Visual problems are frequently reported by patients post-concussion, but to date there have been few prospective studies investigating the frequency of such vision disorders. Multiple studies suggest that vision problems may influence concussion recovery; in fact, vision problems were identified as the primary cause of persistent symptoms in an oculomotor subtype of concussion. Now, research supports incorporating oculomotor testing into medical assessments of concussive brain injury.

Researchers in Philadelphia and Aurora, CO, examined post-concussion vision diagnoses in adolescents and the ability of a screening to detect convergence and accommodative disorders post-concussion. The study included 113 subjects aged 11 to 17, followed for four to 12 weeks after a diagnosed concussion. The children were evaluated by a sports medicine physician at their first concussion exam who measured near point of convergence (NPC), monocular accommodative amplitude (AA) and symptoms based on the Convergence Insufficiency Symptom Survey (CISS). An optometrist performed a comprehensive oculomotor evaluation.

Post-concussion, 79 of 113 (70%) children had at least one oculomotor diagnosis and 47% had more than one diagnosis. The most common problems were vergence disorder, found in 60% of patients, and accommodative disorders, present in 57%. Among those with vergence disorders, 35% had convergence insufficiency; among those with accommodative disorders, accommodative insufficiency was the most common (35%). Physician screening sensitivity for NPC, AA and CISS was 63%, 43% and 48%, respectively.

The study didn’t include an age-matched control group of neurologically normal, non-concussed adolescents, but the researchers noted a study assessing NPC in 295 non-concussed adolescents, aged six to 18, that found only 2.4% of subjects failed NPC with a ≥6cm criterion.

The researchers concluded that vision problems are common in adolescents in the sub-acute phase four to 12 weeks post-concussion. Based on the physician screening sensitivity in this study, the researchers believe that current methods using NPC, AA and CISS are underperforming. “As standalone tests, the NPC and AA tests are somewhat useful but could result in an unacceptable false negative rate,” they wrote in their paper. “Other combinations of screening tests were also evaluated (NPC + CISS and AA + CISS), but none yielded a satisfactory combination of sensitivity and specificity.”