三种仪器测量中央角膜厚度的比较

Comparison of Central Corneal Thickness Measured by Three Kinds of Instruments

【目的】探讨光学相干断层扫描仪(OCT)、超声波角膜测厚仪及OrbscanⅡ角膜地形图/角膜测厚系统(OrbscanⅡ系统)测量中央角膜厚度(CCT)的差异及测量的可重复性。【方法】分别用OCT、超声波角膜测厚仪和OrbscanⅡ系统测量近视患者34例(68只眼)的CCT并对测量值进行比较,用相关分析方法分析不同仪器间测量值的相关性;随机选择15例(30只眼)用三种仪器依次重复测量中央角膜厚度3次,采用方差分析方法分析3种仪器重复测量值的方差。【结果】OCT、超声波角膜测厚仪、OrbscanⅡ系统测得的CCT平均值分别为(515±33)"m、(535±35)"m和(534±44)"m,OCT的测量值比超声波角膜测厚仪与OrbscanⅡ的测量值小,差异有统计学意义(P值分别为0.004和0.003),超声波角膜测厚仪与OrbscanⅡ的测量值差异无统计学意义(P=0.900)。OCT测量的CCT值与超声波角膜测厚仪(r=0.980,P<0.001)和OrbscanⅡ系统(r=0.963,P<0.001)测量的CCT值呈正相关。OCT、超声波角膜测厚仪、OrbscanⅡ系统CCT重复测量值的方差分别为(3.75±3.05)、(6.53±3.02)和(5.26±2.98)。OCT的方差与超声波角膜厚度测量仪比较差异有统计学意义(P=0.001),与OrbscanⅡ系统比较差异无统计学意义(P=0.083)。【结论】OCT测量的CCT值最小;OCT与超声波角膜测厚仪和ObscanⅡ系统对CCT测量值的相关性较好;OCT测量CCT的可重复性较好,可以作为中央角膜厚度测量的工具。

To investigate the difference of central corneal thickness （CCT） measured by optical coherence tomography （OCT）, ultrasonic pachymeter and Orbscan Ⅱ system and compare their repeatability. [Methods] The CCT of 68 eyes of 34 patients with myopia were measured by OCT, ultrasound pachymeter, and Orbscan Ⅱ, respectively. The data was analyzed using ANOVA and correlation methods. CCT of thirty eyes from 15 cases selected randomly were measured 3 times by above 3 kinds of instruments, respectively, and the variance of repeated measurements of 3 kinds of instruments was analyzed using ANOVA. [Results] The average CCT measured by OCT, ultrasound pachymeter, and Orbscan Ⅱ were （515±33）μm,（535±35）μm, and （534±44）μm, respectively. There was significant difference of CCT between using of OCT and using of ultrasound pachymeter（P= 0.004）, Orbscan Ⅱ （P=0.003）, while no significant difference between ultrasound pachymeter and Orbscan Ⅱ （P= 0.900）. There were positive correlationship between CCT with OCT and ultrasound pachymetry, Orbscan Ⅱ, r= 0.980 and 0.963, P〈 0.001. The variances of CCT by OCT, ultrasound pachymetry, and Orbscan Ⅱ of repetitive measurements were （ 3.75 ±3.05 ）, （ 6.53 ±3.02 ）, and （ 5.26 ±2.98 ）, respectively and there was significant difference of CCT between OCT and ultrasound pachymetry （P=0.001）, but was no significant difference between OCT and Orbscan Ⅱ （P=0.083）. [Conclusions] The mean CCT measured by OCT is the least. There are excellent correlationship between OCT and ultrasound pachymetry, Orbscan Ⅱ in CCT measurement. The repeatability of CCT by OCT are excellent,its could be aplied to CCT measurement.