A three-year longitudinal study of retinal function and structure in patients with multiple sclerosis

Area of Science:

• Ophthalmology
• Neuroscience
• Immunology

Background:

• Multiple sclerosis (MS) can affect the retina beyond optic neuritis (ON).
• Electroretinogram (ERG) and optical coherence tomography (OCT) reveal retinal changes in MS patients, irrespective of ON history.
• Previous studies on ERG and OCT in MS provided only cross-sectional data.

Purpose of the Study:

• To longitudinally assess electroretinogram (ERG) and optical coherence tomography (OCT) in multiple sclerosis (MS) patients over 3 years.
• To investigate the impact of changes in MS-related disability and non-ON relapses on ERG and OCT measures.
• To explore associations between OCT parameters and corresponding ERG parameters.

Main Methods:

• A 3-year longitudinal observational substudy involving 23 MS patients.
• Annual assessments of ERG (peak times, b-wave amplitude) and OCT (retinal nerve fibre layer thickness, retinal layer volumes).
• Generalized estimating equation models were used to analyze changes in ERG and OCT, accounting for disability, relapses, age, and treatment status.

Main Results:

• ERG peak times showed minor fluctuations, while OCT values remained stable over the 3-year study period.
• Increased patient disability correlated with prolonged mixed rod-cone ERG b-wave peak times.
• No significant associations were found between OCT parameters and ERG parameters.

Conclusions:

• Retinal bipolar cell function in MS patients may be influenced by disability progression.
• Recent non-ON MS relapses did not appear to impact ERG or OCT results.
• Longitudinal studies of retinal function in MS may require extended observation periods due to potentially small and clinically uncertain ERG changes over 3 years.