三种光学测量仪器与A超对近视眼中央角膜厚度测量的对比研究

Comparison of central corneal thickness measured by three optical measurement devices with ultrasound pachymetry

摘要:

目的：探讨眼前段光学相干断层扫描仪(Visante OCT)、裂隙灯型眼前段光学相干断层扫描仪(SL-OCT)、OrbscanⅡz角膜地形图/角膜测厚系统(OrbscanⅡz)和A型超声测量仪测量近视人群中央角膜厚度(central corneal thickness，CCT)的差异及相关性，以评价三种光学测量仪器在测量中央角膜厚度的准确性，为其临床应用提供依据。

方法：对近视患者43 例86眼分别用Visante OCT、SL-OCT、OrbscanⅡz和A型超声测量仪进行CCT的测量，并对四种仪器测量的CCT值采用单因素方差分析， LSD-t法两两比较，Pearson相关分析。

结果：Visante OCT、SL-OCT、OrbscanⅡz和A型超声测量仪测量CCT的平均值分别为(521.05±29.88)μm、(533.73±31.83)μm、(534.02±32.96)μm、(540.60±31.11)μm，95%可信区间分别为(514.57～527.54)，(526.83～540.65)，(533.85～547.35)，(536.75～544.45)。Visante OCT 与SL-OCT(P=0.009)、A型超声测量仪(P<0.01)、OrbscanⅡz(P=0.008)的CCT测量值差异均有统计学意义。Visante OCT的CCT测量值分别低于SL-OCT的CCT测量值(12.69±9.32)μm，低于A型超声测量仪的CCT测量值(19.55±8.64)μm，低于OrbscanⅡz的CCT测量值(12.96±12.21)μm。SL-OCT与A型超声测量仪(P=0.158)、OrbscanⅡz(P=0.954)的CCT测量值差异均无统计学意义。OrbscanⅡz与A型超声测量仪的CCT测量值差异无统计学意义(P=0.176)。四种方法CCT测量值均呈正相关(P<0.01)。

结论：三种光学测量仪器测量CCT值与A超测量值均有很好的相关性。OrbscanⅡz和SL-OCT测量CCT值与A超的测量值基本一致。三种光学测量仪器与A超相比具有非接触性、无创性、测量时间短等特点，更易被患者接受。

Abstract:

AIM:To compare the difference and correlation of central corneal thickness(CCT)measured by Zeiss Visante Anterior Segment Optical Coherence Tomography(Visante OCT), Heidelberg Slit-Lamp Anterior Segment Optical Coherence Tomography(SL-OCT), OrbscanⅡz Computerized Topography(OrbscanⅡz )and A-mode ultrasound pachymetry.

METHODS:Forty-three patients with myopia(86 eyes)were included. Sequential measurements of CCT was performed by the same operator with two different anterior segment OCT devices(Visante^TM, Carl Zeiss, Meditec and Heidelberg Engineering^TM), OrbscanⅡz Computerized Topography(Bausch and Lomb Inc^TM)and A-mode ultrasound pachymetry. The consistency of measurements was statistically analyzed by one-way ANOVA and LSD pair-wise comparisons. The differences were analyzed by Pearson correlation coefficients.

RESULTS:The average CCT measured by Visante OCT, SL-OCT, OrbscanⅡz, and A-mode ultrasound pachymetry were(521.05±29.88)μm,(533.73±31.83)μm,(534.02±32.96)μm, and(540.60±31.11)μm, the 95% confidence interval were(514.57～527.54),(526.83～540.65),(533.85～547.35),(536.75～544.45). There was statistically significant difference of CCT between using of Visante OCT and SL-OCT(P=0.009). There was statistically significant difference of CCT using of Visante OCT and A-mode ultrasound pachymetry(P<0.01), OrbscanⅡz(P=0.008). The Visante OCT CCT measurements was significantly less than CCT with SL-OCT(12.69±9.32)μm. Compare with A-mode ultrasound pachymetry and OrbscanⅡz, the Visante OCT measurements significantly underestimated central corneal thickness by a mean of(19.55±8.64)μm and(12.96±12.21)μm. There was no significant difference of CCT between using of SL-OCT and A-mode ultrasound pachymetry(P=0.158), OrbscanⅡz(P=0.954). There was no significant difference of CCT between using of OrbscanⅡz and A-mode ultrasound pachymetry(P=0.176). There were positive correlationship among Visante OCT, SL-OCT, OrbscanⅡz, and A-mode ultrasound pachymetry in CCT measurement(P<0.01).

CONCLUSION:There are excellent correlationship among Visante OCT, SL-OCT,OrbscanⅡz, and A-mode ultrasound pachymetry in CCT measurement. The data shows that the CCT obtained by SL-OCT and OrbscanⅡz do not have significant difference as compared with that from the A-mode ultrasound pachymetry. Three optical measurement devices is more likely to be accepted by patients because of its non-contact, non-invasive, and short measurement time as compared with the A-mode ultrasound pachymetry.