Detecting the unexpected: Adie’s tonic pupil

ABSTRACT

Adie’s tonic pupil is a benign efferent pupillary defect, usually unilateral, in which a larger-than-normal pupil responds minimally if at all to light but constricts slowly and tonically to a near stimulus (light-near dissociation). A 28-year-old female presented with vague symptoms of discomfort in the right eye initially, with normal ocular findings. She gradually developed diminished vision for far and near and presented with symptoms of anisocoria, dilated pupil not responding to light, constricting slowly to near reflex, confirmed by dilute pilocarpine test. However, such a pupillary sign does not necessarily indicate a severe central nervous system process, especially if there is no other associated neurological sign. It is essential to improve understanding of the disease to avoid misdiagnosis.