Rougier Marie-Benedicte, Gattoussi Sarra, Le-Goff Melanie, Korobelnik Jean Francois
Ophthalmology Department, Bordeaux University Hospital, Bordeaux, France.
University of Bordeaux, Institut National de la Sante et de la Recherche Medicale (INSERM), Bordeaux Population Health Research Center, Team LEHA, Bordeaux, France.
Eur J Ophthalmol. 2021 Nov;31(6):3471-3475. doi: 10.1177/1120672120978358. Epub 2020 Dec 14.
In non-arteritic anterior ischemic optic neuropathy (NAION), optical coherence tomography angiography (OCTA) shows changes in peripapillary vascularization. However, the presence of an optic disc edema may induce artifacts that prevent visualizing the peripapillary network. The aim of this study was to evaluate the peripapillary vascularization in acute NAION using swept-source OCTA algorithms allowing segmenting only the retinal nerve fiber layer (RNFL).
Retrospective analysis of 15 eyes with acute NAION of 15 patients. The optic nerve head was imaged using swept-source OCTA. Morphological and quantitative analyzes were performed. The capillary flux index (CFI), defined as the total weighted area of perfused vasculature per unit area, and the capillary perfusion density (CPD), defined as the total area of perfused microvasculature per unit area, were quantified. Each NAION eye was compared to the unaffected fellow eye using a Wilcoxon test for matched samples.
After segmentation at the RNFL, the morphological analysis showed less vascular dropout and more vascular tortuosity than the analysis of a larger segmentation. The quantitative analysis showed that the mean CFI and the CFI in the four quadrants were significantly higher in NAION eyes compared to healthy eyes ( = 0.0002 and < 0.01). The mean CPD and the CFD in the inferior quadrant were lower in NAION eyes ( = 0.03 and = 0.0054, respectively).
The RNFL segmentation allowed better visualizing the peripapillary network because the edema related darkening was reduced. The increased CFI suggests an autoregulatory phenomenon to compensate the ischemic process at the ciliary vasculature.
在非动脉炎性前部缺血性视神经病变（NAION）中，光学相干断层扫描血管造影（OCTA）显示视乳头周围血管化的变化。然而，视盘水肿的存在可能会产生伪影，妨碍对视乳头周围网络的观察。本研究的目的是使用扫频源OCTA算法评估急性NAION患者视乳头周围的血管化情况，该算法仅允许分割视网膜神经纤维层（RNFL）。
对15例急性NAION患者的15只眼进行回顾性分析。使用扫频源OCTA对视神经乳头进行成像，并进行形态学和定量分析。对毛细血管通量指数（CFI，定义为单位面积内灌注血管的总加权面积）和毛细血管灌注密度（CPD，定义为单位面积内灌注微血管的总面积）进行量化。使用配对样本的Wilcoxon检验将每只NAION眼与未受影响的对侧眼进行比较。
在RNFL进行分割后，形态学分析显示与更大范围分割的分析相比，血管缺失更少，血管迂曲更多。定量分析显示，与健康眼相比，NAION眼中的平均CFI和四个象限中的CFI显著更高（分别为=0.0002和<0.01）。NAION眼中的平均CPD和下象限中的CFD较低（分别为=0.03和=0.0054）。
RNFL分割能够更好地观察视乳头周围网络，因为与水肿相关的暗化减少。CFI增加表明存在一种自动调节现象，以补偿睫状血管系统的缺血过程。
