The Ophthalmic Side Effects of Topiramate: A Review

Abstract

Topiramate (TPM) is a sulfonamide drug with multiple modes of action. It inhibits carbonic anhydrase, blocks sodium channels, enhances potassium channels, and stimulates postsynaptic gamma-aminobutyric acid (GABA) receptors. Pharmacists Joe Gardocki and Bruce Maryanoff synthesized TPM for the first time in 1979. The FDA did not approve it for medical use in the US until 1996. Around 2004, it was authorized for the prevention of migraine headaches. TPM, like any medication, has several side effects. Common aftermaths include weight loss, diarrhea, dizziness, sleepiness, fatigue, and coordination issues. Some people may experience mental health issues like memory problems, confusion, and speech or language difficulties. The most well-known ocular side effects of TPM are choroidal effusion syndrome, angle-closure glaucoma, and myopic shift. Aside from these, other ophthalmic adverse effects may arise in some people, including retinal problems, uveitis, visual field defects, myokymia, and neuro-ophthalmology complications. If such complications are not identified and treated promptly, they can be severe and vision-threatening, potentially leading to permanent blindness. TPM's application as a standalone and adjunctive therapy has increased over time. In 2019, more than 10 million prescriptions of TPM were issued. Due to its extensive use, medical professionals and patients must be aware of its potential repercussions, especially ophthalmic issues. The current review paper likewise makes a step in this direction. This article's primary purpose is to educate readers by providing a comprehensive assessment of the research on TPM's ocular side effects. All the information has been collected via a thorough search of the Google Search Engine and PubMed.

Analysis of choroidal thickness on optical coherence tomography in a patient with sudden‐onset bilateral myopia, macular striae, and shallow anterior chamber after topiramate use

“…Some cases develop secondary angle closure glaucoma responding to topical atropine rather than peripheral iridotomy 1 . Posterior segment adverse events include retinal striae, macular pigmentary changes, subretinal fluid, 1 choroidal folds, choroidal detachment, and vitritis 2 . The etiology of macular striae after topiramate use may involve choroidal effusion or traction over the macula due to forward traction on the vitreous body caused by the forward shift of the iris‐lens diaphragm.…”

“…However, the OCT showed increased choroidal thickness at the presentation with dilation of medium and large choroidal vessels. It is known that drug‐induced ciliary effusion can cause myopia without causing glaucoma or a rise in intraocular pressure 2 …”

“…It is known that drug-induced ciliary effusion can cause myopia without causing glaucoma or a rise in intraocular pressure. 2 In conclusion, a patient with macular striae and acute onset myopia due to topiramate intake is presented.…”

“… 1 Posterior segment adverse events include retinal striae, macular pigmentary changes, subretinal fluid, 1 choroidal folds, choroidal detachment, and vitritis. 2 The etiology of macular striae after topiramate use may involve choroidal effusion or traction over the macula due to forward traction on the vitreous body caused by the forward shift of the iris‐lens diaphragm. The retinal striae usually resolve after stopping topiramate though systemic steroid has also been tried.…”

“…It is known that drug‐induced ciliary effusion can cause myopia without causing glaucoma or a rise in intraocular pressure. 2 …”