{
  "abstract": "Objectives Acute anterior ischaemic optic neuropathy (AION) is a feared ischaemic complication of giant cell arteritis (GCA). However, distinguishing arteritic AION (A-AION) from its non-arteritic counterpart (NA-AION), which accounts for approximately 90% of cases, can be challenging. Rapid initiation of glucocorticoids is essential to prevent irreversible vision loss in GCA but is unnecessary in NA-AION. This study evaluated the use of orbital MRI in differentiating A-AION from NA-AION.Methods In this prospective single-centre study, patients >50 years who had recent-onset AION were enrolled between June 2021 and October 2024. The final diagnosis of GCA was confirmed after comprehensive assessments and ≥6 months follow-up. Orbital MRIs were independently evaluated by two experienced radiologists blinded to the clinical diagnosis.Results Of the 18 patients analysed, nine had A-AION (two with bilateral involvement), while nine had NA-AION. MRI demonstrated differences between the groups, notably in contrast enhancement of the ophthalmic artery (72.7% vs 22.2%; p=0.07), perineural fat (90.9% vs 22.2%; p=0.005) and retrobulbar fat (100% vs 11.1%; p<0.001). The most discriminative MRI feature was retrobulbar fat enhancement, achieving 100% (95% CI 72 to 100) sensitivity and 89% (95% CI 52 to 100) specificity. Bilateral orbital enhancement was identified in more than half of the unaffected contralateral eyes in A-AION patients.Conclusion These results suggest that orbital MRI may help clinicians rapidly differentiate between A-AION and NA-AION to provide the most appropriate treatment.",
  "authors": [
    {
      "affiliations": [
        "Department of Internal Medicine and Clinical Immunology, Referral Center for Rare Systemic Autoimmune and Autoinflammatory Diseases, Dijon-Bourgogne University Hospital, University EPE Bourgogne Europe, Dijon, France"
      ],
      "name": "Guillaume Brenac"
    },
    {
      "affiliations": [
        "Department of Radiology, Dijon-Bourgogne University Hospital, University EPE Bourgogne Europe, Dijon, France"
      ],
      "name": "Angélique Bernard"
    },
    {
      "affiliations": [
        "Department of Radiology, Dijon-Bourgogne University Hospital, University EPE Bourgogne Europe, Dijon, France"
      ],
      "name": "Brivael Lemogne"
    },
    {
      "affiliations": [
        "Department of Internal Medicine and Clinical Immunology, Referral Center for Rare Systemic Autoimmune and Autoinflammatory Diseases, Dijon-Bourgogne University Hospital, University EPE Bourgogne Europe, Dijon, France",
        "Department of Vascular Medicine, Dijon-Bourgogne University Hospital, University EPE Bourgogne Europe, Dijon, France"
      ],
      "name": "Hélène Greigert"
    },
    {
      "affiliations": [
        "Department of Rheumatology, Dijon-Bourgogne University Hospital, University EPE Bourgogne Europe, Dijon, France"
      ],
      "name": "André Ramon"
    },
    {
      "affiliations": [
        "Department of Internal Medicine and Clinical Immunology, Referral Center for Rare Systemic Autoimmune and Autoinflammatory Diseases, Dijon-Bourgogne University Hospital, University EPE Bourgogne Europe, Dijon, France"
      ],
      "name": "Sylvain Audia"
    },
    {
      "affiliations": [
        "Department of Internal Medicine and Clinical Immunology, Referral Center for Rare Systemic Autoimmune and Autoinflammatory Diseases, Dijon-Bourgogne University Hospital, University EPE Bourgogne Europe, Dijon, France"
      ],
      "name": "Vanessa Leguy-Seguin"
    },
    {
      "affiliations": [
        "Department of Internal Medicine and Clinical Immunology, Referral Center for Rare Systemic Autoimmune and Autoinflammatory Diseases, Dijon-Bourgogne University Hospital, University EPE Bourgogne Europe, Dijon, France"
      ],
      "name": "Jérôme Razanamahery"
    },
    {
      "affiliations": [
        "Department of Radiology, Dijon-Bourgogne University Hospital, University EPE Bourgogne Europe, Dijon, France"
      ],
      "name": "Pierre-Olivier Comby"
    },
    {
      "affiliations": [
        "Department of Ophthalmology, Dijon-Bourgogne University Hospital, University EPE Bourgogne Europe, Dijon, France"
      ],
      "name": "Louis Arnould"
    },
    {
      "affiliations": [
        "Department of Ophthalmology, Dijon-Bourgogne University Hospital, University EPE Bourgogne Europe, Dijon, France"
      ],
      "name": "Pierre-Henry Gabrielle"
    },
    {
      "affiliations": [
        "Department of Ophthalmology, Dijon-Bourgogne University Hospital, University EPE Bourgogne Europe, Dijon, France"
      ],
      "name": "Catherine Creuzot-Garcher"
    },
    {
      "affiliations": [
        "Department of Internal Medicine and Clinical Immunology, Referral Center for Rare Systemic Autoimmune and Autoinflammatory Diseases, Dijon-Bourgogne University Hospital, University EPE Bourgogne Europe, Dijon, France"
      ],
      "name": "Bernard Bonnotte"
    },
    {
      "affiliations": [
        "Department of Internal Medicine and Clinical Immunology, Referral Center for Rare Systemic Autoimmune and Autoinflammatory Diseases, Dijon-Bourgogne University Hospital, University EPE Bourgogne Europe, Dijon, France"
      ],
      "name": "Maxime Samson"
    }
  ],
  "title": "Orbital MRI for diagnosing giant cell arteritis in cases of anterior ischaemic optic neuropathy",
  "uid": "5c0d2760-1be7-55fc-907e-93d5303b28ca"
}