方法：选择2012-07/10圆锥角膜患者31例55眼，分别使用A型超声角膜测厚仪、角膜内皮镜和Pentacam眼前节分析仪测量中央角膜厚度，并对测量结果进行F检验和Pearson相关性分析。

结果：A型超声(55眼)、角膜内皮镜(45眼)和Pentacam(52眼)测量值分别为469.87±57.56， 479.00±42.39，487.02±44.64μm，三者测量值结果相比差异没有统计学意义(P>0.05)。对三种仪器的测量结果进行直线相关分析，A型超声与角膜内皮镜，r₁=0.758，P<0.01； A型超声与Pentacam眼前节分析仪，r₂=0.949，P<0.01； Pentacam眼前节分析仪与角膜内皮镜，r₃=0.685，P<0.01。

结论：三种仪器的中央角膜厚度测量值存在正相关，Pentacam眼前节分析仪测量角膜厚度不仅与A超结果更接近，而且方法安全简便，全面反应角膜各点厚度，更适用于圆锥角膜患者的角膜厚度检查及科研研究。

METHODS: Between July 2012 and October 2012, the CCT of 31 patients(55 eyes)were measured by A-scan, corneal specular microscopy and Pentacam. The results were analyzed by F-test and Pearson correlation.

RESULTS: The values of CCT measured by A-scan(55 eyes), corneal specular microscopy(45 eyes)and Pentacam(52 eyes)were 469.87±57.56, 479.00±42.39, and 487.02±44.64μm, respectively; F-test results showed there were no statistical significant differences between CCT measured by three different instruments(P>0.05). The correlation between the measurements was evaluated using Pearson correlation coefficients. The CCT values by these three instruments were positively related by linear correlation analysis, A-scan and Pentacam measurements(r₁=0.758, P<0.01), A-scan and Pentacam(r₂=0.949, P<0.01), corneal specular microscopy and Pentacam(r₃=0.685, P<0.01).

CONCLUSION: There is a high correlation between these three instruments. A-scan and Pentacam are more precise than corneal specular microscopy. Pentacam system can measure the CCT easily, accurately and without any invasion. It is more suitable for people with keratoconus to monitor the every point of cornea and for people to do more deep research.