方法：对264例528眼近视患者施行LASEK手术，随机分为观察组和对照组，分别使用7mm，8mm直径上皮环锯制作角膜上皮瓣。术后1，3，5d比较两组术后角膜刺激症状，术后5d比较两组角膜上皮愈合情况，术后1mo比较两组裸眼视力，术后3mo比较角膜上皮下雾状混浊(haze)程度。

结果：术后1，3，5d观察两组角膜刺激症状、5d观察角膜上皮愈合情况，均明显好于对照组，比较有统计学意义(P<0.05)。术后1mo两组裸眼视力、术后3mo两组haze比较差异无统计学意义(P>0.05)。

结论：使用较小直径上皮环锯的LASEK术后角膜刺激症状轻、上皮愈合和视力恢复较快，总体临床疗效优于使用较大直径上皮环锯。

METHEDS: 264 cases(528 eyes)with myopia were divided into the observed group and the control group randomly, then underwent LASEK surgery using 7mm and 8mm diameters corneal epithelial trephine respectively to make corneal epithelial flap. The comparisons between groups were conducted in terms of corneal irritation, the time of the epithelium healing at 1, 3, 5d, visual recovery at 1mo, and the degree of haze at 3mo.

RESULTS: Corneal irritation at postoperative 1, 3, 5d and the epithelium healing at postoperative 5d in the observed group was much better than that in the control group, there was significant difference(P<0.05). There was no significant difference in visual recovery at 1mo and haze at 3mo between two groups(P>0.05).

CONCLUSION: LASEK with the smaller diameter corneal epithelial trephine is a safe and efficient method to correct myopia than with the bigger diameter with the advantages of having milder irritating symptom, a shorter time of the epithelium healing and the visual recovery.