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New definitions for an old disease: the newly proposed diagnostic criteria for Optic Neuritis Comment on: Diagnosis and classification of optic neuritis.

Newly proposed diagnostic criteria for optic neuritis renovate the clinical and research scenario and facilitate patients’ management

Early recognition of optic neuritis(ON) is crucial to enhance diagnostic accuracy, initiate appropriate treatment and improve visual outcomes1. Nevertheless, misdiagnosis remains a significant concern2. Considering the relevant advances in the field of neuroinflammatory disorders, Petzold et al. revised the definition of ON and provided a consensus view on the diagnosis and classification of this condition3.
The authors propose a two-level diagnostic classification. The first one entails the distinction of autoimmune causes (often relapsing) from infectious/systemic causes. The second level includes specific diagnosis and combines an anatomical compartment model and immunological biomarkers with chronological clinical features, OCT and MRI findings. In addition, the authors provided a chronological classification that distinguishes acute, subacute, relapsing and chronic ON. As a novelty the concept of “primary progressive ON” is introduced, referring to a rare condition that can occur in patients with secondary progressive multiple sclerosis. However, this definition is still debated, and further research is needed for its use to become established.
According to the novel criteria clinical assessment is paramount, and a diagnosis of possible ON can be made on clinical grounds alone when the full clinical picture of a monocular, subacute loss of vision associated with orbital pain, dyschromatopsia, and relative afferent pupillary deficit (RAPD) is detected. The diagnosis of definite optic neuritis requires in addition one positive paraclinical test.
This will speed up initial decision-making, as paraclinical tests take time or may not be available in low-income countries.
This paper lays the foundations for a more precise characterization of optic neuritis according to chronological and anatomical classifications, which will be useful both in the clinical and research setting.

Key Points:

  • A 2 level diagnostic classification for ON is proposed, distinguishing specific etiologies and combining an anatomical compartment model and immunological biomarkers with chronological clinical features, OCT findings, and MRI findings
  • An additional chronological classification that distinguishes acute, subacute, relapsing, and chronic ON is provided
  • According to the new criteria, the diagnosis of “possible” ON can be made solely on clinical grounds allowing to speed up the process
  • The role of paraclinical assessments remains crucial for precise etiological definition and to improve diagnostic accuracy.
  • These criteria are designed to improve the diagnosis of ON in clinical practice, and to provide useful definitions in the research setting.


  1. Bennett JL, Costello F, Chen JJ, et al. Optic neuritis and autoimmune optic neuropathies: advances in diagnosis and treatment. Lancet Neurol. 2023;22(1):89-100. doi:10.1016/S1474-4422(22)00187-9
  2. Stunkel L, Kung NH, Wilson B, McClelland CM, Van Stavern GP. Incidence and Causes of Overdiagnosis of Optic Neuritis. JAMA Ophthalmol. 2018;136(1):76-81. doi:10.1001/jamaophthalmol.2017.5470
  3. Petzold A, Fraser CL, Abegg M, et al. Diagnosis and classification of optic neuritis. Lancet Neurol. 2022;21(12):1120-1134. doi:10.1016/S1474-4422(22)00200-9

Giacomo Greco, IRCCS Mondino Foundation

Publish on behalf of the Scientific Panel on Neuroimmunology