两种方法对LASIK手术前后角膜厚度测量的对比研究

Study on Corneal thickness measurements with the Orbscan-Ⅱ Topography and ultrasonic pachymetry before and after LASIK

目的研究Orbscan-Ⅱ角膜地形图仪对准分子激光原位角膜磨镶术(LASIK)手术前、后角膜厚度测量效果。方法应用Obscan-Ⅱ角膜地形图仪和A超角膜测厚仪分别测量150例(300只眼)LASIK手术前及术后6个月患者的角膜厚度,进行分析比较。结果术前A超角膜测厚仪测量结果平均为(545.43±29.079)μm,Orbscan-II测量结果平均为(535.17±32.352)μm,Orbscan-II比A超角膜测厚仪测量的中央角膜厚度薄(10.27±15.188)μm;术后6个月A超角膜测厚仪测量结果平均为(457.64±32.30)μm,Orbscan-II测量结果平均为(417.06±46.422)μm,Orbscan-II比A超角膜测厚仪测量的中央角膜厚度薄(51.15±18.4)μm。两参数检验有统计学意义,两种方法有高度相关性。结论Orbscan-II测量所得的角膜厚度值可以作为LASIK手术前后很好的参考依据。

Objective To investigate the difference on corneal thickness measurements using Orbscan-ⅡSystem and ultrasonic pachymetry before and after LASIK in myopic patients.Methods Orbscan-ⅡSystem and A-scan ultrasonography were used to measure the corneal thickness pre-and post-operative in 300 eyes of 150 cases that underwent myopic LASIK.The differences were evaluated by t tests.Results Pre-operatively,the mean corneal thickness was 535.17±32.352 μm with Orbscan-Ⅱsystem,and 545.43±29.079 μm with A-scan ultrasonography.Post-operatively,the mean corneal thickness with Orbscan-Ⅱsystem and with A-scan ultrasonography was 417.06±46.422 μm and 457.64±32.30 μm respectively,and the differences were statistically significant.Conclusion There is significant difference between the corneal thickness value measured by Orbscan-II topography system and ultrasonic pachymetry.Even high correlation between them has been showed,Orbscan-Ⅱsystem for corneal thickness measurement could not substitute A-scan ultrasonography completely.Certainly it still can be used as the very good reference for LASIK.