Eye Center, Faculty of Medicine, University of Freiburg, Killianstrasse 5D-79106, Freiburg, Germany.
Faculty of Medicine, University of Freiburg, Freiburg, Germany.
Int Ophthalmol. 2020 Aug;40(8):2007-2016. doi: 10.1007/s10792-020-01376-7. Epub 2020 Apr 24.
To characterize the choriocapillaris (CC) structure in relation to subretinal fluid (SRF) as a possible systematic error source using spectral domain (SD-OCTA) compared to swept-source optical coherence tomography angiography (SS-OCTA).
This is a prospective case-control study of 23 eyes. Ten patients with acute central serous chorioretinopathy (CSC), three patients with partial macular-off retinal detachment (RD) and ten healthy, age-matched controls were included. Abnormal CC decorrelation signals were quantitatively compared in CSC and controls by means of custom image processing. To investigate the influence of SRF on CC OCTA signal, the extent of SRF was quantified with a macular heatmap and compared with the corresponding OCTA signal of the CC.
SS-OCTA yielded a more homogeneous OCTA signal from the CC than SD-OCTA, offering less signal dispersion and variability in healthy and diseased eyes. Both devices demonstrated CC signal voids in CSC and RD, respectively. In CCS, the voids were predominantly located in the area with SRF. Compared to SD-OCTA, SS-OCTA delivered a more homogenous OCTA signal and reduced signal voids in the CC underneath SRF in both RD and CSC (CSC, 7.6% ± 6.3% vs, 19.7% ± 9.6%, p < 0.01). Despite this significant attenuation of signal voids, SS-OCTA continued to reveal signal voids below SRF and more pixels with reduced OCTA signals in CSC patients compared to controls (7.6% ± 6.3%, 0.1% ± 0.1%, p < 0.0001).
Understanding OCTA artifacts is critical to ensure accurate clinical evaluations. In this study, we describe the presence of SRF as an important shadow-causing artifact source for CC OCTA analysis which can be mitigated but not completely eliminated by employing SS-OCTA.
利用谱域（SD-OCTA）与扫频源光学相干断层扫描血管造影术（SS-OCTA）相比，分析脉络膜毛细血管（CC）结构与视网膜下液（SRF）的关系，探讨其是否为系统性误差源。
本研究为前瞻性病例对照研究，共纳入 23 只眼。纳入对象为 10 例急性中心性浆液性脉络膜视网膜病变（CSC）患者、3 例部分性黄斑区视网膜脱离（RD）患者和 10 例年龄匹配的健康对照者。采用定制的图像处理方法对 CSC 患者和对照组患者的异常 CC 去相关信号进行定量比较。为了研究 SRF 对 CC OCTA 信号的影响，通过黄斑热图量化 SRF 的范围，并与相应的 CC OCTA 信号进行比较。
与 SD-OCTA 相比，SS-OCTA 提供了更均匀的 CC OCTA 信号，在健康眼和病变眼中信号的离散度和可变性更小。两种设备均显示 CSC 和 RD 中存在 CC 信号缺失。在 CSC 中，这些缺失主要位于 SRF 区域。与 SD-OCTA 相比，SS-OCTA 在 RD 和 CSC 中均能减少 SRF 下方 CC 的 OCTA 信号缺失（CSC：7.6%±6.3%比 19.7%±9.6%，p<0.01）。尽管信号缺失明显减少，但 SS-OCTA 在 CSC 患者中仍能显示 SRF 下方的信号缺失，以及更多的 OCTA 信号降低的像素（7.6%±6.3%比 0.1%±0.1%，p<0.0001）。
了解 OCTA 伪影对于确保准确的临床评估至关重要。在本研究中，我们描述了 SRF 作为 CC OCTA 分析中重要的阴影伪影来源的存在，通过采用 SS-OCTA 可以减轻但不能完全消除该伪影。
