Saccadic eye movements in neurological disease: cognitive mechanisms and clinical applications

Abstract

Saccadic eye movements are rapid, precisely coordinated shifts that centre the fovea on a visual target. Their control relies on the integration of cognitive processes spanning multiple brain regions. High-resolution video-oculography enables precise measurement of saccadic dynamics, offering a window into disruptions affecting these networks. This review examines the neuroanatomy and physiology of saccadic eye movements, emphasising the cognitive mechanisms underlying their control and the methodologies used for their assessment. We synthesise evidence from saccadic eye movement testing across a spectrum of neurological diseases, highlighting its potential as an early and sensitive biomarker for detecting subclinical disease impact. While current findings underscore its promise as a non-invasive, objective tool for tracking neuropsychological dysfunction in these various diseases, we also address existing limitations and critical directions for future research towards improving clinical utility.

Keywords: Cognitive science; Neurological disease; Neuroophthalmology; Neuropsychology; Saccadic eye movements.

Fig. 1

Schematic of the neural circuitry underlying saccade generation, highlighting pathways for volitional and reflexive eye movements. Volitional saccades are initiated in the frontal cortex (yellow connections) and include the frontal eye fields (FEF), dorsolateral prefrontal cortex (DLPFC), anterior cingulate cortex (ACC) and supplementary eye fields (SEF), which exert top-down control over subcortical structures. Reflexive saccades (purple connections) are driven by bottom-up visual input from the visual cortex (VC) projecting to both the parietal eye fields (PEF) and FEF, thalamus (THAL) and basal ganglia. Both cortical streams influence the basal ganglia network (blue connections) at the caudate nucleus (Cd), which modulates output via the direct and indirect pathways through the globus pallidus (GP) and substantia nigra pars reticulata (SNr). The cerebellum (CB) and thalamus provide additional modulator input. Both volitional and reflexive pathways converge on the superior colliculus (SC) and downstream brainstem premotor circuits (pons) to execute saccades. Created in BioRender. Wang, YL. (2025)

Fig. 2

Temporal and spatial schematics of A, the prosaccade task and B, the antisaccade task. In the prosaccade task, the participant is instructed to saccade to a visual target that appears randomly either to the left or the right quickly and accurately. In the antisaccade task, the participant is asked to saccade to an imaginary, mirrored location of the appearing target. Created in BioRender. Wang, YL. (2025)