Cloudy Vision in NMOSD
Yes, cloudy vision can be a manifestation of NMOSD, though it is not the most characteristic visual symptom. The typical visual presentation in NMOSD is severe optic neuritis with profound visual loss, often bilateral and simultaneous, rather than the "cloudy" or blurred vision more commonly associated with MS-related optic neuritis 1, 2.
Characteristic Visual Symptoms in NMOSD
The visual manifestations of NMOSD optic neuritis are typically more severe and extensive than what patients might describe as simple "cloudy vision":
- Severe visual deficit or blindness in one or both eyes is the hallmark presentation, often more profound than typical MS-related optic neuritis 2
- Bilateral simultaneous involvement is a red flag feature that distinguishes NMOSD from MS, where sequential involvement is more common 1, 2
- Periocular pain worsening with eye movement accompanies the visual loss 2
- Red-green color desaturation (dyschromatopsia) is characteristic, similar to other forms of optic neuritis 2
Imaging Features That Distinguish NMOSD Visual Pathway Involvement
When patients present with visual symptoms concerning for NMOSD, specific MRI findings help confirm the diagnosis:
- Long optic nerve lesions extending over >50% of the optic nerve length or involving the optic chiasm are highly suggestive of NMOSD 1, 2
- "Cloud-like" enhancement pattern on MRI is a distinctive feature of NMOSD that is poorly marginated and distinct from the typical nodular or ring enhancement seen in MS 3, 2
- Posterior optic nerve involvement extending to the chiasm is highly suggestive of AQP4-IgG-seropositive NMOSD 1, 2
- Perioptic gadolinium enhancement (optic nerve sheath involvement) during acute episodes is characteristic 2
Critical Diagnostic Pitfalls
- Do not dismiss "cloudy vision" as benign if accompanied by pain with eye movement, color desaturation, or rapid progression over hours to days 2
- Bilateral simultaneous presentation should immediately trigger testing for AQP4-IgG and MOG-IgG antibodies, as this is atypical for MS 1, 4
- Prominent papilledema or optic disc swelling during acute episodes suggests NMOSD rather than typical MS optic neuritis 2
- Visual symptoms evolving over hours to days (subacute onset) distinguish optic neuritis from vascular events, which occur instantaneously 2
Prognostic Implications
The severity of visual involvement in NMOSD has important prognostic implications:
- Optic nerve lesion length at the acute phase predicts long-term retinal neuro-axonal loss and chronic visual impairment 5
- Untreated NMOSD leads to approximately 50% of patients becoming wheelchair users and blind within 5 years 6
- Earlier aggressive treatment with high-dose intravenous corticosteroids followed by plasma exchange for steroid-refractory cases is critical to prevent permanent visual disability 4, 6