• Medication used to treat seizures and migraine
  • Most common ophthalmic side effect: angle-closure glaucoma caused by edema of the ciliary body
  • Incidence of this side effect estimated at 2%
  • Avoid prescribing topiramate if ophthalmologist has documented that patient has narrow anterior chamber angle
  • Refer emergently to ophthalmologist any patient with acute eye pain or visual symptoms who is taking topiramate
  • Discontinue topiramate if angle closure glaucoma is confirmed
  • Intraocular pressure must be lowered promptly with aqueous suppressants, cycloplegia, topical corticosteroids
  • Peripheral iridectomy, standard approach to angle closure glaucoma not caused by topiramate, does not work here
  • Permanent vision loss has resulted from angle closure precipitated by topiramate even when diagnosis and treatment are undertaken promptly