Assessment of macular volume, retinal nerve fiber layer thickness, and choroidal thickness using spectral domain optical coherence tomography in individuals with multiple sclerosis

PURPOSE: This investigation aimed to assess structural alterations in the retina and choroid among individuals with multiple sclerosis (MS), both with and without prior optic neuritis (ON), using spectral domain-optical coherence tomography (SD-OCT) and enhanced depth imaging-optical coherence tomography (EDI-OCT).
METHODS: In this cross-sectional analysis, participants included patients with relapsing-remitting MS and matched healthy individuals. MS subjects were stratified into ON and non-ON categories. Measurements of retinal nerve fiber layer (RNFL) thickness, macular volume (MV), and choroidal thickness (CT) were conducted and examined in relation to Expanded Disability Status Scale (EDSS) scores and the duration of disease.
RESULTS: Data from 80 individuals (40 MS, 40 controls) were analyzed. RNFL thickness was significantly reduced in the MS group, particularly in the temporal and superior regions (p<0.001 and p=0.004, respectively), with ON patients showing more marked thinning temporally (p=0.01). No notable differences were observed in MV or CT at any location (subfoveal, nasal, and temporal) (p>0.05). A significant inverse association existed between EDSS and RNFL thickness in superior (r=−0.768), temporal (r=−0.501), and nasal (r=−0.276) quadrants. Duration of illness showed a negative correlation with inferior RNFL (r=−0.631) and nasal/temporal CT (r=−0.351; r=−0.271).
CONCLUSION: Thinning of the RNFL – especially in the temporal and superior regions – was a consistent finding and was linked to both disease severity and chronicity. Conversely, MV and CT parameters did not show substantial variation, implying RNFL thickness could serve as a more sensitive biomarker for MS-related neurodegeneration.

Keywords: Multiple sclerosis, optic neuritis, optical coherence tomography, retinal nerve fiber layer.