Inhibitory control and working memory using saccadic eye movements in primary glaucoma

Glaucoma is a progressive optic neuropathic disorder that significantly impacts the activities of daily life (ADLs) of individuals. Emerging studies indicate degenerative changes in cortical and subcortical regions in individuals with glaucoma, which are associated with cognitive processes and oculomotor control. Cognitive processes involving top-down processes such as attention, planning, task management and execution, are crucial for meeting the demands of everyday tasks, and are affected in glaucoma. This study investigated the executive functions, specifically inhibitory control (IC) and working memory (WM), in individuals with glaucoma compared to age-matched controls, using eye movements. This was achieved through four tasks sensitive to executive functions, including antisaccade, memory-guided prosaccade and antisaccade, and the Go-NoGo tasks. Saccadic eye-movement parameters were also assessed in a prosaccade task, considered as a control condition with minimal IC and WM load. The results indicated that glaucoma is associated with changes in both IC and WM. Increased anticipatory saccadic errors might be linked to inhibitory deficiencies during the preparatory stage of the saccadic suppression mechanism. The increased omission errors in the antisaccade task might be due to the lack of regulation of the WM component. Taken together, these findings provide evidence for the involvement of cognitive deficits in individuals with glaucoma.