Topiramate-induced ocular side effects in Egyptian patients, idiosyncratic versus dose-dependent effect, a prospective study

Abstract

Background: To test the nature of the ocular side effects induced by topiramate (TPM) whether dose dependent or idiosyncratic, and to test various predictors that might influence the occurrence of those side effects. Methods: Twenty patients treated with TPM were included in this study. Patients underwent ophthalmic assessment before and after 4 weeks of treatment by stable doses of oral TPM. We examined non-cycloplegic refraction (RF) in diopters, best corrected visual acuity (BCVA), intraocular pressure (IOP) in mmHg, and anterior chamber depth (ACD) in mm. Results: There were no statistically significant differences between baseline and follow-up assessments in all tested ophthalmological parameters including errors of RF, ACD, IOP, and the BCVA. One case suffered from painful drop of vision in both eyes with elevated IOP and decreased ACD, and evident myopic shift 1 week after treatment with small dose of TPM. There was no significant effect of age, TPM dose, disease, and gender on all tested variables. Conclusion: TPM can induce idiosyncratic, but not dose dependent, ocular side effects, namely myopic shifts and angle closure glaucoma. Those side effects were not disease, age, or gender dependent. However, ethnicity might play a role in induction of those side effects.