Blink rate during saccadic eye movements: insights from patients with chronic pain

Chronic pain (CP) significantly impacts quality of life and poses an increasing economic burden on healthcare systems worldwide. This study investigates the relationship between blink rate during saccadic eye movements and pain perception in patients with CP. Ninety-two patients with CP (24 men, 68 women) were assessed using eye-tracking technology during horizontal and vertical saccadic tasks. Pain perception was evaluated using the Central Sensitization Inventory - Part A and the McGill Pain Questionnaire, and anxiety levels were measured using the State-Trait Anxiety Inventory. The results revealed a significant correlation between blink rates in horizontal and vertical tasks (ρ = 0.668, P < 0.001). However, there was no correlation between blink rate and age, pain perception, or anxiety scores. Conversely, measures of pain perception were positively correlated with each other and with anxiety scores. These findings suggest that while blink rate may reflect oculomotor function, it is not directly influenced by pain perception or anxiety in patients with CP. The present study highlights the potential of eye tracking for the comprehensive assessment and management of patients with CP.