Application of the international criteria for optic neuritis in the Acute Optic Neuritis Network

Abstract

International criteria; Optic neuritis; Acute optic neuritis network

Criterios internacionales; Neuritis óptica; Red de neuritis óptica aguda

Criteris internacionals; Neuritis òptica; Xarxa de neuritis òptica aguda

Objective The first international consensus criteria for optic neuritis (ICON) were published in 2022. We applied these criteria to a prospective, global observational study of acute optic neuritis (ON). Methods We included 160 patients with a first-ever acute ON suggestive of a demyelinating CNS disease from the Acute Optic Neuritis Network (ACON). We applied the 2022 ICON to all participants and subsequently adjusted the ICON by replacing a missing relative afferent pupillary defect (RAPD) or dyschromatopsia if magnetic resonance imaging pathology of the optical nerve plus optical coherence tomography abnormalities or certain biomarkers are present. Results According to the 2022 ICON, 80 (50%) patients were classified as definite ON, 12 (7%) patients were classified as possible ON, and 68 (43%) as not ON (NON). The main reasons for classification as NON were absent RAPD (52 patients, 76%) or dyschromatopsia (49 patients, 72%). Distribution of underlying ON etiologies was as follows: 78 (49%) patients had a single isolated ON, 41 (26%) patients were diagnosed with multiple sclerosis, 25 (16%) patients with myelin oligodendrocyte glycoprotein antibody-associated disease, and 15 (9%) with neuromyelitis optica spectrum disorder. The application of the adjusted ON criteria yielded a higher proportion of patients classified as ON (126 patients, 79%). Interpretation According to the 2022 ICON, almost half of the included patients in ACON did not fulfill the requirements for classification of definite or possible ON, particularly due to missing RAPD and dyschromatopsia. Thorough RAPD examination and formal color vision testing are critical to the application of the 2022 ICON.

First, the authors thank all ACON centers for their participation. Further, the authors would like to thank the administrative office of the Neuroscience Clinical Research Center (NCRC), funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy—EXC-2049—390688087 and Charité-BIH Clinical Study Center for their administrative support. Furthermore, ACON is partly funded by F. Hoffmann-La Roche as well as the Gesellschaft für Internationale Zusammenarbeit (GIZ). The funding sources had no role in study design, analysis of the data, or in writing of the manuscript. The authors thank all patients who participated in the study.