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 µm), RRMS (99.6 µm), and SPMS eyes (84.7 µm) relative to CIS eyes (105.7 µm) (p<0.0001). RNFL values were lower in eyes with recurrent ON (64.2 µm) relative to eyes affected by a single ON event (86.3 µm) (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 µm decrease in RNFL correlated with a 5.8 decibel decrease in visual field sensitivity (adjusted R2 = 0.35, p < 0.0001) for RNFL values less than 75 µm.

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.