RT Journal Article SR Electronic T1 MRI signs helpful in the differentiation of patients with anterior ischaemic optic neuropathy and optic neuritis JF British Journal of Ophthalmology JO Br J Ophthalmol FD BMJ Publishing Group Ltd. SP 121 OP 126 DO 10.1136/bjophthalmol-2021-319537 VO 107 IS 1 A1 Petroulia, Valentina Daphne A1 Brügger, Dominik A1 Hoepner, Robert A1 Vicini, Rino A1 Winklehner, Anna A1 Abegg, Mathias A1 Wagner, Franca YR 2023 UL http://bjo.bmj.com/content/107/1/121.abstract AB Background/Aims The aim of this study was to identify specific MRI characteristics of anterior ischaemic optic neuropathy (AION) and optic neuritis (ON) that would aid in the differentiation between these two diagnoses.Methods We retrospectively analysed a consecutive case series including all patients with an MRI study of brain and orbit and the clinical diagnosis of either ON or AION. We examined the scans for restricted diffusion of the optic nerve, optic sheath diameter, enhancement and location of enhancement of the optic nerve and distribution of the white matter lesions.Results Fifty patients met the inclusion criteria. We found an accuracy of 0.98 for the discrimination between AION and ON based solely on parameters extracted from MRI data. Dominance analysis to determine the most influential parameters showed that the enhancement pattern of the optic nerve and distribution of the white matter lesions had the biggest impact on the classification and led to a discrimination accuracy of 0.9 when used alone.Conclusion In patients with an inconclusive clinical diagnosis, optic nerve enhancement pattern and distribution of white matter lesions can aid in the diagnosis and differentiation between AION and ON. Diffusion-weighted imaging did not add significant information to the diagnosis or help to differentiate between the two conditions.All data relevant to the study are included in the article or uploaded as supplemental information.