Case Challenge 07 – January 2019

Case Challenge 07

A 25 year old woman was involved in a minor automobile accident where she was hit by another driver. The accident was reportedly minor, with no initial injury to either driver, and both cars were able to be driven away. She felt that she experienced only a mild-to-moderate bump during the accident with no head trauma or loss of consciousness. However, immediately upon waking the next morning, though she had no physical pain, she experienced profound double vision.

She described the diplopia as vertical and worse at near. She had a distinct right hyper deviation which, on alternate cover test, worsened in left gaze and right head tilt. This was a signature motility of a cranial IV (trochlear) palsy.

A large percentage of CN IV palsies are congenital. With acute onset in older adults, there is frequently concurrent hypertension and/or diabetes. In isolated acquired cases often there will be a history of (head) trauma immediately preceding development of the CN IV palsy. The trauma need not be major as relatively minor injuries can precipitate CN IV palsy. In cases of longstanding decompensated CN IV palsy, the inciting trauma may have been many years antecedent. The fourth nerve is especially prone to trauma as it exits the brain stem and courses through the subarachnoid space. The most common causes of damage to the fourth nerve in this region are trauma and ischemic vasculopathy.

During the post-traumatic diplopic phase, temporary prisms or occlusion may resolve symptoms. A single injection of botulinum toxin A into the ipsilateral inferior oblique muscle can rapidly and safely resolve symptomatic diplopia while waiting for spontaneous recovery.

Despite the auto accident being apparently minor, the fact that she manifested a cranial neuropathy the next day was too coincidental to ignore. CT imaging ruled out a cerebral hemorrhage. The patient was temporarily patched to deal with the diplopia and eventually received a prismatic correction for the residual imbalance.

It is important to remember that trauma causing a CN IV palsy need not be directly to the head or even severe.


Click on the toggles below to read previous case challenges.

Case Challenge 06 – November 2018

Optometric Education Consultants Clinical Case Challenge A 21 year old male plumber called in requesting an urgent appointment. He was working on a job and trying to dislodge a drain coupling by hammering it with the blunt end of a screw driver. He missed,...

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Case Challenge 05, Explained – October 2018

  A 47-year-old man presented complaining of gradually decreasing vision and monocular diplopia in his right eye for approximately the past 18 months. He had undergone LASIK vision correction over 13 years earlier with an excellent emmetropic...

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Case Challenge 05 – September 2018

A 65 year old woman previously diagnosed with primary open angle glaucoma presented for ongoing care. She was using latanoprost in each eye and had bilateral selective laser trabeculoplasty performed two years earlier. Her medical history was significant for hypertension, elevated cholesterol, and arthritis.  Her vision was 20/20 OD and 20/25 OS. She had an inferior retinal nerve fiber layer defect in the right eye and significant superior rim damage in the left eye. Threshold perimetry showed the above corresponding visual field defects.

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Case Challenge 04 – August 2018

The first patient is a 16 year old male whose vision has been fluctuating for 6 weeks. He also complains about headaches. His primary care physician feels it’s a normal growth spurt and Mom feels it’s migraines as there is a strong family history, but she still wants eyes checked. His vision is 20/20 OD/OS uncorrected and he has bilateral optic disc edema.

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Case Challenge 03 – July 2018

A 35 year old man presents wanting another opinion due to “blood on my right eye”. He says that everything happened 3 days ago after violently vomiting, reportedly due to food poisoning from chicken Caesar salad. He still feels a little nauseated and somewhat “not himself”. He saw another practitioner 3 days ago, was told he had a ‘bruise’ on his eye and it should go away in 1-2 weeks. From the outward appearance, he seems to simply have just a subconjunctival hemorrhage…or does he?

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Case Challenge 02 – June 2018

A 13 year old female was referred for painless reduced vision (20/40) in her left eye with a concurrent abnormal screening visual field, reportedly elevated intraocular pressure (IOP), and an afferent pupillary defect. Her previous exam was 3 weeks earlier and she had been previously referred to an ophthalmologist over a year earlier by another optometrist, but her mother did not know why and did not take her. When presented with painless vision loss in a young patient with these findings, there are numerous diagnostic possibilities.

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Case Challenge 01 – June 2018

A 27 year old woman presents urgently complaining of painful vision loss in her right eye. She has no known medical history and this has never occurred before. She has an edematous optic nerve with hemorrhaging, an afferent pupil defect, superior arcuate scotoma, pain when she moves her eye, and 20/70 visual acuity. A clear-cut case of optic neuritis possibly as the first manifestation of multiple sclerosis? Perhaps…perhaps not.

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Mid-Winter Education Getaway

Scottsdale, AZ
February 15 – 17, 2019


Quebec City, Quebec, Canada
June 28 – 30, 2019

Music City Fall Classic

Nashville, TN
November 1 – 3, 2019