Department of Ophthalmology, University Hospital, Uppsala, Sweden.
Acta Ophthalmol. 2012 Nov;90(7):620-7. doi: 10.1111/j.1755-3768.2011.02112.x. Epub 2011 Mar 4.
The aim of this study was to determine the variability of macular map measurements, for two generations of optical coherence tomography (OCT) instruments, in eyes with wet age related macular degeneration (AMD) and low visual acuity.
Patients were examined with Stratus OCT and Cirrus HD-OCT. The macular thickness was assessed with the 'macular thickness map scan' and 'fast protocol' in Stratus and with the 512 × 128 and 200 × 200 cube protocols in Cirrus OCT. Two measurements were taken one directly after the other, at the first visit to analyse repeatability. Approximately 1 week later, a third measurement was taken to analyse reproducibility. In Cirrus OCT, a manual correction of foveal location was also performed. Repeatability and reproducibility were calculated as a coefficient of variance (CoV) and a coefficient of repeatability/reproducibility.
Repeatability for central macular thickness (expressed as CoV) was about three per cent for all protocols, and the coefficient of repeatability between 34 and 54 μm. Reproducibility (also expressed as CoV) was between four to seven per cent and coefficient of repeatability between 64 and 89 μm. After manual adjustment of foveal location in Cirrus OCT, the coefficient of repeatability improved to 12-18 μm, and the coefficient of reproducibility to 44-47 μm.
In eyes affected by wet AMD, there were small differences in repeatability and reproducibility when comparing quantitative maps in Stratus and Cirrus OCT. However, when the software for manual correction of foveal position in Cirrus OCT was used, the variability decreased markedly, and the repeatability was close to what had been reported in normal eyes, demonstrating a significant, potential advantage of spectral-domain over time-domain OCT.
本研究旨在确定两种一代光学相干断层扫描（OCT）仪器在湿性年龄相关性黄斑变性（AMD）和低视力眼中黄斑图测量的可变性。
患者使用 Stratus OCT 和 Cirrus HD-OCT 进行检查。使用 Stratus 的“黄斑厚度图扫描”和“快速协议”以及 Cirrus OCT 的 512×128 和 200×200 立方体协议评估黄斑厚度。在第一次就诊时，直接进行两次测量以分析重复性。大约 1 周后，进行第三次测量以分析可重复性。在 Cirrus OCT 中，还进行了黄斑中心凹位置的手动校正。重复性和可重复性的计算方法为变异系数（CoV）和可重复性/可再现性系数。
所有协议的中央黄斑厚度（表示为 CoV）的重复性约为 3%，可重复性系数在 34 和 54 μm 之间。再现性（也表示为 CoV）在 4%至 7%之间，可重复性系数在 64 和 89 μm 之间。在 Cirrus OCT 中手动调整黄斑中心凹位置后，可重复性系数提高到 12-18 μm，可重复性系数提高到 44-47 μm。
在患有湿性 AMD 的眼中，Stratus 和 Cirrus OCT 中定量图的重复性和可再现性比较时，差异较小。然而，当使用 Cirrus OCT 中用于手动校正黄斑中心凹位置的软件时，变异性明显降低，并且可重复性接近正常眼的报道，这表明与时间域 OCT 相比，光谱域 OCT 具有显著的潜在优势。
