MOGAD Optic Neuritis Onset Characteristics
MOGAD optic neuritis develops subacutely over hours to days, not instantaneously—this distinguishes it from truly sudden vascular events like arterial occlusion. 1
Temporal Evolution Pattern
The visual impairment in MOGAD optic neuritis follows a characteristic subacute progression:
- Visual symptoms evolve over hours to days, with impairment worsening during the initial phase before stabilizing 1
- This subacute evolution is a key diagnostic feature that helps distinguish MOGAD optic neuritis from arteritic anterior ischemic optic neuropathy or retinal artery occlusion, which present with instantaneous vision loss 1
- Truly sudden causes of vision loss occur instantaneously, making the hours-to-days progression of MOGAD optic neuritis definitively subacute rather than sudden 1
Clinical Presentation Features
MOGAD optic neuritis has distinctive clinical characteristics at presentation:
- Profound reduced visual acuity with periocular pain that worsens with eye movement is typical 1, 2
- Prominent papilledema, papillitis, or optic disc swelling during acute episodes is common and more pronounced than in MS-related optic neuritis 3, 1, 2
- Bilateral simultaneous involvement occurs frequently and is a red flag distinguishing MOGAD from MS 3, 1, 2
Severity and Recovery Pattern
- Severe visual deficit or blindness in one or both eyes is characteristic, often more severe than typical MS-related optic neuritis 1
- Visual acuity typically recovers well with high-dose intravenous methylprednisolone, with most patients experiencing almost full recovery spontaneously or shortly after initiating acute treatment 4, 2
- A small fraction of patients with extensive optic nerve lesions involving the chiasm may experience irreversible severe visual impairment despite appropriate acute treatment 4
Important Clinical Pitfall
The subacute onset over hours to days is critical for diagnosis—if vision loss is truly instantaneous (occurring in seconds), consider vascular causes like retinal artery occlusion or arteritic anterior ischemic optic neuropathy instead 1. The temporal profile is one of the most important distinguishing features in the initial evaluation.