目的：采用标准矢量分析法评价准分子激光角膜上皮瓣下磨镶术(epipolis laser in situ keratomileusis， Epi-LASIK)对散光的矫正效果，并探讨其与明视无眩光下对比敏感度函数(contrast sensitivity function， CSF)变化的关系。

方法：选取行Epi-LASIK术矫正近视散光的68眼，近视屈光度为-5.00～-9.00D，散光屈光度为-1.00～-3.00D，术后随访6mo。运用美国国家标准学会推荐的标准矢量分析法评估Epi-LASIK术后1，6mo散光的矫正效果。采用CSV-1000E对比敏感度仪检测手术前后最佳矫正视力下明视无眩光时的CSF。

结果：术后1mo各空间频率(单位为cycles per degree， c/d)的CSF低于术前(P<0.01)，术后6mo时12c/d和18c/d的CSF分别低于术前(P<0.05)，术后1mo时的3c/d，6c/d和12c/d CSF分别低于术后6mo(P<0.05)； 术后1，6mo时的|SIRC|与18c/d的CSF下降呈正相关(r=0.537， 0.674， P<0.01)； 术后1mo的EM为-0.21±0.29，6mo的EM为-0.12±0.31。

结论：Epi-LASIK术后6mo内，中高度近视合并中低度散光患者可出现明视无眩光下高频段CSF的下降，其下降原因可能与手术引起的散光矫正量有关。

AIM: To evaluate the outcome of astigmatism correction after epipolis laser in situ keratomileusis(Epi-LASIK)by standardized vector analysis, and to investigate the relationship between the result of analysis and the change in contrast sensitivity function(CSF).

METHODS: Totally 68 myopic astigmatism eyes treated with Epi-LASIK. The myopic diopter was range from -5.00D to -9.00D, and the astigmatic diopter was range from -1.00D to -3.00D. The following-up period was for 6 months. The outcome of astigmatism correction was evaluated by the standardized vector analysis which was recommended by the American National Standards Institute. The photopic without glare CSF with best spectacle-corrected visual acuity was examined by CSV-1000E.

RESULTS: The CSF of all spatial frequency in 1 month postoperatively were significant lower than that preoperatively(P<0.01). The CSF of spatial frequency 12c/d(cycles per degree)and 18c/d in 6 months postoperatively were significant lower than that preoperatively(P<0.05). The CSF of 3c/d, 6c/d and 12c/d in 1 month were significant lower than that in 6 months postoperatively(P<0.05). The |SIRC|(absolute surgically induced refractive correction)in 1 month, 6 months were positively correlated with the decrease of 18c/d CSF postoperatively(r=0.537, 0.674, P<0.01). The error of magnitude(EM)in 1 month was -0.21±0.29 and -0.12±0.31 in 6 months postoperatively.

CONCLUSION: There was decrease in high spatial frequency contrast sensitivity under photopic without glare of myopic and astigmatic eyes with midrange and high diopter within 6 months after Epi-LASIK. The SIRC might have correlation with the decrease in contrast sensitivity.

国家自然科学基金资助项目(No.11204277)