正常人眼视网膜神经纤维层的OCT光学特征定量测量的可重复性

目的评估使用光学相干断层扫描（OCT）定量测量视网膜神经纤维层（RNFL）光学特征的可重复性。方法横断面研究。共连续纳入正常受检者50例（50眼），应用Cirrus OCT的5线高清扫描模式和视盘数据方模式，在1 d内的不同时间获取RNFL的原始图像数据，并通过2位检查者在双盲情况下使用自编程图像处理软件分析RNFL的光学特征，包括吸光度和吸光系数。运用组内标准差，组内相关系数（ICC），变异系数（COVs）和Bland-Altman方法来评估OCT光学特征定量测量和自编程图像分析软件的可重复性。结果受检者的年龄为（51.2±8.1）岁。黄斑区/视盘周边区RNFL厚度、吸光度和吸光系数分别为（34.38±3.45）µm/（89.07±3.19）µm、（117.90±6.02）灰度/（138.10±18.25）灰度和（1.99±0.16）/（3.48±0.64）。RNFL厚度、吸光度以及吸光系数的ICC为0.712～0.952，COVs为2.20%～6.54%。黄斑区/视盘周边区RNFL吸光度OCT 2次测量结果之间的平均偏差分别为-0.01灰度/0.33灰度，吸光系数为0.01/-0.01。自编程图像处理软件测量的RNFL厚度、吸光度及吸光系数的ICC为0.928~0.979，COVs均小于6%（1.35%~4.24%）。结论OCT光学特征定量测量和自编程图像分析软件定量测量RNFL光学特征可取得较高的可重复性。

Repeatability of the optical characteristics of the retinal nerve fiber layer measured with optical coherence tomography

ObjectiveTo determine the repeatability of the optical characteristics of the retinal nerve fiber layer （RNFL） measured with optical coherence tomography （OCT） in healthy Chinese individuals. MethodsIn this cross-sectional study， 50 eyes of 50 normal subjects were consecutively recruited. RNFLs were imaged twice using a Cirrus OCT device with a 5-line raster macular scan and an optic disc cube mode in one day by a single operator. Customized software was used to measure RNFL optical characteristics， including optical density and the attenuation coefficient. Repeatability of OCT and customized software measurements were described by intraclass correlation coefficients （ICCs）， coefficients of variation （COVs） and the Bland-Altman method. ResultsThe mean and standard deviation of age were 51.2±8.1 years. The mean and standard deviations of macular RNFL thickness， optical density and the attenuation coefficient were 34.38±3.45 µm， 117.90±6.02 grey and 1.99±0.16， respectively. The mean and standard deviations of optic disc RNFL thickness， optical density and the attenuation coefficient were 89.07±3.19 µm， 138.10±18.25 grey and 3.48±0.64， respectively. All the evaluated RNFL parameters had good to excellent reproducibility. ICC ranged from 0.712 to 0.952 and COV ranged from 2.20% to 6.54%. The bias between two OCT measurements were -0.01 grey/0.33 grey and 0.01/-0.01， respectively， for macular and optic disc RNFL optical density and attenuation coefficients. Customized software showed excellent reproducibility in RNFL measurements. ICC ranged from 0.928 to 0.979 and COVs all bellowed 6%（1.35%-4.24%） for RNFL parameters measurement. ConclusionIn our population of normal adult Chinese eyes， there is good repeatability of RNFL optic characteristics measured by OCT and customized software.