Orbscan Ⅱ眼前节分析系统和Pentacam眼前节分析系统测量屈光手术前后角膜屈光力的差异

Orbscan Ⅱ versus Pentacam anterior eye segment analysis systems for measurement of corneal power before and after refractive surgery

背景:Orbscan Ⅱ眼前节分析系统和Pentacam眼前节分析系统均能对角膜前后表面屈光力进行测量,但两者结果的一致性、精确性尚无定论。目的:利用2种不同眼前节分析系统对屈光手术前后的角膜前后表面屈光力进行测量,分析2种仪器的可靠性,及角膜屈光手术对角膜后表面形态的影响。方法:纳入2010-02/04在广东省人民医院屈光手术中心连续就诊的近视患者69例患者(136眼),行准分子激光原位角膜磨镶33例65眼和准分子激光上皮下角膜磨镶36例71眼,比较Orbscan Ⅱ眼前节分析系统和Pentacam眼前节分析系统检测不同手术方法的角膜前后表面3mm平均轴向屈光力和的测量值。结果与结论:屈光手术前后,2种仪器前后表面屈光力测量值的差异有显著性意义。后表面屈光力的Orbscan Ⅱ眼前节分析系统测量值在术后均变小,而Pentacam眼前节分析系统测量值无显著改变。Orbscan Ⅱ眼前节分析系统测量的后表面屈光力变化值与残余基质层厚度存在线性相关。提示2种仪器的测量结果不能相互替代使用。后表面屈光力,在屈光手术前Pentacam眼前节分析系统测量值较小,但在屈光手术后则相反,Pentacam眼前节分析系统并未发现Orbscan Ⅱ眼前节分析系统测量出的术后后表面前突。

BACKGROUND： Orbscan Ⅱ anterior eye segment analysis system and Pentacam anterior eye segment analysis system can both measure the cornea power before and after refractive surgery. But the consistency and accuracy of the two mentioned above remain unclear. OBJECTIVE： Using the two kinds of anterior eye segment analysis systems to measure the cornea power before and after refractive surgery, and to analyze the reliability of the two instruments and the effect of corneal refractive surgery on morphology of posterior corneal surface. METHODS： Sixty-nine cases of myopia （136 eyes） who were continuously treated in the Refractive Surgery Center of Peoples Hospital of Guangdong Province from 2010-02/04 were included. Thirty-three cases （65 eyes） received laser in situ keratomileusis （LASIK） and 36 cases （71 eyes） underwent laser subepithelial keratomileusis （LASEK）. Then, OrbscanⅡ and Pentacam anterior eye segment analysis systems were used to measure posterior and anterior corneal power. RESULTS AND CONCLUSION： There was a significant difference in anterior/posterior corneal power measurements between the two instruments. The consistency was well. Orbscan ]I found that posterior coneal power became smaller after LASIK/LASEK; while Pentacam found no significant difference. There was a linear correlation between the change values of posterior cornear power and residual bed thickness. These findings suggest that the results measured by Orbscan Ⅱ and Pentacam anterior eye segment analysis systems cannot replace each other. For posterior corneal power, Pentacam anterior eye segment analysis system showed low measurements before refractive surgery, but the measurements were converse after refractive surgery. Besides, Orbscan Ⅱ found posterior surface protrusion, but Pentacam did not.