Leung Dexter Y L, Lam Douglas K T, Yeung Barry Y M, Lam Dennis S C
Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, Kowloon, Hong Kong, China.
Clin Exp Ophthalmol. 2006 Nov;34(8):751-4. doi: 10.1111/j.1442-9071.2006.01343.x.
Measurement of central corneal thickness (CCT) plays an important role in both diagnostic and therapeutic assessment of ocular diseases. Although ultrasound pachymetry (U-PACH) is regarded as the golden standard for measurement of CCT, optical coherence tomography (OCT) may offer advantages as it can locate the central cornea with precision with no corneal touch. Nevertheless, the agreement of OCT with U-PACH has not yet been gauged by Bland-Altman analysis. This study compares CCT measurement by OCT with that by U-PACH.
Healthy subjects without ocular abnormality (except refractive errors less than or equal to -6.0 D), contact lens wear or ocular surgery were recruited. CCT was measured in one eye of normal subjects using OCT and U-PACH. Results were compared using correlation and Bland-Altman plots.
Fifty subjects were recruited. Mean +/- SD CCT measured by OCT was 565 +/- 33 microm. This was highly correlated (Pearson's coefficient = 0.934) with the mean thickness measured by U-PACH (543 +/- 33 microm). The coefficients of variation were good and comparable at 7.9% for U-PACH and 3.5% for OCT. Compared with U-PACH, OCT consistently overestimated the CCT by a mean of 23 microm as shown on Bland-Altman plot.
CCT measured by OCT and U-PACH is highly correlated. With appropriate adjustment factor, OCT agrees well with U-PACH and is a reliable alternative for CCT measurement.
中央角膜厚度（CCT）测量在眼科疾病的诊断和治疗评估中均发挥着重要作用。尽管超声测厚法（U-PACH）被视为测量CCT的金标准，但光学相干断层扫描（OCT）可能具有优势，因为它能够精确地定位中央角膜且无需接触角膜。然而，尚未通过Bland-Altman分析来评估OCT与U-PACH测量结果的一致性。本研究比较了OCT与U-PACH测量CCT的结果。
招募无眼部异常（除屈光不正小于或等于-6.0 D）、未佩戴隐形眼镜或未接受眼部手术的健康受试者。使用OCT和U-PACH测量正常受试者一只眼睛的CCT。使用相关性分析和Bland-Altman图比较结果。
共招募了50名受试者。OCT测量的平均±标准差CCT为565±33微米。这与U-PACH测量的平均厚度（543±33微米）高度相关（Pearson系数=0.934）。U-PACH的变异系数为7.9%，OCT的变异系数为3.5%，二者均良好且具有可比性。Bland-Altman图显示，与U-PACH相比，OCT始终高估CCT，平均高估23微米。
OCT和U-PACH测量的CCT高度相关。通过适当的校正因子，OCT与U-PACH测量结果一致性良好，是一种可靠的CCT测量替代方法。
