The role of apraclonidine in Horner’s syndrome: A case report

. Horner’s syndrome is an interruption of the sympathetic nervous system at any point along its course between the hypothalamus and the orbit. Horner’s syndrome is classically presented as an ipsilateral miosis, subtle ptosis, and facial anhidrosis. Pharmacologic testing is very useful in the diagnosis of Horner’s syndrome as it could help to localize the lesioned neuron in the sympathetic pathway, suggesting an etiology. Case Outline. We present a case report of a 41-year-old woman who reported right eyelid drooping immediately after operation of sympathetic chain schwannoma. We performed apraclonidine test for the diagnosis of Horner’s syndrome, which produced mydriasis on the affected eye, while there was no significant change of the normal eye. Based on the clinical presentation of anisocoria and one-sided ptosis, and previous medical history of surgical removal of the mediastinal tumor, the patient was diagnosed with a right-sided, partial Horner’s syndrome. Conclusion. Timely recognition, exact localization of the lesioned neuron, and referral for urgent imaging studies are important for ophthalmologists in order to prevent and treat life-threatening conditions. Besides its diagnostic value in Horner’s syndrome, topical apraclonidine could correct ptosis for the sake of esthetics or when ptosis reduces the superior visual field