方法：将行EPI-LASIK术的60例120眼按等效屈光度(SE)分为两组：低度近视组(60眼)，中度近视组(60眼)。测量术前和术后1wk； 1，6mo的客观视力、像差、对比敏感度和眩光敏感度并进行比较。

结果：术后两组裸眼视力(UCVA)均优于术前最佳矫正视力(UCVA)(P<0.05)； 两组术后6mo总高阶像差值RMS比较有统计学差异(P<0.05)。两组术前及术后6mo高阶像差值比较均有统计学差异(P<0.05)； 术后1wk； 1mo两组在五个频率上均有统计学差异(P<0.05)； 术后6mo低度近视组恢复至术前水平，中度近视组在高频区(18.0c/d)和术前有统计学差异(P<0.05)； 术后1wk两组在3.0，6.0，12.0，18.0c/d频率上差异均有统计学差异(均P<0.05)，术后1mo两组在12.0，18.0c/d频率上有统计学差异(均P<0.05)，术后6mo两组均恢复至术前水平，比较均无明显差异。

结论：低中度近视EPI-LASEK术后早期的视觉质量较差，中晚期有较好的视觉质量。

METHODS: Sixty cases(120 eyes)undergone EPI-LASIK with equivalent diopter(SE)were divided into two groups: mild myopia group(60 eyes)and moderate myopia group(60 eyes). Objective visual acuity, aberration, contrast sensitivity and glare sensitivity were measured before and 1wk; 1, 6mo after operation, and made comparative analysis.

RESULTS: Postoperative uncorrected visual acuity(UCVA)of two groups were better than that of preoperative(P<0.05). Postoperative 6mo, there were significant differences on total high RMS between two groups(P<0.05). Before operation and 6mo after operation, higher-order aberrations had statistically significant difference between two groups(P<0.05). After 1wk and 1mo, there were statistical significances at the five frequencies between two groups(P<0.05). After 6mo, the mild myopia group returned to preoperative levels, however, moderate myopia group in the high frequency region(18.0c/d)had significant difference with before surgery(P<0.05). 1wk after surgery, there were statistically significant differences on the 3.0, 6.0, 12.0, 18.0c/d frequency in both groups(all P<0.05), 1mo after surgery, there were significant difference at 12.0, 18.0c/d frequencies(all P<0.05), after 6mo, both groups returned to preoperative levels, showed no significant difference.

CONCLUSION: Visual quality is poorer in mild myopia patients than that in moderate myopia at early stage after EPI-LASIK. Better visual quality is observed at mid-late stage.