Using retinal architecture to help characterize multiple sclerosis patients

Objective: We compared retinal nerve fibre layer (RNFL) thickness and visual function in a heterogeneous multiple sclerosis (MS) cohort to determine whether optical coherence tomography (OCT) may complement the existing methods used to characterize MS patients. Design: Cross-sectional cohort study. Participants: One hundred and ninety-three patients with optic neuritis (ON) as a clinically isolated syndrome (CIS) (n = 63), relapsing-remitting MS (RRMS) (n = 108), secondary progressive MS (SPMS) (n = 13), and primary progressive MS (PPMS) (n = 9). Methods: All patients underwent standardized ophthalmic, neurological, and OCT testing at a single academic institution. Results: RNFL values were reduced in PPMS (94.3 mu m), RRMS (99.6 mu m), and SPMS eyes (84.7 mu m) relative to CIS eyes (105.7 mu m) (p < 0.0001). RNFL values were lower in eyes with recurrent ON (64.2 mu m) relative to eyes affected by a single ON event (86.3 mu m) (p < 0.0001). The strongest correlation between RNFL thickness and neurological disability occurred in RRMS patients (r = -0.51, p < 0.0001). RNFL thickness correlated with visual field sensitivity for CIS (r = 0.23, p < 0.01) and RRMS (r = 0.22, p < 0.01) patients. Simple linear regression showed that every 10 pm decrease in RNFL correlated with a 5.8 decibel decrease in visual field sensitivity (adjusted R(2) = 0.35, p < 0.0001) for RNFL values less than 75 mu m. Conclusions: There were robust correlations between RNFL thickness and visual function, particularly in ON eyes. OCT may complement the existing tools used to characterize MS patients, but further studies are needed.