Optical coherence tomography reflects brain atrophy in multiple sclerosis: A four-year study

Area of Science:

• Neuroscience
• Ophthalmology
• Radiology

Background:

• Multiple sclerosis (MS) is a demyelinating disease affecting the central nervous system.
• Optical coherence tomography (OCT) allows for in vivo imaging of retinal layers.
• Assessing retinal layer atrophy may provide insights into neurodegeneration in MS.

Purpose of the Study:

• To investigate the longitudinal association between retinal layer atrophy and brain substructure atrophy in MS patients.
• To validate the utility of OCT as a measure of neuronal damage in MS.
• To explore differences in these associations between relapsing-remitting MS (RRMS) and progressive MS (PMS).

Main Methods:

• 107 MS patients underwent biannual Cirrus HD-OCT and annual 3T MRI brain scans over a median of 46 months.
• Automated macular segmentation was used for retinal layer thickness measurements.
• Linear regression estimated individual rates of change, which were then correlated, adjusting for covariates.

Main Results:

• Rates of ganglion cell + inner plexiform layer (GCIP) atrophy were significantly associated with whole-brain, gray matter (GM), white matter (WM), and thalamic atrophy.
• These associations were stronger in progressive MS (PMS) compared to relapsing-remitting MS (RRMS).
• In RRMS, GCIP atrophy correlated with lesion accumulation, and refined analyses excluding optic neuritis effects strengthened the GCIP-brain atrophy correlations.

Conclusions:

• Longitudinal GCIP atrophy in MS patients reflects whole-brain and GM atrophy, particularly in PMS.
• OCT measurements of GCIP layer thickness can serve as a valuable indicator of neurodegenerative changes in MS.
• Findings support the use of OCT for clinical monitoring and as an outcome measure in MS clinical trials.