To report a case of bilateral optic disc edema associated with hypocalcemia.

A 48-year-old woman visited our ophthalmology department with decreased vision and disturbance of the visual field in the right eye, which began 2 days prior to presentation. The patient history indicated she had undergone total thyroidectomy 3 months prior and was given an oral calcium preparation. She had no eye pain, headache, tinnitus or diplopia. Her best corrected visual acuity of both eyes was 1.0, and color vision was normal in both eyes although a mild relative afferent pupillary defect was present in the right eye. Severe bilateral optic disc edema was present in the right eye. A Humphrey visual field test revealed an enlarged blind spot and peripheral nasal step scotoma in the right eye. The Cerebrospinal fluid (CSF) opening pressure was within the normal range and there were no abnormal findings regarding CSF. Additionally, there were no remarkable findings on brain magnetic resonance imaging nor neurologic tests. Her serum calcium was 5.9 mg/dL (normal range: total calcium 8.7-10.6 mg/dL), and an intravenous calcium supplement was started. Visual disturbance and optic disc edema improved 2 days after replacement and the optic disc edema completely dissolved 2 months later.

Hypocalcemia may cause bilateral optic disc edema and can be recovered through adequate calcium supplementation, and it is necessary to prevent and promptly detect this rare complication.