波前引导LASIK术后角膜地形图变化

目的探讨波前引导准分子激光原位角膜磨镶术（laser in situ keratomileusis。LASm）术后角膜前表面地形图的变化。方法比较分析23例（46眼）波前引导LASIK（引导组）和27例（54眼）传统LASIK（传统组）术后不同时期角膜地形图变化。结果2组患者术前角膜平均曲率（K）、角膜散光屈光力（K1—K2）、表面不对称指数（surface asymmetry index,SAI）、表面规则指数（surface regularity index，SRI）均无显著差异（P〉0．05）。2组术后K1—K2减小，SAI明显增加，SRI亦有轻度增加（P〈0．05）。术后6个月引导组与传统组的K、K1—K2、SAI、SRI分别为39．70、0．71、0．15、0．39和39．86、0．85、0．20、0．46。术后6个月传统组SAI高于引导组（P〈0．05）。术后不同时间SRI与术前差值比较．结果显示引导组和传统组均以术后3个月为最高，术后6个月为最低，引导组SRI术后时间变化有统计学意义（P〈0．05）。而引导组与传统组术后不同时间SAI、SRI差值比较差异无统计学意义（P〉0．05）。角膜地形图形态术前引导组与传统组均以不对称领结形为著，分别为50．0％和48．1％．术后不同时间2组均以均匀形为著。但引导组中不规则形所占比例明显高于传统组（P〈0．05）。结论波前引导LASIK术后角膜的规则性和对称性优于传统LASIK，但角膜形态的不规则性明显增加。[眼科新进展2007；27（2）：123-126]

Changes of corneal topography after wavefront-guided laser in situ keratomileusis

Objective To investigate the changes of anterior surface corneal topography after wavefront-guided laser in situ keratomileusis(LASIK).Methods The changes of anterior surface corneal topography were compared between the wavefront-guided ablation group(46 eyes)and standard ablation group(54 eyes)at the different time after surgery.Results There was no significant difference between two groups in average corneal curvature(K),average corneal astigmatism(K1-K2),surface regularity index(SRI),surface asymmetry index(SAI)preoperatively(P>0.05).The values of postoperative SAI and SRI increased significantly while K1-K2 decreased significantly in both groups(P<0.05).At 6 months postoperatively,the value of K,K1-K2,SAI,SRI in the wavefront-guided and standard ablation group was 39.70,0.71,0.15,0.39 and 39.86,0.85,0.20,0.46;The value of SAI in standard ablation group was significantly higher than that in wavefront-guided ablation group(P<0.05).It was the highest at postoperative 3 months and the lowest at postoperative 6 months of the value of SRI in both groups while there was significant difference in wavefront-guided ablation group(P<0.05).There was no significant difference between two groups in the values of SRI and SAI(P>0.05).The form of asymmetry tie was the most frequent type in corneal topography preoperatively,with 50.0% and 48.1% in wavefront-guided and standard ablation group,respectively.However,the regular form was the most frequent type in corneal topography postoperatively,but the percent of the irregular form in wavefront-guided ablation group was higher than that in standard ablation group(P<0.05).Conclusion The asymmetry and regularity of corneal in wavefront-guided ablation group are better than those in standard ablation group,but the percent of the irregular form increases significantly.