A significant drug-drug interaction detected through corneal examination: resolution of cornea verticillata while using amiodarone.

Purpose: To describe a patient with resolution of cornea verticillata while still using amiodarone as a result of a drug interaction lowering serum levels of amiodarone.
Methods: An 83-year-old retired physician with long-standing cornea verticillata was noted to have complete resolution of cornea verticillata on a routine follow-up eye examination. The patient reported complete compliance with using amiodarone daily, with no recent changes in dosage or formulation. Despite this, he reported a recent increase in the frequency of palpitations. He had recently started rifampin for treatment of tuberculosis.
Results: Serum amiodarone and desethylamiodarone levels were obtained and found to be below therapeutic range. After rifampin was discontinued, serum amiodarone and desethylamiodarone levels increased to a therapeutic range and cornea verticillata returned after 4 months.
Conclusions: In patients currently using amiodarone, clearing of cornea verticillata should alert the ophthalmologists to the possibility of decreased serum amiodarone levels.