Topiramate induced Acute Myopia and Acute Angle Closure Glaucoma

Arif Adenwala

Topiramate, a new anticonvulsant, is nowadays widely used for the prophylaxis of migraine and cluster headache.
About four cases of Myopia and Glaucoma are discussed in this paper. All the four patients presented to the eye clinic within few days of taking oral Topiramate.

Aim: To describe cases of Bilateral Acute Myopia and Acute Angle Closure Glaucoma after Oral Topiramate.

Case Report: We had four cases taking Oral Topiramate and presenting to the eye clinic within few days. They presented with decrease vision and heaviness after starting the drug. On Slit Lamp examination mild conjunctival congestion in one case and shallow anterior chamber in all the cases were seen. Axial lengths of the eye were normal. On examination they had refractive error ranging from -4 to -10 spherical and pressure in range of 30-50 mm Hg.
Ultra sonography done in one case showed cilio choroidal detachment. The drug was stopped immediately after consultation of the neurologist and anti glaucoma drops were started. On regular follow up IOP got reduced and vision came back to normal.
IOP and Visual Acuity was measured at regular interval after stopping the drug and the eye drops.

Conclusion: Topiramate, an antiepileptic medication very effective for prophylaxis of Migraine, may cause ciliochoroidal detachments and ciliary body edema leading to anterior displacement of the lens-iris diaphragm, lens thickening, and acute angle-closure glaucoma. These effects get corrected once you stop the medication.

Topiramate may cause ciliary body edema and relaxation of zonules, which induces a forward shift of the lens-iris diaphragm with acute myopia and angle closure. As the mechanism of angle closure does not involve pupillary block, peripheral iridectomy and topical miotics are not useful in the treatment of this type of secondary angle-closure glaucoma. The patient improved after topiramate discontinuation.