case report: we describe a 42 year-old patient who developed acute myopia and closed-angle glaucoma one week after beginning treatment with topiramate. ultrasound biomicroscopy revealed a bilateral angle closure and choroidal effusion. the clinical findings resolved with withdrawal of the topiramate. discussion: topiramate may cause acute myopia and closure angle glaucoma in some patients due to a choroidal effusion. ultrasound biomicroscopy seems to be a useful tool for monitoring the progression of the clinical lesions and their resolution when the drug is withdrawn.