Choroidal Features of Acute Macular Neuroretinopathy via Optical Coherence Tomography Angiography and Correlation With Serial Multimodal Imaging

Abstract

IMPORTANCE Acute macular neuroretinopathy (AMN) is a rare, idiopathic condition resembling other acute maculopathies such as paracentral acute middle maculopathy. The pathophysiology of AMN is not well understood, and the role of the choroid in the pathogenesis of AMN remains controversial.OBJECTIVE To describe initial and serial multimodal imaging findings in AMN, with attention to choroidal vascular changes. DESIGN, SETTING, AND PARTICIPANTSRetrospective case series at a single institution, tertiary referral center. The case series included 7 patients with clinical diagnosis of AMN. MAIN OUTCOMES AND MEASURESMultimodal imaging findings, including fundus photography, fluorescein angiography, spectral-domain optical coherence tomography (OCT), en face near-infrared imaging, fundus autofluorescence, optical coherence tomography angiography (OCTA), and automated quantification of the regional structural context of choroidal flow interest between different imaging modalities, using an automatic algorithm.RESULTS Nine eyes from 7 patients (5 women and 2 men; mean age, 40.1 years) with a diagnosis of AMN were included. Mean duration of follow-up was 11 weeks (range, 1-25 weeks). All eyes had inner choroidal flow void on OCTA that topographically corresponded to regions of abnormal hyperreflectance of the outer retinal layers on spectral-domain OCT and hyporeflectance on en face near-infrared imaging (dice similarity coefficient, 0.76). For each patient, these areas of choroidal flow void on OCTA persisted during the follow-up period, while the abnormal hyperreflectance of outer plexiform layer and inner nuclear layer on spectral-domain OCT was observed to improve. CONCLUSIONS AND RELEVANCEThese findings suggest that areas of inner choroidal vascular flow void on OCTA are seen in patients with AMN. These areas may persist weeks after the onset of symptoms and suggest that vascular compromise of the inner choroid may be involved in the pathogenesis of AMN.

Acute macular neuroretinopathy: pathogenetic insights from optical coherence tomography angiography

“…However in support of the CC as the primary site of ischaemic insult, Lee et al 8 recently showed persistence of OCT-A choroidal flow void after resolution of the hyper-reflectivity of the outer retinal layers in seven patients with AMN.…”

“…OCT-A is able to assess the SCP traditionally seen on FA, and the DCP and CC without the use of a contrast agent8; thus, OCT-A offers a unique opportunity for understanding AMN pathogenesis.…”

Visualization of Mouse Choroidal and Retinal Vasculature Using Fluorescent Tomato Lectin Perfusion

“…[6][7][8][9][10] There are relatively robust methods for evaluating morphometric abnormalities of the choroid in humans using histology and fluorescent labeling of donor eyes that can discriminate between intact and ghost vessels 1,2,[11][12][13][14] as well as in vivo imaging techniques such as optical coherence tomography and optical coherence tomography angiography. [15][16][17] Such rapid and reliable methods for evaluating the choroid in mice are more challenging especially for whole mount, en face visualization. Current methods (most of which are compared in this article) to histologically visualize this critical structure using flat mounts in mice result in incomplete labeling of choroidal capillaries, have nonspecific staining, are outside the visible spectrum, or are highly time and/or resource consuming.…”

Projection-Resolved OCT Angiography of Microvascular Changes in Paracentral Acute Middle Maculopathy and Acute Macular Neuroretinopathy

“… 1 , 5 , 9 – 11 Similarly, AMN has been associated with occlusion of the DCP 4 , 12 or choriocapillaris. 13 , 14 The two major confounding factors in all these studies are projection artifacts cast from superficial blood vessels onto the deeper layers, and artifactual OCT signal attenuation underneath INL/ONL hyperreflective lesions. These issues are further complicated by accentuation of flow projection artifacts within OCT hyperreflective lesions.…”