reduction (Y): Y=1. 4536X+0. 5734, r=0. 7212,P<0.001. Conclusion There was significant correlation between corneal refractive change (△SimK reduction) and clinical refractive astigmatism change. These results suggest that Corneal power(ASimK) measured by corneal topography may be an essential predictor of surgically refractive astigmatism changes.