Chronic Neck Pain Influence on Oculomotor Performance During Near Point Convergence and Fitts's Tasks: a cross-sectional study.

Objective: The purpose of this study was to quantify the influence of musculoskeletal dysfunction on oculomotor performance by evaluating oculomotor convergence and volitional gaze performance in participants with chronic neck pain compared with controls.

Methods: Twelve participants with chronic neck pain were age/sex matched to 12 asymptomatic participants. All participants completed a series of tests in neutral, trunk rotated right, and trunk rotated left positions. A Royal Air Force ruler was used to measure near point convergence (NPC), a convergence insufficiency (CI) measurement. Oculomotor performance was assessed using an oculomotor Fitts's Law task. Questionnaire data included the neck disability index (NDI) and CI symptom survey (CISS).

Results: A significant reduction in NPC was found in participants with neck pain for the neutral and rotated left positions. Movement time increased for targets at farther amplitudes for both groups. Reaction time increased for targets at shorter amplitudes for the symptomatic group, indicating motor planning challenges. Significant correlations were found between CISS and NPC scores, as well as between CISS and NDI scores, indicating CISS scores are associated with convergence performance deficits. Greater NDI scores related to larger CISS scores, correlating to increased CI symptoms.

Conclusion: Significant differences between groups were found for NPC suggesting that symptomatic participants have difficulties controlling convergent eye movements compared with asymptomatic participants. Reaction time was found to be longer for index of difficulty at a shorter amplitude for the symptomatic group. Correlations between CISS scores with NPC and NDI scores respectively were found, providing evidence of a relationship between CI and neck disability.