Lauermann J L, Woetzel A K, Treder M, Alnawaiseh M, Clemens C R, Eter N, Alten Florian
Department of Ophthalmology, University of Muenster Medical Center, Domagkstrasse 15, 48149, Muenster, Germany.
Graefes Arch Clin Exp Ophthalmol. 2018 Oct;256(10):1807-1816. doi: 10.1007/s00417-018-4053-2. Epub 2018 Jul 7.
To assess the prevalences of segmentation errors and motion artifacts in optical coherence tomography angiography (OCT-A) in different retinal diseases METHODS: In a retrospective analysis, multimodal retinal imaging including OCT-A was performed in one eye of 57 healthy controls (50.96 ± 22.4 years) and 149 patients (66.42 ± 14.1 years) affected by different chorioretinal diseases: early/intermediate age-related macular degeneration (AMD; n = 26), neovascular AMD (nAMD; n = 22), geographic atrophy due to AMD (GA; n = 6), glaucoma (n = 28), central serous chorioretinopathy (CSC; n = 14), epiretinal membrane (EM; n = 26), retinal vein occlusion (RVO; n = 11), and retinitis pigmentosa (RP; n = 16). Central 3 × 3 mm OCT-A imaging was performed with active eye-tracking (AngioVue, Optovue). Best-corrected visual acuity (BCVA) and signal strength index (SSI) were recorded. Images were independently evaluated by two graders using the OCT-A motion artifact score (MAS; scores I-IV) as well as a newly introduced segmentation accuracy score (SAS; score I-IIB).
Mean SSI was 63.67 ± 9.2 showing a negative correlation with increasing age (rSp = - 0.42, p < 0.001, n = 206). In the healthy cohort, mean MAS was 1.45 ± 0.8 and segmentation was accurate (SAS I) in all eyes. In eyes with retinal pathologies, mean MAS was 2.1 ± 0.9 (p < 0.001). Lowest MAS was observed in GA (2.67 ± 0.5) and RVO (2.45 ± 1.1). Compared to an accurate segmentation in 100% in healthy subjects, 34.2% (n = 51) of all patients showed highest segmentation quality (p < 0.001). 63.8% showed segmentation errors in more than 5% of all single b-scans in one (SAS IIA, n = 58) or at least two (SAS IIB, n = 40) segmentation boundaries. Highest percentages of inaccurate segmentation (SAS IIA or IIB) were observed in the nAMD group (90.1%). The inner plexiform layer was the segmentation boundary most prone to inaccurate segmentation in all pathologies compared to the inner limiting membrane (ILM) and retinal pigment epithelium (RPE) segmentation layer. Incorrect ILM segmentation was only seen in patients with EM.
Prior to both qualitative and quantitative analysis, OCT-A images must be carefully reviewed as motion artifacts and segmentation errors in current OCT-A technology are frequent particularly in pathologically altered maculae.
评估不同视网膜疾病患者光学相干断层扫描血管造影（OCT-A）中分割错误和运动伪影的发生率。方法：在一项回顾性分析中，对57名健康对照者（50.96±22.4岁）的一只眼睛以及149例受不同脉络膜视网膜疾病影响的患者（66.42±14.1岁）进行了包括OCT-A在内的多模式视网膜成像：早期/中期年龄相关性黄斑变性（AMD；n = 26）、新生血管性AMD（nAMD；n = 22）、AMD导致的地图样萎缩（GA；n = 6）、青光眼（n = 28）、中心性浆液性脉络膜视网膜病变（CSC；n = 14）、视网膜前膜（EM；n = 26）、视网膜静脉阻塞（RVO；n = 11）和视网膜色素变性（RP；n = 16）。使用主动眼动追踪技术（AngioVue，Optovue）进行中心3×3 mm的OCT-A成像。记录最佳矫正视力（BCVA）和信号强度指数（SSI）。由两名分级人员独立评估图像，使用OCT-A运动伪影评分（MAS；I-IV级评分）以及新引入的分割准确性评分（SAS；I-IIB级评分）。
平均SSI为63.67±9.2，与年龄增长呈负相关（rSp = -0.42，p < 0.001，n = 206）。在健康队列中，平均MAS为1.45±0.8，所有眼睛的分割均准确（SAS I）。在患有视网膜病变的眼睛中，平均MAS为2.1±0.9（p < 0.001）。在GA（2.67±0.5）和RVO（2.45±1.1）中观察到最低的MAS。与健康受试者100%的准确分割相比，所有患者中有34.2%（n = 51）表现出最高的分割质量（p < 0.001）。63.8%的患者在一个（SAS IIA，n = 58）或至少两个（SAS IIB，n = 40）分割边界处，超过5% 的单个b扫描中出现分割错误。在nAMD组中观察到不准确分割（SAS IIA或IIB）的百分比最高（90.1%）。与内界膜（ILM）和视网膜色素上皮（RPE）分割层相比，在内丛状层是所有病变中最容易出现不准确分割的分割边界。仅在EM患者中观察到ILM分割错误。
在进行定性和定量分析之前，必须仔细检查OCT-A图像，因为当前OCT-A技术中的运动伪影和分割错误很常见，尤其是在病理改变的黄斑中。
