Prevalence of esophoria in concussed patients.

PURPOSE To assess the prevalence of esophoria at near in concussed patients in a neuro-optometric private practice setting. METHODS A retrospective analysis was performed involving a chart review in a neuro-optometric, private practice setting of consecutive patients with a medical diagnosis of concussion from January 1st 2016 to December 31st 2016. A total of 71 patients were included in the analysis. All received a comprehensive vision examination, with a near vision emphasis. The near horizontal phoria was assessed with the cover test and the von Graefe test. RESULTS Approximately 30% of the patients with a medically based diagnosis of concussion exhibited esophoria at near, with good agreement (95%) between the two tests. Mean esophoria was 5.2 (SD=2.8) prism diopters (pd), with a range from 2pd to 14pd of esophoria. Convergence excess was diagnosed in 23%. DISCUSSION Near esophoria was found in nearly one-third of this practice-based sample of concussed patients. Thus, it was more common than typically believed to be the case. Two proposed oculomotor-based mechanisms related to these symptomatic esophoric patients included phoria decompensation and excessive accommodative vergence.