Topiramate-Induced Changes in Anterior Chamber Angle and Choroidal Thickness

Purpose: To investigate the acute effects of topiramate on the anterior chamber angle (ACA) and choroidal thickness in patients with migraine. Methods: This prospective study included 15 eyes of 15 patients with migraine who have been scheduled to start topiramate therapy. All patients underwent complete ophthalmic examination including measurement of the ACA and choroidal thickness using a spectral domain optical coherence tomography device (Optovue Inc.) and refractive status evaluation with an autorefractokeratometer (KR-8100; Topcon) at the baseline and 1 week after starting therapy. The patients were asked to report any pain or discomfort in their eyes during therapy at the follow-up visit. Results: None of the patients experienced pain or discomfort in their eyes. The mean ACA significantly decreased at the first week of the therapy compared with the baseline levels (40.34 +/- 7.06 degrees and 36.89 +/- 6.87 degrees, respectively) (P=0.001). However, the mean choroidal thickness increased from 277.33 +/- 95.60 mu m at the baseline to 323.40 +/- 84.50 mu m at the first week (P=0.01). There was a nonsignificant increase in the mean refractive error (from -0.25 +/- 0.54 diopter [D] at the baseline to -0.38 +/- 0.49 D after 1 week) (P=0.06). Conclusions: Topiramate can acutely decrease the ACA and increase the choroidal thickness. Because these effects may be asymptomatic, patients with migraine who start this therapy should be warned to be closely followed up by an ophthalmologist.