Persistent pseudomyopia following a whiplash injury in a previously emmetropic woman

Accommodative spasm, which manifests as ciliary muscle spasm, convergent strabismus or miosis, is a recognised consequence of head trauma. In whiplash cases, cervical spine hyperextension poses a risk of contra-coup injury and brainstem trauma, and is known to affect the visual system. However, to date, no cases of accommodative spasm due to whiplash injury have been reported.

We present the case of a 34-year-old female who developed sudden onset blurred distance vision after a rear impact car crash, having previously been emmetropic. Her unaided distance visual acuity was 20/70 in the right eye and 20/20 in the left. Best-corrected visual acuity in the right eye was 20/20 with a correction that progressed from -1.75 to -3.50 DS over the 12 months following the accident.This patient's sudden unilateral myopia, with unilaterally increased amplitude of accommodation suggests pseudomyopia due to accommodative spasm. Magnetic resonance imaging showed no evidence of injury to her brain stem, frontal lobes or oculomotor nerve. The patient is now well adjusted with a -3.50DS corrective lens for the right eye.

The accommodation reflex is susceptible to injury at the occipital lobe, frontal eye fields, Edinger-Westphal nuclei and oculomotor nerves. As such it should be examined in patients who present with visual disturbances following whiplash injury.It is important that such cases are identified at presentation, as early intervention can improve outcomes in accommodative spasm and reduce the long term psychological effects often associated with whiplash injuries.