Multifractal characterization of nystagmus eye movements.

This article investigates the multifractal properties of eye movement velocity dynamics in children with infantile nystagmus (IN), a condition causing involuntary eye movements, compared to children without ocular pathologies. Using Multifractal Detrended Fluctuation Analysis (MF-DFA), four indices—the classical Hurst exponent, singularity strength (α₀), asymmetry (A) of the singularity spectrum, and multifractal strength (W)—were extracted from eye-tracking velocity data during a visual task. Results show that children with IN exhibit significantly lower values in most indices, indicating less persistent and less variable eye movement dynamics, with a more symmetric multifractal spectrum compared to controls. Both unsupervised and supervised machine learning techniques applied to these indices effectively distinguished IN patients from controls, suggesting that multifractal features of eye movement velocity can serve as objective biomarkers for IN without requiring classification of eye movements into saccades or fixations. The study highlights the potential of multifractal analysis in characterizing IN and calls for further research with larger, diverse cohorts to validate these findings.