目的:探讨准分子激光原位角膜磨镶术(LASIK)后远方对比敏感度的变化。方法:使用美国Optec6500对比敏感度测试仪,对58例112眼接受LASIK治疗的近视患者,按等值球镜分组,低中度近视组:<-6.00D;高度近视组-6.00～-9.00D和超高度近视组>-9.00D。分别于术前、术后1mo和3mo检查空间频率为1.5,3.0,6.0,12.0,18.0周/度(cycle/degree,c/d)的远方对比敏感度,并进行统计学分析。结果:LASIK术后1mo,低中度近视组术眼远方对比敏感度在1.5,3.0及12.0c/d空间频率的下降有统计学意义;高度近视组术眼远方对比敏感度在6.0及18.0c/d空间频率的下降有统计学意义;超高度近视组术眼远方对比敏感度在所有空间频率的下降均有统计学意义。术后3mo,3组对比敏感度在各个空间频率上有明显恢复,接近术前水平。其中在3.0及12.0c/d空间频率的超高度近视组比低中度近视组下降幅度大。在18.0c/d空间频率的超高度近视组比高度近视组下降幅度大。结论:LASIK术后1mo内,近视度数高者,远方对比敏感度下降明显,并随着时间的推移逐渐恢复。

AIM:To evaluate far contrast sensitivity function before and after myopic laser in situ keratomileusis(LASIK).METHODS:With test chart,far contrast sensitivity was measured in randomly selected 58 subjects 112 eyes before,1 month and 3 months after LASIK.The patients were assigned to three different groups according to the mean spherical equivalent.Mean spherical equivalent of low/moderate myopia group was under-6.00D,average(-4.22±1.24)DS,mean spherical equivalent of high myopia group was-6.00--9.00 D,average(-6.98±1.42)DS,and mean spherical equivalent of superhigh myopia group was over-9.00 D,average(-10.88±1.36)DS.The contrast sensitivity was measured at 1.5,3.0,6.0,12.0 and 18.0 cycles per degree(c/d)spatial frequency respectively and comparison was made in them.RESULTS:There was a general reduction in far contrast sensitivity of superhigh myopia in all spatial frequencies at postoperative 1 month compared with the preoperative contrast sensitivity.The group(<6.00D)preoperative and postoperative contrast sensitivity did not differ at 1 month in all spatial frequency.Descendent rates of far contrast sensitivity in superhigh myopia group were larger than that in low/moderate myopia group at 3.0,12.0c/d(P<0.01),and that in superhigh myopia group were larger than that of in high myopia group at 18.0c/d(P<0.01).There were no siginificant difference between three groups three months after LASIK(P>0.05),and far contrast sensitivity was near preoperational level.CONCLUSION:One month after LASIK,the higher myopia has obvious decrease of far contrast sensitivity.

R779.63