Identification of Binocular Vision Dysfunction (Vertical Heterophoria) in Traumatic Brain Injury Patients and Effects of Individualized Prismatic Spectacle Lenses in the Treatment of Postconcussive Symptoms: A Retrospective Analysis

Abstract

OBJECTIVE: To identify a form of binocular vision dysfunction (vertical heterophoria) in a traumatic brain injury (TBI) population and to assess the effect of individualized prismatic spectacle lenses on postconcussive symptoms. DESIGN: Retrospective study. SETTING: Private physical medicine and rehabilitation practice and private optometric practice. PATIENTS: A subset of TBI patients who were initially evaluated by a single physiatrist and who received standard treatments and medications yet had persistent postconcussive symptoms. These patients were then assessed by a single optometrist, and those found to have vertical heterophoria were treated with individualized prismatic spectacle lenses. A total of 83 patients were referred for testing; 77 were positive for vertical heterophoria on screening, of which 43 had complete data sets and were included for analysis. INTERVENTIONS: All patients were treated with individualized prismatic spectacle lenses to correct for vertical heterophoria. MAIN OUTCOME MEASURES: Outcomes were measured by the difference in score before and after intervention of an objective, self-administered vertical heterophoria symptom burden instrument (Vertical Heterophoria Symptom Questionnaire [VHS-Q], presently undergoing validation) and by subjective improvement in symptoms as expressed by the patient at the end of intervention. RESULTS: There was a 71.8% decrease in subjective symptom burden when compared with preintervention baseline. There was a mean 16.7 point absolute reduction in the VHS-Q score on a 75-point scale, which represents a relative reduction in VHS-Q score of 48.1%. CONCLUSION: Vertical heterophoria was identified in a group of TBI patients with postconcussive symptoms and treatment of the vertical heterophoria with individualized prismatic spectacle lenses resulted in a 71.8% decrease in subjective symptom burden and a relative reduction in VHS-Q score of 48.1%. It appears that vertical heterophoria can be acquired from TBI.