Binocular Vision Dysfunction After Mild Traumatic Brain Injury
A 28-year-old woman presents with headaches, blurred vision, and difficulty reading 3 months after a mild traumatic brain injury (concussion). She reports symptoms worsen with prolonged near work and she has to close one eye to read. She has no prior history of strabismus or amblyopia. Examination: visual acuity 20/20 OU, pupils normal, extraocular movements full but she reports diplopia at near. Cover test: 6 prism diopters esophoria at distance, 12 prism diopters esophoria at near. Near point of convergence (NPC) is 18 cm (break), 25 cm (recovery). Accommodative amplitude is 4 D (expected 10 D). She has a history of migraine.
1. What is the most likely diagnosis and what additional tests would you perform?
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The diagnosis is convergence insufficiency (CI) and accommodative insufficiency, likely post-concussion. Additional tests include: fusional vergence amplitudes (positive and negative), accommodative facility, and perhaps a neurological evaluation if symptoms are progressive. Also, assess for oculomotor dysfunction (saccades, pursuits) and vestibular-ocular reflex. Consider a screen for post-trauma syndrome. The history of migraine may exacerbate symptoms.
2. What treatment plan would you recommend, and how would you monitor progress?
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Treatment: office-based vision therapy (vergence and accommodative therapy) is first-line. Home therapy with pencil push-ups or computer-based vergence exercises can be adjunctive. Consider prism reading glasses for immediate relief, but not as a substitute for therapy. Address environmental factors (lighting, breaks). Monitor with repeat NPC, fusional vergence ranges, and symptom questionnaires (e.g., CISS). If no improvement in 8-12 weeks, consider referral to neuro-optometry or occupational therapy. Also, manage migraine with neurology.