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

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 Participants: Retrospective case series at a single institution, tertiary referral center. The case series included 7 patients with clinical diagnosis of AMN.

Main Outcomes and Measures: Multimodal 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 Relevance: These 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.