Prevalence of Oculomotor Dysfunction in Healthy Athletes Preseason: Implications for Concussion in Sport

Abstract

Background: Measures of oculomotor function are becoming more frequently employed as part of comprehensive concussion assessments. However, performances on many of these oculomotor measures have not been examined in a healthy athletic cohort. The purpose of this study was to characterize performance of university level athletes on a battery of oculomotor tests and identify any potential influence of gender and history of concussion. Methods: 259 healthy university level athletes (males, n = 150; females, n = 109) completed an oculomotor screening battery prior to the start of their competitive season. The battery assessed stereopsis, visual acuity, monocular amplitude of accommodation, near point of convergence, monocular and binocular accommodative facility, vergence facility, positive and negative fusional vergence, and saccades. Athletes also completed the Convergence Insufficiency Symptom Survey (CISS). Results: Three oculomotor tests (stereopsis, convergence, saccades) showed significant differences between male and female athletes at P<0.05, uncorrected. A high percentage of athletes were identified as having oculomotor deficiencies including abnormal acuity (34.2%), vergence infacility (28.6%), abnormal horizontal saccades (21.7%) and accommodative infacility (18.7%). Convergence insufficiency differed by method of assessment, ranging from 11.0-15.7%. Conclusion: A significant proportion of healthy athletes displayed abnormal performance across a variety of oculomotor indices. A history of lifetime concussion (i.e., greater than 12 months prior to study) did not significantly influence oculomotor test performance. Clinicians should be aware of such differences and potential implications associated with postconcussion evaluations.