Le Qihua, Chen Yan, Yang Yujing, Xu Jianjiang
Department of Ophthalmology, Eye & ENT Hospital of Fudan University, No. 83 Fenyang Road, Shanghai, 200031, China.
Research Center, Eye & ENT Hospital of Fudan University, Shanghai, 200031, China.
BMC Ophthalmol. 2016 Sep 20;16(1):163. doi: 10.1186/s12886-016-0342-x.
To compare corneal epithelial thickness (CET) and limbal epithelial thickness (LET) measured by anterior segment optical coherence tomography (AS-OCT) and in vivo confocal microscope (IVCM) in normal subjects, and evaluate the consistency between them.
Thirty-eight normal subjects (17 men and 21 women) were enrolled in this study. AS-OCT was performed at central cornea and the superior, inferior, nasal and temporal limbus. Then followed by IVCM examination performed at the same location. Agreement was analyzed by mean difference (AS-OCT minus IVCM), 95 % limits of agreement (LoA) (1.96 standard deviation of the difference), and Bland-Altman analysis.
The average CET measured by AS-OCT and IVCM was 55.6 ± 4.0 μm and 51.9 ± 4.9 μm respectively. The value measured by IVCM was significantly lower than that measured by AS-OCT (P = 0.015). The average LET values tested by AS-OCT were 10.3 and 10.9 % less at nasal and temporal quadrant (nasal: P = 0.019, temporal: P = 0.003), and were similar as those measured by IVCM at superior and inferior quadrant. In subjects older than 40 years, CET and LET values measured by AS-OCT were significantly higher than those by IVCM. Such differences were not found in subjects ≤ 40 years old.
CET values measured by IVCM are lower than those by AS-OCT, while LET values measured by two devices have good agreement. These two techniques have their own advantages in measuring epithelial thickness and are mutually complementary.
比较正常受试者中通过眼前节光学相干断层扫描（AS-OCT）和活体共聚焦显微镜（IVCM）测量的角膜上皮厚度（CET）和角膜缘上皮厚度（LET），并评估两者之间的一致性。
本研究纳入38名正常受试者（17名男性和21名女性）。在中央角膜以及上方、下方、鼻侧和颞侧角膜缘进行AS-OCT检查。然后在相同位置进行IVCM检查。通过平均差异（AS-OCT减去IVCM）、95%一致性界限（LoA）（差异的1.96倍标准差）和Bland-Altman分析来分析一致性。
AS-OCT和IVCM测量的平均CET分别为55.6±4.0μm和51.9±4.9μm。IVCM测量的值显著低于AS-OCT测量的值（P = 0.015）。AS-OCT检测的鼻侧和颞侧象限的平均LET值分别低10.3%和10.9%（鼻侧：P = 0.019，颞侧：P = 0.003），与IVCM在上方和下方象限测量的值相似。在40岁以上的受试者中，AS-OCT测量的CET和LET值显著高于IVCM测量的值。在≤40岁的受试者中未发现此类差异。
IVCM测量的CET值低于AS-OCT测量的值，而两种设备测量的LET值具有良好的一致性。这两种技术在测量上皮厚度方面各有优势，且相互补充。
