Epi-LASIK术后视觉质量分析

An analysis of visual quality after Epi-LASIK

目的:上皮瓣的机械法激光上皮下角膜磨镶术(Epi-LASIK)治疗高度近视安全有效,但仍有部分患者术后视觉质量下降。文中研究Epi-LASIK术后视觉质量下降患眼的高阶像差特点及其与某些因素的相关性,分析术后患眼出现眩光、雾视以及单眼复视的原因。方法:选择2007年7月至2008年8月行Epi-LASIK手术治疗近视的患者,术后3月行视觉质量评分,选取其中评分低于80分,并有明显症状的患者27例34眼,其中夜间眩光者20例25眼,雾视者5例7眼,单眼复视者2例2眼。并选取无症状患者22例42眼作为对照组。采用iTrace视觉功能分析仪测量6mm瞳孔直径下的波前像差值及调制传递函数值。结果:Epi-LASIK术后有症状各组与无症状组在暗视瞳孔直径下的全眼高阶像差存在显著差异。空间频率为15cyc/deg时调制传递函数值雾视组及单眼复视组均较无症状组低(P<0.05)。有症状各组的偏中心值均较无症状组高,且夜间眩光组及单眼复视组与无症状组之间比较有显著差异(P<0.05)。偏中心切削与术后全眼散光、高阶像差、彗差、球差、三叶草差有相关性(P<0.05)。切削直径与眼轴长度及患者术前的屈光度负相关,与患者术后的高阶像差、球差、彗差负相关。结论:Epi-LASIK术后视觉质量下降症状与术后高阶像差较高有关。影响高阶像差的因素主要有偏中心切削值和切削直径。

Objective： Epi-LASIK appeared to be effective and safe in the treatment of high myopia,but some patients complain about visual symptoms postoperation.The purpose of this study was to evaluate the high order aberrations（HOAs） of the vision-decreased eyes treated by Epi-LASIK,and to analyze the causes of postoperative glare,scieropia and monocular diplopia.Methods： We evaluated 76 eyes of 49 patients treated by Epi-LASIK with a questionnaire three months after surgery,and from them selected 34 eyes of 27 patients who scored less than 80 points and complained of postoperative visual symptoms,including glare（25 eyes in 20 patients）,scieropia（7 eyes in 5 patients）and monocular diplopia（2 eyes in 2 patients）.Another 42 symptom-free eyes of 22 patients treated by Epi-LASIK were included in the control group.The root mean square（RMS） of total HOAs,coma and SA were determined with the iTrace Visual Function Analyzer from the central 6.0 mm zone,and the modulation transfer function（MTF） was simulated with the iTrace 3.1 software.Results： Significant differences were found in the RMS of total HOAs,coma and SA between the eyes with visual symptoms and those without,and the values of ablation zone decentration were significantly higher in the former than in the latter（P〈0.05）.Conclusion： Visual symptoms after Epi-LASIK are strongly correlated with higher ocular aberrations.The factors for HOAs mainly include the beam diameter and ablation zone decentration.