Evaluation of Visual Disturbances After Mild Traumatic Brain Injury-A One-Year Follow-up Study.

Abstract

To examine the persistence of visual symptoms in mild traumatic brain injury (MTBI) during the first months after injury. It is important to recognize visual disturbances because they can delay return to normal activities, while they might be simultaneously treated by visual therapy. Here we describe the results from a 1-year follow-up study of visual disturbances after MTBI. The study group comprised 26 patients from the Brain Injury Clinic of the Helsinki University Hospital. Inclusion criterion was a high score (≥21p) on the Convergence Insufficiency Symptom Survey (CISS) at an appointment with a neurologist within 6months after injury. The patients underwent baseline vision evaluation at 4months on average and follow-up at 14months after injury. The evaluation included tests for visual acuity, near point of convergence, convergence facility, near point of accommodation, accommodative facility, motility, heterophoria, binocular vision, dynamic visual acuity, and fusional vergence width at near and far distances. Further assessments included the Rivermead Post Concussion Questionnaire for posttraumatic symptoms, a visual analog scale for visual fatigue, and the Developmental Eye Movement Test for saccadic eye movements. Both CISS and Rivermead Post Concussion Questionnaire scores improved significantly from baseline to follow-up. The overall level of visual fatigue according to visual analog scale score was lower at follow-up, but the increase in visual fatigue (comparing fatigue before and after assessment session) was significant both at baseline and follow-up. In visual function assessments, spontaneous recovery from baseline to follow-up could be seen in vergence facility and pursuit eye movement but not in near point of convergence, near fusion, distance fusion, heterophoria, and dynamic visual acuity. The results point out the importance of evaluation of visual disturbances after MTBI. Early detection of these disturbances may provide an opportunity to provide visual therapy.