Reduced retinal nerve fiber layer and macular thickness in patients with multiple sclerosis with no history of optic neuritis identified by the use of spectral domain high-definition optical coherence tomography

Multiple sclerosis (MS) is a chronic immune-mediated disease of the central nervous system (CNS), with both inflammatory and degenerative components. The visual system is frequently involved, often in the form of visual loss from optic neuritis (ON). Retinal nerve fiber layer (RNFL) loss has been demonstrated in individuals with MS, not only in those with previous ON but also in absence of historical evidence of previous acute inflammation/demyelination of the optic nerve. Peripapillary RNFL measurements of all quadrants, central macular thickness, and average macular thickness were performed in 32 eyes of healthy volunteers and 60 eyes of individuals with a diagnosis of relapsing remitting MS using high definition spectral domain optical coherence tomography (HD-OCT). Both the Macular Cube 512 × 128 scan and RNFL measurement by the Optic Disc Cube 200 × 200 protocol were performed on all eyes. Eyes of individuals with MS with no previous ON had significantly decreased overall RNFL thickness (89.1 μm) compared to controls (98.0 μm) (p < 0.05). MS mainly affected the temporal quadrant (56.6 μm versus [vs.] 67.8 μm) (p < 0.05), and inferior quadrant (117.9 μm vs. 132.1 μm) (p < 0.05), respectively. Also, the patients with MS demonstrated significantly decreased average macular thickness (280 μm) compared to the control group (287 μm) (p < 0.05). A significant correlation between RNFL and average macular thickness was also found in eyes of patients with MS (r = 0.69, p < 0.01). HD-OCT is a quick, inexpensive and promising tool to detect subclinical changes in RNFL and macular thickness in individuals with MS. Longitudinal studies should be encouraged to examine disease progression over time in individuals with MS.