Slower retinal thinning over a year predicts continuous NEDA status at follow-up in multiple sclerosis: A longitudinal OCT study.

Abstract

Introduction: Retinal layer thickness measured by optical coherence tomography (OCT) correlates with disability and disease activity in multiple sclerosis (MS), yet there is scarce data on the ability of retinal OCT rates of change to predict subsequent continuous disease stability.

Aims: To investigate whether the rate of change in retinal OCT measures during the first year of monitoring can predict maintenance of continuous "No evidence of disease activity" (c-NEDA) status in MS.

Methods: We conducted a longitudinal study of people with MS (PwMS) from our observational cohort (AMIR) at the American University of Beirut. Cases included had at least three spectral-domain OCT scans at baseline, 12 months, and at the last visit. Mixed effects regression (controlling for age, sex, disease duration, EDSS, gap time from initiation of current DMT to first OCT scan, type of DMT, and history of optic neuritis per eye) was performed to explore the differences between the annualized changes in retinal layer thicknesses (microns/year) during the first year in the c-NEDA group compared to those with evidence of disease activity (EDA) at any point during follow-up.

Results: In total, 222 eyes of 111 RRMS cases (67 females, 60.4%) were included and followed up clinically for a median (min-max) of 5.24 (3-8.64) years. During the study period, 51 (45.9%) cases maintained c-NEDA, and 60 (54.1%) had EDA. In regression models, EDA cases had greater mean retinal thinning rates during the first year of observation compared to c-NEDA cases with an annualized loss (microns/year) in pRNFL of -1.84 versus 0.03 (p < 0.0001); in macular RNFL -1.86 versus -0.76 (p < 0.0001); in GCIPL -0.13 versus 0.53 (p = 0.008); and in retinal thickness -3.81 versus -1.06 (p < 0.0001).

Conclusion: Our data support the potential value of retinal OCT in prospectively identifying PwMS likely to maintain c-NEDA status versus EDA during follow-up, guiding proactive treatment strategies.