矢量法评价Epi-LASIK对散光的矫正效果及其与视觉质量变化的关系

Vector analysis of correction of astigmatism by Epi-LASIK and the relationship between the result of analysis and the change in visual quality

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 relatioship 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 thatpreoperatively（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 I SIRCI （ 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.