Visual field defect during therapy with valproic‐acid

Visual field defect because of antiepileptic drug (AED) treatment has been widely reported during the clinical application of vigabatrin. But other gamma-aminobutyric acid (GABA)-ergic and non-GABA-ergic AEDs could also affect the visual field with different mechanisms of action. Here we report a case of a 22-year-old female patient, who suffered from bilateral concentric visual field defect during the long-term therapy with valproic-acid (VPA). A VPA-related metabolic dysfunction was found through blood and urine examination. Reduced B-waves were shown by electroretinography and a bilateral concentric visual field defect was confirmed by both manual and automated perimetry. In conclusion, the concentric visual field defect related to VPA treatment is rare but possible.