Topiramate is known to cause ocular side effects such as refractive changes and angle closure. We describe a patient with
an electronegative electroretinogram (ERG) which may have been related to topiramate use. Electronegative ERG’s have been
associated with other drugs in humans as well as topiramate use in rabbits. However, this would be the first suggestion of
causality in humans.
Keywords Electronegative - Electroretinogram - Topiramate - Topamax - Best disease - Vitelliform maculopathy