波前引导LASIK术后对比敏感度变化

Contrast sensitivity change after wavefront-guided laser in situ keratomileusis

目的探讨波前引导准分子激光原位角膜磨镶术(LASIK)术后对比敏感度的变化。方法采用随机双盲前瞻性对照研究,将50例(100眼)拟行LASIK的患者随机分为波前引导组和传统组,分别检查术前,术后10d,1、3、6个月明光(250lux)、暗光(1lux)及眩光(75lux)下的对比敏感度。结果术前不同状态下对比敏感度两组间差异均无统计学意义(P>0.05),但眩光状态下的对比敏感度低于非眩光状态。术后不同时间传统组在所有状态下的所有频率比术前均提高(P<0.05);而引导组只在术后3个月和6个月的部分频率比术前提高(P<0.05)。术后6个月明光、暗光和暗光+眩光下18c/d的log值增加倍率传统组高于引导组。结论波前引导LASIK术后对比敏感度无明显下降,但提高程度不如传统LASIK。两种手术均能提高眩光状态下高频段对比敏感度。

Objective Many studies showed that contrast sensitivity functions （CSFs） is reduced after laser in situ keratomileusis （LASIK） ,however,no report is found about the CSFs after wavefront-guided LASIK . The aim of our study was to evaluate the changes of CSFs after wavefront-guided LASIK. Methods A prospective, randomized, double-masked and controlled study comprised 100 eyes of 50 young patients who attempted LASIK were curried out. The patients were divided into standard ablation group and wavefront-guided ablation group randomly. Preoperative and postoperative examination included contrast sensitivity under photopic （250 lux） and scotopic （ 1 lux） conditions with or without glare （75 lux）. Results There was no significant difference in CSFs under photopic and scotopic conditions with or without glare before operation between two groups. However,the CSF with glare was lower than that of without glare. The postoperative CSFs under photopic and scotopic conditions both with or without glare were increased significantly in standard ablation group. In wavefront-guided ablation group, the significant increase of CSFs was found only in partial spatial frequency, such as 3 c/d and 6 c/d at 3-month and 6-month of following-up. At 6-month interval ,the increase factors of the log values of CSFs in 18 c/d under photopie or scotopic condition without glare and scotopic condition with glare in standard ablation group were higher than those in wavefront-guided ablation group. Conclusion The increase extent of CSFs following wavefront-guided LASIK are not enough high in comparison with standard LASIK. The CSF in high spatial frequency with glare is increased after both surgeries.