School of Engineering Science, Simon Fraser University, Burnaby, British Columbia, Canada.
Invest Ophthalmol Vis Sci. 2013 Apr 23;54(4):2864-71. doi: 10.1167/iovs.12-11521.
We compared the reproducibility and mutual agreement of the subfoveal choroidal thickness measurements by expert raters and an automated algorithm in enhanced depth imaging optical coherence tomography (EDI-OCT) images of eyes with nonneovascular age-related macular degeneration (AMD).
We recruited 44 patients with nonneovascular AMD and EDI-OCT images were acquired. Subfoveal choroidal thickness was measured manually by two expert raters and automatically by a graph-cut-based algorithm. Drusen area was measured using the automated software (version 6) of Cirrus SD-OCT. The manual and automated choroidal thickness measurements were compared in reproducibility, mutual agreement, and correlation with drusen area.
The mean subfoveal choroidal thickness was 246 ± 63 μm for the first rater, 214 ± 68 for the second rater, and 209 ± 53 for the automated algorithm. Intraclass correlation coefficients (ICC) and 95% confidence intervals (CI) were 0.96 (CI 0.94-0.98) between the raters, 0.85 (CI 0.77-0.90) between the first rater and the automated algorithm, and 0.84 (CI 0.75-0.89) between the second rater and the automated algorithm. Repeat scan measurement ICCs were 0.91 (CI 0.86-0.94) for the first rater, 0.96 (CI 0.94-0.97) for the second rater, and 0.87 (CI 0.80-0.92) for the automated algorithm. Manual and automated measurements were correlated with drusen area.
The automated algorithm generally yielded smaller choroidal thickness than the raters with a moderate level of agreement. However, its repeat scan measurement repeatability was comparable to that of the manual measurements. The mean difference between the raters indicated possible biases in different raters and rating sessions. The correlation of the automated measurements with the drusen area was comparable to that of the manual measurements. Automated subfoveal choroidal thickness measurement has potential use in clinical practice and clinical trials, with possibility for reduced time and labor cost.
我们比较了非新生血管性年龄相关性黄斑变性（AMD）患者的增强深度成像光学相干断层扫描（EDI-OCT）图像中专家评估者和自动算法的亚视盘脉络膜厚度测量的可重复性和相互一致性。
我们招募了 44 名患有非新生血管性 AMD 的患者，并采集了 EDI-OCT 图像。亚视盘脉络膜厚度由两位专家评估者手动测量，并由基于图形切割的算法自动测量。使用 Cirrus SD-OCT 的自动软件（版本 6）测量了玻璃膜疣的面积。比较了手动和自动脉络膜厚度测量的可重复性、相互一致性以及与玻璃膜疣面积的相关性。
第一位评估者的平均亚视盘脉络膜厚度为 246 ± 63μm，第二位评估者为 214 ± 68μm，自动算法为 209 ± 53μm。评估者之间的组内相关系数（ICC）和 95%置信区间（CI）分别为 0.96（CI 0.94-0.98），第一位评估者与自动算法之间为 0.85（CI 0.77-0.90），第二位评估者与自动算法之间为 0.84（CI 0.75-0.89）。第一次扫描测量的 ICC 分别为 0.91（CI 0.86-0.94）、0.96（CI 0.94-0.97）和 0.87（CI 0.80-0.92）。手动和自动测量与玻璃膜疣面积相关。
自动算法通常比评估者得出的脉络膜厚度小，一致性为中等水平。然而，其重复扫描测量的可重复性与手动测量相当。评估者之间的平均差异表明不同评估者和评估阶段可能存在偏差。自动测量与玻璃膜疣面积的相关性与手动测量相当。自动亚视盘脉络膜厚度测量具有在临床实践和临床试验中应用的潜力，有可能降低时间和劳动力成本。
