Acute Myopic Shift and Change in Anterior Chamber Depth after Intake of Zonisamide

ABSTRACT

Purpose@#To report a case of acute myopic change and anterior chamber depth decrease induced by zonisamide, which is an antiepileptic drug.Case summary: A 40-year-old male with no ophthalmologic history, who was admitted to the neurology department through the emergency center for evaluation and treatment of frontal lobe epilepsy, was referred to the ophthalmology department due to a visual disturbance that occurred while the patient was being treated with 100 mg of zonisamide during hospitalization. Corrected visual acuities with the patient’s own glasses were 0.3 in both eyes, with intraocular pressure of 16 and 17 mmHg in the right and left eye, respectively. Automated refraction revealed a bilateral myopic change of -1.25 diopters (D) in the right eye and -1.00 D in the left eye, and the anterior chambers in both eyes were shallow under slit-lamp examination. As we assumed these symptoms were related to the intake of zonisamide, we immediately instructed the patient to discontinue the drug. At 3 days after discontinuing the drug, his myopia improved, and corrected visual acuities with the previous glasses increased to 1.0 in both eyes. @*Conclusions@#Zonisamide is a sulfonamide anticonvulsant that may cause acute myopic shift and a reduction in the anterior chamber depth. Therefore, physicians must consider the possibility of these complications occurring, when diagnosing a sudden blurring of vision in patients who are taking sulfonamide medications.