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 fiber and ganglion cell + inner plexiform layer thicknesses for identifying unilateral optic nerve lesions in multiple sclerosis. Current international diagnostic criteria for multiple sclerosis do not include the optic nerve as a lesion site despite frequent involvement. Optical coherence tomography detects retinal thinning associated with optic nerve lesions. METHODS: In this multicenter international study at 11 sites, optical coherence tomography was measured for patients and healthy controls as part of the International Multiple Sclerosis Visual System Consortium. High- and low-contrast acuity were also collected in a subset of participants. Presence of an optic nerve lesion 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 layer intereye difference threshold of 5µm and ganglion cell + inner plexiform layer threshold 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 layer and 4µm for macular ganglion cell + inner plexiform layer are robust thresholds for identifying unilateral optic nerve lesions. These thresholds may be useful in establishing the presence of asymptomatic and symptomatic optic nerve lesions in multiple sclerosis and could be useful in a new version of the diagnostic criteria. Our findings lend further validation for utilizing the visual system in a multiple sclerosis clinical trial setting. Ann Neurol 2019;85:618-629.

Predictors of retinal atrophy in multiple sclerosis: A longitudinal study using spectral domain optical coherence tomography with segmentation analysis.

BACKGROUND: Multiple sclerosis is an inflammatory demyelinating disease characterized by progressive axonal loss affecting mainly the inner retinal layers. Optical coherence tomography (OCT) provides in-vivo quantification of the retinal layers and allows measuring progressive retinal changes. Our objective was to assess the longitudinal changes in the retina using spectral domain OCT (SDOCT) and to identify independent predictors affecting retinal thinning in MS patients. METHODS: A prospective study in a tertiary care MS center was conducted to study the longitudinal retinal changes in MS patients. All subjects underwent baseline and follow up OCT assessment with segmentation analysis. Regression analysis was performed to assess clinical factors (age, sex, disease duration, history of optic neuritis before baseline, non-ocular clinical relapses) and MRI disease activity during the follow-up period. RESULTS: The study included 102 MS patients with a mean follow-up duration of 3.9 ± SD years. At the last follow-up assessments, there were significant thinning of the average macular thickness (AMT) (p < .001), macular nerve fiber layer (MRNFL) (p < .001), ganglion cell-inner plexiform layer (GCIPL) (p < .001), and the peripapillary nerve fiber layer (PRNFL) (p < .001), compared to baseline. Early disease duration up to 10 years was associated with thinning of AMT, PRNFL, and GCIPL, while longer disease duration (> 15 years) was associated with only GCIPL thinning. Prior optic neuritis was predictive of more thinning of PRNFL (p = < .01), while MRI activity and female gender were significantly associated with more MRNFL thinning (p = < .01). CONCLUSION: MS is associated with longitudinal thinning affecting AMT inner retinal layers (MRNFL, GCIPL, PRNFL). Early disease duration, female gender, MRI activity, and prior optic neuritis were predictive of faster rate of neuro-axonal loss. This may have implications in the design of future therapeutic trials.

Retinal nerve fiber layer thickness and neurologic disability in relapsing-remitting multiple sclerosis.

OBJECTIVE: To assess the correlation between disability progression assessed by expanded disability status scale (EDSS) and peripapillary retinal nerve fiber layer thickness (RNFLT), macular thickness and macular volume obtained by spectral domain OCT (SDOCT) in patient with relapsing-remitting multiple sclerosis. METHODS: We conducted a cross sectional study by recruiting 104 with relapsing-remitting MS patients and 51 healthy controls. Patients' clinical characteristics and neurologic disability was recorded from the subject clinical records. All patients had complete neuro-ophthalmic and neurological assessments. SDOCT performed to obtain peripapillary RNFLT, macular thickness and volume. RESULTS: There was a statistically significant correlation between the mean EDSS scores and the average RNFLT (p = 0 .006; r = − 0.268) along with superior (p = 0.020; r = − 0.228), inferior (p = 0.007; r = − 0.262) and temporal (p = 0.031; r = − 0.212) quadrants. However, macular thickness (p = 0.205; r = − 0.125) and volume (p = 0.178; r = − 0.133) were not significantly correlated with EDSS scores. CONCLUSION: Our study showed a significant correlation between RNFLT and disability progression assessed by mean of EDSS in patients with relapsing-remitting MS. RNFLT can be a useful tool to estimate neurological disability in newly diagnosed patients or patients with early RRMS.