Outer Retinal Layer Assessment in Patients with Relapsing-Remitting Multiple Sclerosis: Multifocal Field...

Area of Science:

• Ophthalmology
• Neuroscience
• Multiple Sclerosis Research

Background:

• Relapsing remitting multiple sclerosis (RRMS) is associated with central nervous system atrophy.
• Primary retinopathy may occur in RRMS, reflecting this atrophy.
• The outer retinal layers' involvement in RRMS, with or without optic neuritis (ON), requires further investigation.

Purpose of the Study:

• To assess outer retinal layers in RRMS patients using multifocal electroretinography (mf-ERG) and spectral-domain optical coherence tomography (OCT).
• To compare functional and structural parameters between RRMS patients with and without ON, and with healthy controls.

Main Methods:

• A case-control study involving 30 RRMS patients (with and without ON) and 30 age/sex-matched healthy controls.
• Functional assessment using mf-ERG to measure retinal electrical responses.
• Structural assessment using OCT to measure outer retinal layer thickness.

Main Results:

• RRMS patients (with and without ON) exhibited significantly reduced amplitudes and delayed peak times in mf-ERG compared to controls.
• Outer and inner retinal thickness were significantly decreased in RRMS patients compared to controls.
• Most mf-ERG parameters and retinal thickness showed no significant difference between RRMS patients with and without ON, except for specific parameters in R2 and R3.

Conclusions:

• Functional and structural alterations in the outer retina (bipolar and photoreceptor cells) are present in RRMS, irrespective of ON.
• The outer retina may be a primary site of pathology in MS, not solely secondary to optic nerve damage.