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Spectrum Library

Astrocytic outer retinal layer thinning is not a feature in AQP4-IgG seropositive neuromyelitis optica spectrum disorders

Angelo Lu, Hanna G Zimmermann, Svenja Specovius, Seyedamirhosein Motamedi, Claudia Chien, Charlotte Bereuter, Marco A Lana-Peixoto, Mariana Andrade Fontenelle, Fereshteh Ashtari, Rahele Kafieh, Alireza Dehghani, Mohsen Pourazizi, Lekha Pandit, Anitha D’Cunha, Ho Jin Kim, Jae-Won Hyun, Su-Kyung Jung, Letizia Leocani, Marco Pisa, Marta Radaelli, Sasitorn Siritho, Eugene F May, Caryl Tongco, Jérôme De Sèze, Thomas Senger, Jacqueline Palace, Adriana Roca-Fernández, Maria Isabel Leite, Srilakshmi M Sharma, Hadas Stiebel-Kalish, Nasrin Asgari, Kerstin Kathrine Soelberg, Elena H Martinez-Lapiscina, Joachim Havla, Yang Mao-Draayer, Zoe Rimler, Allyson Reid, Romain Marignier, Alvaro Cobo-Calvo, Ayse Altintas, Uygur Tanriverdi, Rengin Yildirim, Orhan Aktas, Marius Ringelstein, Philipp Albrecht, Ivan Maynart Tavares, Denis Bernardi Bichuetti, Anu Jacob, Saif Huda, Ibis Soto de Castillo, Axel Petzold, Ari J Green, Michael R Yeaman, Terry J Smith, Lawrence Cook, Friedemann Paul, Alexander U Brandt, Frederike Cosima Oertel, GJCF International Clinical Consortium for NMOSD
Correspondence to Professor Friedemann Paul, Experimental and Clinical Research Center, Charité Universitätsmedizin Berlin, 10117 Berlin, Germany; friedemann.paul@charite.de

Abstract

Background: Patients with anti-aquaporin-4 antibody seropositive (AQP4-IgG+) neuromyelitis optica spectrum disorders (NMOSDs) frequently suffer from optic neuritis (ON) leading to severe retinal neuroaxonal damage. Further, the relationship of this retinal damage to a primary astrocytopathy in NMOSD is uncertain. Primary astrocytopathy has been suggested to cause ON-independent retinal damage and contribute to changes particularly in the outer plexiform layer (OPL) and outer nuclear layer (ONL), as reported in some earlier studies. However, these were limited in their sample size and contradictory as to the localisation. This study assesses outer retinal layer changes using optical coherence tomography (OCT) in a multicentre cross-sectional cohort.

Method: 197 patients who were AQP4-IgG+ and 32 myelin-oligodendrocyte-glycoprotein antibody seropositive (MOG-IgG+) patients were enrolled in this study along with 75 healthy controls. Participants underwent neurological examination and OCT with central postprocessing conducted at a single site.

Results: No significant thinning of OPL (25.02±2.03 µm) or ONL (61.63±7.04 µm) were observed in patients who were AQP4-IgG+ compared with patients who were MOG-IgG+ with comparable neuroaxonal damage (OPL: 25.10±2.00 µm; ONL: 64.71±7.87 µm) or healthy controls (OPL: 24.58±1.64 µm; ONL: 63.59±5.78 µm). Eyes of patients who were AQP4-IgG+ (19.84±5.09 µm, p=0.027) and MOG-IgG+ (19.82±4.78 µm, p=0.004) with a history of ON showed parafoveal OPL thinning compared with healthy controls (20.99±5.14 µm); this was not observed elsewhere.

Conclusion: The results suggest that outer retinal layer loss is not a consistent component of retinal astrocytic damage in AQP4-IgG+ NMOSD. Longitudinal studies are necessary to determine if OPL and ONL are damaged in late disease due to retrograde trans-synaptic axonal degeneration and whether outer retinal dysfunction occurs despite any measurable structural correlates.