There seems to be a difference in lesion location between the different subtypes of demyelinating optic neuritis, as detected by magnetic resonance imaging (MRI), especially during the acute phase of the disease, according to a literature review and meta-analysis published in Advances in Ophthalmology Practice and Research.
MRI can therefore be helpful for differentiating demyelinating optic neuritis subtypes, “combined with other ophthalmic examination results during an initial presentation of optic neuritis,” according to the authors.
MRI is commonly used to assess optic neuropathy and provide detailed information about lesions in the visual pathway. It can, therefore, help differentiate optic neuritis from other visual disorders.
Here, a team of researchers from China conducted a systemic review of the literature to see whether there is a difference in lesion location among different subtypes of demyelinating optic neuritis. The team included 55 studies from 8 electronic databases in their analysis and classified demyelinating optic neuritis into 5 subtypes.
They found that the abnormal rate of MRI examination was as high as 92% during the acute phase of demyelinating optic neuritis, which is within 4 weeks of the onset of symptoms. The lesions most frequently occurred in the orbital segment of the optic nerve. Optic tract involvement, on the other hand, was very rare.
In terms of demyelinating optic neuritis subtype, the orbital segment was more commonly involved in myelin oligodendrocyte glycoprotein antibody-related optic neuritis and chronic relapsing inflammatory optic neuropathy. In neuromyelitis optica spectrum disorder (NMOSD)-related optic neuritis, the lesions were usually in more posterior locations, in the intracranial segment, optic chiasm, or optic tract.
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Patients with myelin oligodendrocyte glycoprotein antibody-related optic neuritis had lesions involving more than half of the length of the optic nerve.
“In brief, we recommend conventional MRI for [demyelinating optic neuritis] patients in the acute phase,” the researchers wrote.
Wang Y, Fu J, Song H, Xu Q, Zhou H, Wei S. Differences in the involved sites among different types of demyelinating optic neuritis in traditional MRI examination: a systematic review and meta-analysis. Adv Ophthalmol Pract Res. Published online December 20, 2021. doi:10.1016/j.aopr.2021.100019