Pattern VEP in two immunochemical subtypes of optic neuritis

Area of Science:

• Neuroscience
• Ophthalmology
• Immunology

Background:

• Optic neuritis (ON) is an inflammatory condition of the optic nerve.
• Cerebrospinal fluid (CSF) analysis, specifically for oligoclonal IgG bands, can help stratify ON patients.
• The presence of oligoclonal IgG in CSF is associated with an increased risk of developing multiple sclerosis (MS).

Purpose of the Study:

• To compare visual functions and visual evoked potentials (VEP) in patients with optic neuritis based on CSF oligoclonal IgG status.
• To investigate the long-term neurological outcomes, particularly MS development, in these patient groups.
• To explore the relationship between VEP changes, color vision deficits, and the underlying cause of optic nerve inflammation.

Main Methods:

• Two groups of optic neuritis patients were studied: ON (+) with CSF oligoclonal IgG and ON (-) without.
• Visual functions including visual acuity, visual fields, and color vision were assessed.
• Pattern visual evoked potentials (VEP) were recorded to evaluate optic nerve pathway function.
• Long-term follow-up was conducted to monitor for the development of neurological diseases like MS.

Main Results:

• While initial visual recovery (acuity, fields) was similar, the ON (-) group showed better recovery in color vision and pattern VEP compared to the ON (+) group.
• A significant majority of ON (+) patients developed multiple sclerosis, whereas only one patient in the ON (-) group did.
• A stronger correlation between color vision defects and VEP latency changes was observed in the ON (+) group.

Conclusions:

• The presence of oligoclonal IgG in CSF of optic neuritis patients is a strong predictor for developing multiple sclerosis.
• Demyelinating disease is a more likely cause of optic nerve inflammation in patients with CSF oligoclonal IgG.
• While visual acuity and fields recover similarly, subtle visual functions like color vision and pattern VEP are more affected in patients with a higher risk of MS.