Clinical and Diagnostic Findings of Acute Macular Neuroretinopathy and Paracentral Acute Middle Maculopathy in the COVID-19 Era

Introduction: Growing evidence suggest an association between the infection from the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and eye disorders. The aim of this review is to analyze the clinical presentation and diagnostic features of acute macular neuroretinopathy (AMN) and paracentral acute middle maculopathy (PAMM) associated with COVID-19 infection. The features are then compared with previous reports regarding these retinal disorders, to recognize possible specific characteristics and to assess the role of multimodal ophthalmic imaging. Methods: A literature search was performed by consulting PubMed, Scopus and Embase. The following terms were searched: "(COVID-19 OR SARS-CoV-2 OR coronavirus) AND ((acute macular neuroretinopathy) OR (paracentral acute middle maculopathy))". Inclusion criteria were as follow: 1) publication date from January 31st, 2020 to January 31st, 2022; 2) English language; 3) original research or case report; 4) free full-text availability. Results: Optical coherence tomography (OCT) findings in AMN patients were hyper-reflectivity (HR) of the outer plexiform layer (OPL), of the outer nuclear layer (ONL), and ellipsoid or interdigitate zones (EZ and IZ, respectively) disruption. In most cases, the presence of HR and EZ/IZ abnormalities resulted combined. When performed, OCT angiography (OCTA) identified attenuation of signal of the deep capillary plexus (DCP). The most common OCT finding in PAMM was an alteration of the inner nuclear layer (INL), associated with other areas of HR, while no signs of EZ/IZ disruption were detected. When performed, OCT-A showed the attenuation of signal of both the DCP, and the superficial capillary plexus (SCP) Discussione/Conclusion: In this review we reported a case series of AMN and PAMM in patients with a previous or concomitant infection from SARS-CoV-2. The microvascular changes in these cases are highlighted by the OCTA scans. Even if we are far from the determination of a direct link between COVID-19 and these retinal disorders, we could hypothesize that the vascular alterations associated with Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) infection could be a possible risk factor for both AMN and PAMM.