The Discrepancy between Subjective and Objective Measures of Convergence Insufficiency in Whiplash-Associated Disorder versus Control Participants

Abstract

Motor vehicle accidents (MVAs) are a pandemic associated with human suffering and a burden to national economies. Whiplash-associated disorders (WADs) after MVAs are associated commonly with disability claims, many of which are related to vision. Convergence insufficiency (CI) leads to visual disability associated with symptoms of ocular discomfort. We examined the incidence of symptoms and findings consistent with CI in a cohort of patients after MVA-related WAD compared with age-matched control participants. Prospective cohort study. Patients with WAD after MVA were recruited from the Orthopedic Emergency Department between July 2014 and March 2017. Control participants were recruited among hospital personnel and relatives of WAD patients. The Convergence Insufficiency Symptom Survey (CISS) questionnaire was completed by each participant, followed by a detailed visual examination including measurements of distance and near best-corrected Snellen visual acuity, distance and near cover test, Randot stereopsis, Maddox distance and Maddox-Thorington near heterophoria, near point of convergence, base-out step fusional reserves, and amplitude of accommodation using the push-away method. The CISS score and binocular measure findings of CI were recorded and analyzed using Student's t test, the chi-square test, and multiple logistic regression adjusted for age and gender. A pathologic CISS score of 16 or more occurred in 26 of 57 WAD patients (45.6%) compared with 6 of 39 control participants (15.4%; P= 0.002). Absolute CISS score was higher in the WAD group compared with the control group (15.3±10.0 vs. 7.7±7.7; P < 0.001). Findings consistent with CI occurred in 7.0% of WAD patients and 7.7% of control participants (P= 0.90). Visual symptoms suggestive of CI were reported more frequently among WAD patients compared with control participants, yet the incidence of examination findings indicating weakness of convergence was not increased. The discrepancy between subjective and objective measures of CI in WAD patients versus control participants stresses the importance of training healthcare personnel to assess disability using objective, validated standards of examination.