Optical Coherence Tomography Changes in Central Nervous System Inflammatory Demyelinating Diseases: A Longitudinal...

Area of Science:

• Ophthalmology and Neurology
• Neuro-immunology and Neuro-imaging

Background:

• Optical coherence tomography (OCT) is a non-invasive imaging technique crucial for assessing neuroaxonal integrity in various optic nerve and retinal disorders.
• Recent advancements allow OCT to evaluate central nervous system inflammatory demyelinating diseases (CNS-IDDs), including clinically isolated syndrome (CIS), multiple sclerosis (MS) subtypes (RRMS, SPMS), neuromyelitis optica spectrum disorder (NMOSD), and MOGAD, which often impact the visual pathway.

Purpose of the Study:

• To longitudinally evaluate changes in OCT parameters and visual function across different CNS-IDD subgroups.
• To assess the potential of OCT as a biomarker for disease progression and phenotype differentiation in CNS-IDDs.

Main Methods:

• A retrospective cohort study involving 80 patients diagnosed with CNS-IDDs (CIS, RRMS, SPMS, NMOSD, MOGAD).
• Patients underwent serial OCT scans over 12 months to measure ganglion cell-inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (pRNFL) thickness.
• Visual acuity (VA) was assessed, and optic disc swelling was monitored; longitudinal and subgroup analyses were performed using repeated-measures GLM and Bonferroni-adjusted post hoc tests.

Main Results:

• All CNS-IDD subgroups exhibited a significant decline in VA and thinning of GCIPL and pRNFL over 12 months (p < 0.001).
• Neuromyelitis optica spectrum disorder (NMOSD) presented with the poorest baseline and longitudinal outcomes, while clinically isolated syndrome (CIS) showed relative preservation.
• Optic disc swelling increased significantly, particularly in SPMS, NMOSD, and MOGAD groups, with significant differences noted between subgroups (e.g., CIS vs. NMOSD, p < 0.001).

Conclusions:

• OCT demonstrates progressive neuroretinal degeneration across all CNS-IDD subgroups, confirming its role in monitoring disease activity.
• Significant differences in structural and functional outcomes were observed between subgroups, with NMOSD and SPMS showing the most severe degeneration.
• OCT serves as a sensitive, non-invasive, and reliable biomarker for tracking visual pathway changes and differentiating disease phenotypes in CNS demyelinating conditions.