Vessel Density and Vessel Tortuosity Quantitative Analysis of Arteritic and Non-arteritic Anterior Ischemic Optic Neuropathies: An Optical Coherence Tomography Angiography Study

Abstract

The aim of this study was to perform quantitative optical coherence tomography angiography (OCTA) assessment of arteritic and non-arteritic anterior ischemic optic neuropathies (AION; NAION). The study was designed as an observational, cross-sectional case series. All patients underwent complete ophthalmologic evaluation including LogMAR best-corrected visual acuity (BCVA), structural optical coherence tomography (OCT) and OCTA images, and dye-based angiography. Retinal nerve fiber layer (RNFL) thickness was obtained from structural OCT, and vessel density (VD) and vessel tortuosity (VT) were measured for each optic nerve head vascular plexus. After selecting the quadrants showing visual field defects, measured by Humphrey 30.2 perimetry (Zeiss Meditec, Dublin, CA, USA), we assessed the correlation between the localization of visual field defects and the quadrants showing impairments of RNFL, VD, and VT. Thirty naïve AION patients (15 arteritic AION (AAION) and 15 non-arteritic AION (NAION)) were included. LogMAR BCVA was 0.6 ± 0.2 for AAION and 0.3 ± 0.3 for NAION (p < 0.01). AAION and NAION eyes showed significant differences in terms of visual field involvement as well as VD and VT values, with remarkably worse alterations affecting AAION eyes. VD values perfectly matched with the quadrants showing RNFL and visual field defects. On the contrary, VT resulted remarkably decreased in all the quadrants, with even worse values in the quadrants showing RNFL and visual field alterations. The present study showed that AAION eyes are more injured than NAION ones. VD represents a good parameter for the detection of the main site on vascular impairment. Remarkably, VT resulted in a more sensitive parameter for the quantitative detection of blood flow impairment in AION disease.

Optical Coherence Tomography Angiography Assessment of the Peripapillary Vessel Density and Structure in Patients with Nonarteritic Anterior Ischemic Optic Neuropathy: A Meta-Analysis

“…However, substantial heterogeneity was shown in our meta-analysis. Three studies contributed to the major heterogeneity of the RPC whole enface VD—Abri Aghdam et al [ 23 ], Pierro et al [ 32 ], and Song et al [ 34 ]. The I 2 measurement for this item significantly declined from 93% to 44% (chi 2 = 17.97, P = 0.06), after the removal of the above three studies.…”

“…The I 2 measurement for this item significantly declined from 93% to 44% (chi 2 = 17.97, P = 0.06), after the removal of the above three studies. In the acute-NAION subgroup, the heterogeneity also remarkably decreased from 96% to 46% (chi 2 = 5.58, P = 0.13), when the two studies were excluded [ 23 , 32 ]. Although these three studies were excluded from the analysis, the MDs for all were statistically significant.…”

“…There was only one study that reported RPC inside disc VD in the nonacute NAION subgroup; therefore, no heterogeneity was observed. The MDs were still significant after the removal of these two studies—Fard et al [ 19 ] and Pierro et al [ 32 ], but the sample numbers were relatively small within the groups. As to RPC peripapillary VD, two studies contributed majorly to the heterogeneity of this analysis—Mastropasqua et al [ 20 ] and Song et al [ 34 ].…”

Quantitative Optical Coherence Tomography Angiography Detects Retinal Perfusion Changes in Carotid Artery Stenosis

“…OCTA images provide accurate information regarding the perfusion status of intraretinal capillaries, and it is extremely sensitive in detecting retinal vascular alteration ( Arrigo et al, 2018 ; Battaglia Parodi et al, 2018 ; Parodi et al, 2018 ; Pierro et al, 2018 , 2019a , Pierro et al, 2019b ; Spaide et al, 2018 ; Pierro et al, 2020a ). The introduction of quantitative OCTA approaches is extremely useful in improving the detection of optic nerve head vascular network changes ( Pierro et al, 2020b ). To date, the retinal assessment in CAS setting was mainly confined to conventional angiography, which is invasive and prone to possible side effects.…”

An Integrated Approach to the Role of Neurosonology in the Diagnosis of Giant Cell Arteritis

“…The diagnostic work-up of AION benefits from the combined used of fluorescein angiography and noninvasive multimodal imaging, including CDI of the orbital vessels and structural Optical Coherence Tomography (OCT) of the optic nerve head (ONH) and OCT angiography [10,48]. They provide very detailed information regarding the structural (retinal nerve fiber layer-RNFLthickness/optic disc edema) and vascular impairments (microvascular defects-vessel tortuosity, and vessel density reduction) of the ONH, respectively [10,48].…”