Case Report: Topiramate-Associated Bilateral Monocular Diplopia, Palinopsia, and Photopsia

Introduction This case highlights a rare combination of visual disturbances all attributable to topiramate usage. Although each visual disturbance has been individually associated with topiramate, the combination of such visual disturbances has never been reported to our knowledge. The goal of this report is to educate on uncommon, yet serious, visual disturbances associated with topiramate use. Case Report A 33-year-old woman presented with a complaint of oblique monocular diplopia of both eyes individually as well as palinopsia and photopsia of both eyes. The palinopsia only occurred with object movement (e.g., visualizing three or four trailing hand images when moving her hand in front of her). Her uncorrected vision was 20/20 in each eye individually. Manifest refraction yielded 20/15 in the right eye and 20/20 vision in the left eye but did not relieve the monocular diplopia. There was no identifiable binocular vision disorder. Corneal topography demonstrated no corneal irregularities other than a post-LASIK scar. Magnetic resonance imaging of the brain and orbits was unremarkable. Optical coherence tomography of the maculae and optic nerves demonstrated no clear explanation for her complaints. Perimetry revealed no notable defects. With no overt ocular cause of the monocular diplopia, palinopsia, and photopsia, it was decided that the most probable cause of these visual disturbances was the topiramate. Within 1 week of discontinuing topiramate, the monocular diplopia of both eyes, palinopsia, and photopsia had completely resolved. Conclusion This case serves as an example of significant and debilitating visual disturbances that may occur with even low doses of topiramate.