Paralysis of accommodation with preserved pupillary function as the initial manifestation of Guillain-Barré syndrome.

A 7-year-old boy who complained of blurred reading vision was found on ophthalmologic examination to have subnormal distance visual acuity in both eyes and a hyperopic refractive error that was deemed too small to explain his symptoms. Within days, he developed speech and gait deficits that led to a diagnosis of Guillain-Barré syndrome (GBS). Inpatient examination confirmed a profound binocular loss of accommodation with preservation of iris sphincter function and eye movements. This is only the second detailed report of accommodative loss with sparing of the pupil as the initial clinical manifestation of GBS.