Visual field constriction in epilepsy patients treated with vigabatrin and other antiepileptic drugs: A prospective study

Background Visual field constriction (VFC) has been described in about 30 % to 50 % of patients treated with the antiepileptic drug (AED) Vigabatrin (GVG). The exact incidence of VFC related to GVG exposure is unknown. Risk factors other than medication have not been identified as yet, and it is unclear whether the occurrence of VFC is restricted to the use of GVG. Methods In a longitudinal study, we investigated 60 epilepsy patients who received GVG and other AEDs. Patients underwent full ophthalmological examination including perimetry. Results 16 of 60 patients exposed to different AEDs developed VFC, which was judged as clinically relevant by an experienced neuroophthalmologist. VFC was observed significantly more often in patients treated with GVG as add-on- or monotherapy as compared with patients who had never been exposed to GVG (13/29 versus 3/31). Within the subgroup of 23 patients who received GVG as add-on therapy, those who developed VFC had been exposed to GVG for significantly longer than patients without VFC. The only non-treatment related feature associated with VFC was older age. Type and severity of epilepsy or type and number of concomitant AED were not related to the occurrence of VFC. Conclusions The findings of an overrepresentation of VFC in patients receiving GVG and of a correlation between duration of GVG treatment and occurrence of VFC support the causal role of GVG treatment in the development of VFC. Old age is a possible risk factor for the development of VFC associated with GVG in epilepsy patients.