Methods: Six rabbits were treated with a daily oral dose of topiramate orally during a period of eight months. Six rabbits receiving water served as controls. Blood samples were analyzed for determination of topiramate serum levels in order to ensure successful drug exposition.Standardized full-field electroretinograms (ERGs) were performed before treatment and then at 2, 3 and 8 months during the treatment period. After terminating treatment the rabbits were sacrificed and the morphology of the sectioned retina was studied. The retinal dysfunction and the morphological changes indicate that topiramat may damage the retina, similarly to vigabatrin (another anti-epileptic drug).