三种仪器测量中央角膜厚度的比较和前节OCT测量上皮厚度的分析

目的 分析比较A超、Pentacam前节分析系统、前节OCT测量中央角膜厚度(CCT)的差异性;了解角膜上皮厚度与中央厚度的相互关系。方法 选取2013-08～2013-09在陕西武警总队医院准分子激光中心术前检查的屈光不正患者180例(360眼)。用A超、Pentacam系统、前节OCT三种仪器分别测量以上患者的中央角膜厚度,并由前节OCT测量角膜中央上皮厚度。三种仪器测量CCT的差异用单因素方差分析(SNK),相关性采用Pearson相关分析。三种仪器的一致性用B1and-Altman分析。前节OCT测量中央角膜上皮厚度与前节OCT测量中央角膜厚度的相关性用Pearson相关分析。用SPSS16软件对采集数据进行统计学分析。结果 A超、Pentacam、前节OCT测量角膜中央厚度分别为(530.56±26.75)μm、(542.40±26.34)μm、(520.55±26.15)μm;SNK法所示三种仪器测量结果差异具有统计意义(P＜0.05)。三种仪器测量CCT的Pearson相关系数均大于0.9,显示三种仪器两两间具有高度相关性(r₁=0.922,r₂=0.960,r₃=0.924)。A超和Pentacam、A超与前节OCT、Pentacam与前节OCT测量CCT在95%的一致性区间分别为(-32.46~8.79)μm、(-4.71~24.74)μm、(1.73~41.96)μm,结合Bland-Altman图,提示三种仪器两两间测CCT有较好的一致性。前节OCT测量中央角膜上皮厚度为(49.82±4.04)μm,它所测CCT的相关性分析显示两者没有统计学意义(P＞0.05)。结论 与A超测CCT结果相比,Pentacam测的结果偏厚,前节OCT测量的结果偏薄。三种光学测量仪器测量CCT值两两之间均有很好的相关性。前节OCT测的角膜上皮厚度与角膜中央厚度没有相关性。

Comparison of central corneal thickness measured by three kinds of instruments and study on the corneal epithelial thickness measured by AS-OCT

Objective To compare the difference of central corneal thickness（CCT） measured by anterior segment optical coherence tomography（AS-OCT）,Pentacam and A-mode ultrasound,and then further analysis of the relationship between corneal epithelial thickness and central thickness.Methods AS-OCT,Pentacam and A-mode ultrasound were used to measure the CCT on 180 myopiccases（360eyes） undergoing laser in situ keratomileusis（LASIK）,and then the results of the collected data were compared.Results The value of CCT measured by AS-OCT,Pentacam and A-mode ultrasound were（530.5 ± 26.75） μm,（542.40 ± 26.34） μm and（520.5 ± 26.15）μm,respectively.There was a significant linear correlation in CCT measured by the three measurements（P〈0.0 5）.Pearson correlation coefficient of measured value by the three kinds of instruments were more than 0.9（r1= 0.922,r2= 0.960,r3= 0.924）,which means there are highly correlation between each other.The 95% of the consistency interval of A-mode and Pentacam,A-mode and AS-OCT,Pentacam and AS-OCT were（-32.46 - 8.79） μm,（-4.71 - 24.74） μm and（1.73 - 41.96） μm,respectively.AS-OCT measurement of central corneal epithelial thickness was（49.82 ± 4.04） μm,and the CCT correlation analysis showed there was no statistical significance（P〈0.05）.Conclusion The CCT measurement results of Pentacam were thicker,while anterior segment OCT were thinner compared with of A-mode.Pearson correlation coefficient of three optical measuring instruments to measure the CCT values have very good correlation between any of two.The thickness of the corneal epithelium and corneal central thickness measured by AS-OCT is no correlation.