Thickness of the retinal nerve fibre layer (RNFL) correlates with the bicaudate ratio (BCR) and with subtypes of multiple sclerosis (MS), according to results from a study published in the Journal of Neuro-Ophthalmology. In addition, they concluded that OCT is better suited for assessment of MS than scanning laser polarimetry with variable corneal compensation (GDx VCC).
Researchers set out to determine the association between RNFL thickness and brain atrophy using MRI with BCR in patients with MS with differing levels of disease severity, and assessed the what correlations - if any - existed between RNFL thickness and Expanded Disability Status Scale (EDSS) scores.
In all, they included 88 patients with MS and 59 age- and sex-matched health controls. Of these, 11 had clinically isolated syndrome (CIS), 68 had relapsing-remitting MS (RR-MS), and 9 had secondary progressive MS. All were evaluated using OCT and GDx VCC, and the same brain MRI scanning protocol was used in all of them. Disability was evaluated using the EDSS and BCR was calculated by dividing the minimum intercaudate distance by brain width along the same level.
BCR was higher in patients with MS compared with controls (0.12 vs 0.08, respectively; P P = 0.002). Researchers found significant correlations between average RNFL thickness and EDSS (r = –0.43; P = 0.003), as well as correlations between BCR and GDx parameters in patients with MS without optic neuritis.
"We conclude that the damage of retinal axons appears to be related to brain damage in patients with MS," the authors wrote.
For more information on this study, view the abstract here.