Peripheral visual field defect of vigabatrin in pediatric epilepsy: A review

Abstract

Vigabatrin is the medication used for the treatment of infantile spasms and refractory complex partial seizures, but its usage has always been contradictory due to its effect on vision. This review focuses on the registry, mechanism of injury, animal study, pharmacokinetics, risk factors, efficacy, safety and precautions of vigabatrin. The first visual defect with vigabatrin use was detected in 1997. This led to initiation of many trials including compulsory registration of patients in Sabril registry. The site of toxicity is found to be inner retina where vigabatrin tends to inhibit densely gamma amino butyric acid-C (GABA-C) receptors resulting in intoxication of visual field and also genetic variations held responsible for the injury. The toxicological studies of vigabatrin on various animals reveal different physiology, deficiency of taurine and light can effect on visual field and its related cells. Only thing need to be monitored with use of vigabatrin is visual field because it is well absorbed, with zero protein binding and no necessary dosage adjustment. The effect of vigabatrin is seen to vary with age, duration of therapy, cumulative dose and gender. The efficacy differs in various studies for different forms of epilepsy and so does the safety. Precautions are needed to be followed regarding use of vigabatrin by considering the risk versus benefit ratio for each and every individual and also discussing with the patient’s caregivers. The ultimate goal in treating with vigabatrin for any form of epilepsy is the good clinical response.