Eye-tracking as a Digital Biomarker of Processing Speed and Mobility in Multiple Sclerosis
Diogo Santos1, Dagoberto Callegaro2, Carolina Moura4, Maria Tereza Martinez3, Rafael Carneiro1, Amanda Rodrigues5, Caio Goes5, Alex Kinderman6, Renato Anghinah3
1Neurology, Irmandade da Santa Casa de Misericórdia de São Paulo, 2Neurology, Universidade de São Paulo, 3Universidade de São Paulo, 4Hospital Universitário Antonio Pedro, 5Faculdade de Ciências Médicas da Santa Casa de São Paulo, 6Spryson America INC
Objective:
To investigate the associations between eye-tracking metrics and walking performance in patients with Multiple Sclerosis (MS), exploring oculomotor behavior as a potential digital biomarker of processing speed and mobility.
Background:
The Timed 25-Foot Walk (T25FW) is a quantitative test of mobility and leg function widely used in MS. Efficient walking requires rapid visuomotor integration, attentional shifting, and cerebellar timing, which are functions reflected in eye-movement control. Eye-tracking may reveal subtle neurophysiologic correlates of gait and processing speed. We aim to examine associations between eye-tracking metrics and walking performance in patients with MS, exploring oculomotor parameters as potential digital biomarkers of processing speed and mobility.
Design/Methods:
We evaluated 104 MS patients (mean age 37.3 ± 10.4 years; 74% female) using the Neurolign Dx100 eye-tracking system, assessing fixation, saccadic, pursuit, and vergence tasks. Spearman correlations were calculated between 65 eye-tracking variables and T25FW times (forward, backward, and mean). Lower T25FW times indicate faster walking.
Results:
Fixation Light parameters (on PSPV and ASPV, across horizontal and vertical gaze) correlated positively with slower T25FW performance (ρ = 0.26–0.30, p < 0.01), suggesting that impaired fixation stability and longer visual latency accompany reduced gait speed. Vergence Pursuit metrics, including Saccadic Component and Far Lag Asymmetry showed negative correlations with T25FW mean (ρ ≈ –0.21 to –0.24, p = 0.02–0.04), indicating that better binocular coordination are related to faster ambulation. These associations were consistent across walking directions.
Conclusions:
In MS, poorer fixation and vergence control were linked to slower T25FW performance, underscoring shared frontocerebellar mechanisms underlying ocular and motor coordination. Eye-tracking may serve as an objective, scalable digital biomarker of processing speed and functional mobility in MS.
Disclaimer: Abstracts were not reviewed by Neurology® and do not reflect the views of Neurology® editors or staff.