Eye Recovery Automation for Post Injury Dysfunction (iRAPID)

Mild Traumatic Brain Injury (mTBI) Cohort Inclusion Criteria:

• are aged 18 - 40;
• have suffered a mTBI according to VA/Department of Defense (DoD) criteria with documented evidence of alteration of consciousness (AOC) \< 24 hours or loss of consciousness (LOC) less than 30 minutes;
• were injured between 1 month and 15 years ago;
• received a Glasgow coma scale (GCS) score of between 13 and 15 upon emergency department (ED) admission, if available;
• experienced less than 24 hours of post-traumatic amnesia (PTA), if any;
• have ongoing post-concussive symptoms as evidenced by a score of 18 or greater or a score of 2 or greater on question 6 (vision problems, blurring, trouble seeing) on the Neurobehavioral Symptom Inventory (NSI);
• have ongoing vision-related symptoms as evidenced by a score of 31 or higher on the Brain Injury Vision Symptom Survey (BIVSS);
• have PTCI as evidenced by obtaining a score of 21 or higher on the convergence insufficiency symptom survey (CISS), a specific measure of convergence insufficiency;
• are fluent in English; and
• have been on stable doses of any vision-altering medications for the past 2 months.
• Stereopsis of 500 sec arc using Randot Stereo Test.
• Exophoria at near 4 prism-diopter (PD) or greater than magnitude at distance
• Near point of convergence (NPC) > 5 cm
• Convergence amplitude at near \< 15PD break or the Sheard criterion not met

Control Inclusion Criteria

• are aged 18 - 40;
• CISS score of 20 or lower;
• near point of convergence (NPC) \< 6cm; and
• positive fusional range >15 prism diopters.
• Stereopsis of 500 sec arc using Randot Stereo Test.

Exclusion Criteria

• prior history of other neurological diseases, so as to reduce the risk of confounding effects on vision;
• history of psychosis, as there are known visual performance findings associated with psychosis;
• history of current or recent (within two years) substance/alcohol dependence, to reduce confounding effects on visual function
• recent medical hospitalization (within three weeks), to reduce risk of rehospitalization during the study;
• any condition that would prevent the participant from completing the protocol;
• appointment of a legal representative, to avoid coercion of a vulnerable population;
• any ongoing litigation related to TBI, to prevent interference with legal proceedings;
• membership in an identified vulnerable population, including minors and prisoners, so as to prevent coercion.
• Previous vergence therapy, orthoptics, home-based therapy, etc.
• Amblyopia or constant strabismus or strabismus surgery.
• High refractive error: Myopia ≥ 6.0PD sphere; Hyperopia ≥ 5.0PD sphere; Astigmatism ≥ 4.0PD; Anisometropia >1.5PD difference between eyes; Prior refractive surgery.
• Manifest or latent nystagmus evident clinically.
• Systemic diseases that affect accommodation, vergence, or ocular motility (i.e. multiple sclerosis, Graves' thyroid disease, myasthenia gravis, diabetes, chemotherapy or Parkinson disease).