Visual field constriction and antiepileptic drug treatment

Several reports concerning visual field constriction associated with antiepileptic drug treatment have been published within the last years. In the investigation of concentric field changes associated with antiepileptic drugs, a variety of additional factors have to be excluded. Concerning antiepileptic drugs, visual field defects (VFD) have been observed during phenytoin, diazepam, carbamazepine, tiagabine, gabapentin, and vigabatrin treatment. The true frequency of all VFD in epilepsy population is unknown. This stimulated a retrospective study at our department to investigate the frequency of visual field defects in a series of 158 patients with partial epilepsy. VFD could be detected in 21 patients (13 %) according to Goldmann perimetry. 13 patients (8 %) had a concentric visual field constriction without subjective spontaneous manifestations. Of these 13 patients, 9 (69 %) were treated with vigabatrin, 4 (31 %) of them at the time of the Goldmann-perimeter testing, and 4 (31 %) patients never received vigabatrin, Patients in our collective were treated with up to 11 different antiepileptic drugs - a causal relationship is therefore difficult to establish. There was no relationship to the etiology of epilepsy. Lesions in the visual system caused, as expected, anopsies to the contralateral side.