Assessing structure and function of the afferent visual pathway in multiple sclerosis and associated optic neuritis

Area of Science:

• Neuroscience
• Ophthalmology
• Radiology

Background:

• Multiple sclerosis (MS) frequently affects the afferent visual pathway.
• Assessing visual pathway involvement offers insights into MS pathophysiology and therapeutic strategies.

Purpose of the Study:

• To review current clinical, imaging, and electrophysiological assessment methods for the visual pathway in MS.
• To highlight the role of advanced imaging techniques in evaluating MS-related visual dysfunction.

Main Methods:

• Optical coherence tomography, scanning laser polarimetry, and confocal scanning laser ophthalmoscopy quantify retinal nerve fibre layer (RNFL) thickness.
• MRI techniques including T2-weighted imaging, gadolinium enhancement, magnetization transfer ratio (MTR), and diffusion tensor imaging (DTI) assess optic nerve and white matter integrity.
• Functional MRI evaluates cortical reorganisation, while visual evoked potentials detect demyelination-induced conduction delays.

Main Results:

• Reduced RNFL thickness is a common finding after optic neuritis.
• MRI reveals lesions, axonal loss, and myelination status in the optic nerve.
• DTI assesses white matter tract integrity, and fMRI monitors cortical changes.
• Functional tests provide detailed visual performance data.

Conclusions:

• Investigative methods have significantly advanced understanding of MS and optic neuritis pathophysiology.
• These techniques are crucial for monitoring disease progression and evaluating therapeutic interventions.