Neuro-ophthalmologic examination, visual field examination and visual-evoked potential test of the patient. (A) Retinal photograph showed a normal fundus. (B) Optical coherence tomography was normal. OD, right eye; OS, left eye. (C) A visual field examination showed an irregular visual field defect in both eyes. (D) Visual-evoked potentials disclosed a mild prolongation of P100 latency of the left eye and an increased amplitude of both eyes.