Optimal intereye difference thresholds by optical coherence tomography in multiple sclerosis: An international study

Objective: To determine the optimal thresholds for intereye differences in retinal nerve fiberand ganglion cell + inner plexiform layerthicknesses for identifying unilateral optic nervelesions in multiple sclerosis. Current international diagnostic criteria for multiple sclerosisdo not include the optic nerveas a lesion site despite frequent involvement. Optical coherence tomographydetects retinal thinning associated with optic nervelesions. Methods: In this multicenter international study at 11 sites, optical coherence tomographywas measured for patients and healthy controls as part of the International Multiple Sclerosis Visual SystemConsortium. High- and low-contrast acuity were also collected in a subset of participants. Presence of an optic nervelesion for this study was defined as history of acute unilateral optic neuritis. Results: Among patients (n = 1,530), receiver operating characteristic curve analysis demonstrated an optimal peripapillary retinal nerve fiber layerintereye difference threshold of 5μm and ganglion cell + inner plexiform layerthreshold of 4μm for identifying unilateral optic neuritis(n = 477). Greater intereye differences in acuities were associated with greater intereye retinal layer thickness differences (p ≤ 0.001). Interpretation: Intereye differences of 5μm for retinal nerve fiber layerand 4μm for macular ganglion cell + inner plexiform layerare robust thresholds for identifying unilateral optic nervelesions. These thresholds may be useful in establishing the presence of asymptomatic and symptomatic optic nervelesions in multiple sclerosisand could be useful in a new version of the diagnostic criteria. Our findings lend further validation for utilizing the visual systemin a multiple sclerosisclinical trial setting. Ann Neurol 2019;85:618–629.