PRK、LASIK术后角膜地形图的变化对视力恢复的影响

目的：探讨准分子激光角膜切削术（photorefractive keratectomy,PRK)与准分子激光原位角膜磨镶术（laser insitu keratomileusis,LASIK)前后角膜地形图的变化及其与裸眼视力的关系。方法：采用EyeSys2000型角膜地形图系统测量PRK、LASIK术前及术后10天，1、3、6、12及24个月时的角膜地形图并记录同期的视力。结果：角膜地形图显示术后切削形态随着时间延长，趋于规则，Simk的差值和等效值，PRK组和LASIK组术前与术后相比都有显著性差异，术后偏心距离均在1.00mm内，术后裸眼眼力≥0．6，结论：在低、中度近视中，LASIK术后的偏心程度较PRK的稍重，引起裸眼视力偏低。

The comparison between corneal topography and naked vision after PRK and LASIK

Objective:To investigate the changes of corneal topography and its relationship with visual acuity before and after photorefractive keratectomy(PRK)and laser in situ keratomileusis(LASIK).Methods:The EyeSys 2000 corneal topography system was used to measure the corneal topography before PRK or LASIK and after 10 days,1 month,3 months,6 months,12 months,24 months.The relationship between the changes of topography and naked vision at the same period was compared.Results:Keratectomy shape would gradually become regular with the time after surgery.The difference of Simk value difference and Simk equivalent value between before and any period after PRK and LASIK was significant.The eccentricity on corneal topography was within 1 milimeter.Naked vision was 0.6 or more.Conclusion:When myopia degree is lower than -6.00D,the eccentricity on corneal topography after LASIK is more serious than after PRK,and naked vision is also lower.