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

## TL;DR

This study explores how blink rates during eye movements relate to pain perception in chronic pain patients, finding no direct link to pain or anxiety.

## Contribution

The novel contribution is investigating blink rate during saccadic eye movements as a potential biomarker in chronic pain patients.

## Key findings

- Blink rates during horizontal and vertical saccadic tasks were significantly correlated.
- No correlation was found between blink rate and pain perception or anxiety scores.
- Pain perception measures were positively correlated with each other and with anxiety scores.

## Abstract

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.