Identifying and Managing Patients With Concussion

Imagine that a middle-aged patient has just walked into your office for an eye examination after experiencing a concussion from a car accident the week before. The patient reports that ever since the accident, their vision feels “off,” and they can’t tolerate their new progressive lenses. The patient is also experiencing right eye pain, nausea, and headaches after only 5 minutes of computer use, and is photophobic. Their VA is 20/20 OU at distance and near; their progressive lenses previously worked fine 3 weeks ago and still fit appropriately; cover test results are orthophoric at distance and near; and eye health, visual fields, and OCT results appear normal. So, what could be causing this patient’s visual symptoms, and what should you do?

VISUAL EFFECTS OF TRAUMATIC BRAIN INJURY

Traumatic brain injuries (TBIs) occur in 64 to 74 million people globally each year, and 70% to 90% are considered to be of mild severity (mTBI) using the Glasgow Coma Scale.¹ Although 54% to 80% of patients with a TBI will have visual complaints,^2,3 it is rare to have permanent visual field and visual acuity loss with an mTBI, such as a concussion.² Thus, it is important to reassure the patient that the comprehensive eye health and refractive examination results are (and should be) normal before probing further into their subjective visual complaints: Do they have double or overlapping vision? Is there blur around the edges? Are the images clear, but moving so quickly they appear to shimmer or smear? Sometimes patients have trouble verbalizing their symptoms, and it can be helpful to use pictures to help them describe what they see (Figure).

The most common cause of visual complaints post-concussion is vestibular-oculomotor dysfunction (VOD). VOD occurs in up to 50% to 90% of adults,^4-8 and 76% of pediatric patients acutely and 24% chronically > 4 weeks after concussion.⁹ Eye pain, headache, nausea with computer use, and progressive lens intolerance can all be symptoms of VOD.

DIAGNOSING VOD

For primary eye care clinicians not routinely employing a comprehensive battery of binocular vision tests, a screening tool such as the Vestibular Oculomotor Screening Assessment (VOMS) can be an excellent ancillary test to employ.¹⁰ VOMS is a quick, simple validated screening assessment of symptom provocation with oculomotor testing that can be employed in the examination room without the need for additional equipment to confirm the suspicion of a diagnosis of VOD (see details in Modalities Screened in VOMS).^11,12 Patients with VOD often become intolerant to the peripheral aberration of progressive lenses, which is why the lenses may suddenly provoke nausea and discomfort after a TBI.

In some cases, the refraction remains stable, and you will need to change the lens modality and temporarily switch into single vision distance and near glasses or contact lenses until VOD resolves. For other patients, the uncorrected refractive error that they were previously able to compensate for now needs to be corrected, as the patient is more dependent on their visual system for balance with their vestibular system damaged by concussion. Be careful, though, because a little bit of correction goes a long way. Many patients have accommodative and convergence spasms, and sometimes over-correcting a patient to achieve the best visual acuity can exacerbate their headache and/or oculomotor dysfunction.

ADDITIONAL TESTING TO CONSIDER

One of the subtests of VOMS is near point of convergence (NPC). Up to 89% of visually symptomatic post-concussion patients will have grossly abnormal NPC, generally higher than that found in the general population, which is about 10% to 17%.^13,14 Interestingly, of patients with reduced NPC post-concussion, only 8% actually have true convergence insufficiency (CI), as defined by the Convergence Insufficiency Treatment Trial,^14,15 while the majority of patients are actually experiencing an accommodative disorder and/or other oculomotor dysfunction.¹⁶ It is posited that post-traumatic CI may be a separate entity from developmental CI and may rehabilitate differently.¹⁷ It is not uncommon for post-traumatic CI to present with a normal orthophoric or even an esophoric ocular posture on cover test, and yet have a drastically reduced NPC breakpoint of 20 cm or further away, with an even further reduced recovery point. Post-TBI, CI may present with fatigue on NPC, where the NPC gets worse with repetition, provoking severe symptoms of headache, dizziness, brain fog, and/or nausea. Additionally, post-TBI patients with CI may have drastically reduced fusional convergence and divergence ranges, so they are less likely to tolerate compensatory BI prism prescriptions that are routinely prescribed for developmental CI.

Although VOMS is a wonderful VOD screener, it lacks accommodative testing. Accommodative dysfunctions such as insufficiency, infacility, ill-sustained, and spasms are the most common post-concussive oculomotor dysfunction (about 43.2%),² so it is imperative to add this to the testing battery, even for patients with presbyopia.

For example, if a 45-year-old patient requires a +2.50 add after a TBI, that should be a red flag that their accommodative system is not functioning at age-expected norms. Post-concussive accommodative dysfunction in a presbyope can be tricky to treat because an increase in add needed to alleviate the near blur will reduce the working distance, thereby exacerbating any diplopia caused by post-concussion convergence dysfunction. In these cases, active orthoptic vision therapy is needed to restore the patient to their presbyopic accommodative and convergence norms.

TREATMENT PLAN

If you work in a primary care setting and see a patient 1 week post injury, document the VOMS score and counsel the patient that, in the majority of cases (about 80%), symptoms will self-resolve within 3 to 4 weeks.^9,18 If they absolutely cannot tolerate their progressives, switch the modality and have them come back in 3 weeks. If the VOD is not resolved at the follow-up (ie, they still have an abnormal VOMS), refer the patient to a neuro-optometrist for active rehabilitation. Active vision therapy and vestibular physical therapy have been shown to expedite post-concussion recovery faster than rest alone.¹⁹ When the VOD goes away, the progressive lens intolerance usually diminishes as well, such that their progressive lenses from before the TBI magically work again, saving your office the redo.

Managing Photophobia

What about light sensitivity? First, rule out an ocular etiology. If the photophobia fluctuates with time of day independent of the patient’s headaches and is non-wavelength specific, look to the ocular surface. Dry eye is more common in patients with a history of TBI,²⁰ as well as those with post-TBI comorbidities such as migraines, sleep deprivation, and sleep apnea. However, if the photophobia is constant, wavelength-dependent (ie, associated with fluorescent lights, electronic devices, or UV light), and beginning within 24 hours of injury, it is more likely post-traumatic photophobia, which has a vast differential diagnosis and complicated treatment pattern.²¹ Tinted lenses may inhibit the natural neural adaptation to light and, thus, exacerbate photophobia and prolong recovery.²² I would recommend that the patient only wear sunglasses indoors if absolutely needed for the first 72 hours or up to 1-week post concussion, and then gradually wean themselves off the sunglasses indoors. They can of course wear sunglasses outdoors. If the photophobia persists, the patient should be referred to a specialist to differentiate the etiology and weigh the risk-benefit ratio of tinted lens use and the type of tint (ie, blue vs. FL41) required for relief.

DON’T DELAY

Persistent concussion symptoms that continue longer than 4 weeks are a multidisciplinary problem and require a multidisciplinary assessment and management plan. Unilateral eye pain with computer use could be oculomotor in origin or the result of dry eye, but it could also be referred cervicogenic pain from a corresponding whiplash injury or part of your patient’s post-traumatic headache pattern. If your patient is not self-recovered 3 to 4 weeks after the initial injury, refer them to an appropriate specialist.¹⁹ Delayed referral means delayed recovery. The most common thing we hear in our office from patients still experiencing symptoms for months or even years after a concussion is, “I wish someone would have referred me to you sooner.”