title: Evaluation of Ocular Side Effects in the Patients on Topiramate Therapy for Control of Migrainous Headache.
abstract: BACKGROUND
  Topiramate, a sulfa-derivative monosaccharide, is an antiepileptic drug which is administered in the control of migraine. It is reported to cause various ocular side effects such as visual field defect and myopic shift. To investigate the alterations in refractive error, properties of the cornea and changes in the anterior chamber in patients that receive Topiramate for migraine control.
  
  
  METHODS
  This is a hospital-based, non-interventional, observational study that is conducted at Imam Hossein Hospital, affiliated to Shahid Beheshti University of Medical Sciences, Department of Neurology, in collaboration with the department of Ophthalmology. Thirty three consecutive patients with the diagnosis of migraine that were candidate for Topiramate therapy were recruited. Patients with history of ocular trauma or surgery, keratoconus, glaucoma, congenital ocular malformations and any history of unexplained visual loss were excluded. After thorough ophthalmic examination, all the patients underwent central corneal thickness (CCT) measurement, and Pentacam imaging (Scheimpflug camera) at the baseline. Various parameters were extracted and used for analysis. Anterior chamber volume (ACV), anterior chamber depth (ACD), and anterior chamber angle (ACA) measurement was performed. These measurements were repeated on day 30(th) and 90(th) after the initiation of Topiramate therapy. According to the normality tests, parameters with normal distribution were analysed using the repeated measures test and the remaining parameters (with non-normal distribution) were analysed using the non-parametric k-sample test. A p-value< 0.05 was considered statistically significant, according to Bonferroni post hoc correction.
  
  
  RESULTS
  There were 66 eyes of 33 patients under the diagnosis of migrainous headache, that Topiramate was initiated for headache control, included in the study. The mean value of refractive error had a statistically significant myopic change, from -0.23 diopters (D) at the baseline to -0.61 D at the 90(th) day of follow-up period (p-value < 0.001). Mean CCT was 531.43 μm at the baseline and increased to 534.72 μm at the 30(th) day, and 537.51 μm at the 90(th) day after the administration of Topiramate (p-value=0.001). Mean value of other parameters, ACV, ACD, and ACA, did not reveal statistically significant change.
  
  
  CONCLUSIONS
  Myopic shift and gradually increasing CCT in the patients after Topiramate administration should be considered before any refractive surgery. We found no gradual change in the anterior chamber and angle parameters in our patients in the 90 days of follow up. More studies with a longer duration of follow-up are needed to elucidate dose-dependent ocular manifestations.
authors.affiliation: Assistant Professor, Department of Neurology, Imam Hossein Hospital, Shahid Beheshti University of Medical Sciences (SBMU) , Tehran, Iran .
authors.forename: Omid
authors.initials: O
authors.lastname: Hesami
authors.affiliation: Ophthalmologist, Farabi Eye Hospital, Tehran University of Medical Sciences , Tehran, Iran .
authors.forename: Seyedeh Simindokht
authors.initials: SS
authors.lastname: Hosseini
authors.affiliation: Neurologist, Dezful University of Medical Sciences , Dezful, Iran .
authors.forename: Nasim
authors.initials: N
authors.lastname: Kazemi
authors.affiliation: Social Development and Health Promotion Research Center, Kermanshah University of Medical Sciences , Kermanshah, Iran .
authors.forename: Seyed-Mostafa
authors.initials: SM
authors.lastname: Hosseini-Zijoud
authors.affiliation: Assistant Professor, Department of Neurology, Imam Hossein Hospital, Shahid Beheshti University of Medical Sciences (SBMU) , Tehran, Iran .
authors.forename: Nahid Beladi
authors.initials: NB
authors.lastname: Moghaddam
authors.affiliation: Assistant Professor, Department of Neurology, Imam Hossein Hospital, Shahid Beheshti University of Medical Sciences (SBMU) , Tehran, Iran .
authors.forename: Farhad
authors.initials: F
authors.lastname: Assarzadegan
authors.affiliation: Optometrist, Imam Hossein Hospital, Shahid Beheshti University of Medical Sciences (SBMU) , Tehran, Iran .
authors.forename: Sara
authors.initials: S
authors.lastname: Mokhtari
authors.affiliation: Assistant of Neurology, Department of Neurology, Imam Hossein Hospital, Shahid Beheshti University of Medical Sciences (SBMU) , Tehran, Iran .
authors.forename: Shahrzad
authors.initials: S
authors.lastname: Fakhraee
keywords: Anterior chamber depth; Central corneal thickness; Myopic shift