Teaching Video NeuroImage: Tadpole Pupil.

A 27-year-old healthy woman reported short episodes (15-30 seconds) of unilateral blurred vision in the left eye, during which an irregular shape of her left pupil was observed. She had no other symptoms. At presentation, pupils were equal in size and reactive to light, and there was no dilation lag, no eyelid ptosis, and eye motility was full. Diagnosis of tadpole pupil was made based on photographs taken by the patient herself (Figure) (Video 1). Because of a close association with Horner syndrome, sympathetic denervation hypersensitivity has been considered as an underlying mechanism. However, pharmacologic testing was negative (both cocaine 10% and apraclonidine 0.5%).