目的:观察在中高度近视准分子激光上皮下角膜磨镶术（LASEK）中应用丝裂霉素C（MMC）的临床疗效。方法:中高度近视患者166例332眼随机分为观察组和对照组,每组各83例166眼,其中,观察组术中应用0.2g/L的MMC,对照组则不用。术后均随访12mo,观察并比较两组角膜上皮愈合时间、裸眼视力以及角膜haze的发生情况等。结果:观察组角膜上皮修复时间平均为4.05±0.30d,对照组平均为4.22±0.37d,组间比较差异无统计学意义（P＞0.05）；观察组术后12mo时裸眼视力＜0.8者17眼,0.8～者42眼,≥1.0者107眼,各段视力眼数所占百分比与对照组比较差异无统计学意义（P＞0.05）；术前屈光度≤-6.00DS时,观察组术后≤1级或2级haze形成率为18%（3/166眼）,对照组为2.4%（4/166眼）,组间比较差异无统计学意义（P＞0.05）；在-6.00～-8.00DS时,观察组≤1级或2级haze形成率为3.0%（5/166眼）,对照组为10.2%（17/166眼）,组间比较差异有统计学意义（P＜0.05）；≥-8.00DS时,观察组≤1级或2级haze形成率为6.0%（10/166眼）,对照组为17.5%（29/166眼）,组间比较差异有统计学意义（P＜0.05）。结论:在LASEK术中应用0.2g/L的MMC可有效减轻术后haze的发生,且安全性高。

AIM:To observe the effect of mitomycin C(MMC) in middle and high myopic laser subepithelial keratomileusis(LASEK).METHODS:Totally 166 cases (332 eyes) with myopia were randomly divided into observation group with the use of 0.2g/L MMC and control group without the use of MMC ,83 cases (166 eyes) in each group. All patients were followed-up 12 months and the corneal epithelial healing time, the uncorrected visual acuity as well as the occurrence of corneal haze after surgery were observed.RESULTS:The corneal epithelial healing timewas 4.05±0.30 days in the observation group and 4.22±0.37 days in the control group, there was no significant difference between the two groups (P＞0.05). In postoperative 12 months, there were 17 eyes whose uncorrected visual acuity were ＜0.8, 42 eyes were 0.8-1.0 and 107 eyes were ≥1.0, the percent in each section of the two groups had no significant difference between groups (P＞0.05). The incidence of haze ≤1 or 2 grade was 1.8% (3/166 eyes) in observation group and 2.4% (4/166 eyes) in control group with the preoperation diopter was≤-6.00DS, there was no significant difference between the two groups (P＞0.05). While the preoperative diopter was -6.00--8.00DS, the haze rate was 3.0% (5/166 eyes) in observation group and 10.2% (17/166 eyes) in control group, there was significant difference between groups (P＜0.05). When the preoperative diopter was ≥-8.00DS, the haze rate was 6.0% (10/166 eyes) in observation group and 17.5% (29/166 eyes) in control group, there was significant difference between groups (P＜0.05). CONCLUSION:Application of MMC in LASEK can reduce the incidence of postoperative haze effectively with high safety.