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A Multimodal Imaging- and Stimulation-based Method of Evaluating Connectivity-related Brain Excitability in Patients with Epilepsy
Published on: November 13, 2016
Color vision and contrast sensitivity in epilepsy patients treated with initial tiagabine monotherapy
Iiris Sorri1, Reetta Kälviäinen, Maija Mäntyjärvi
1Department of Ophthalmology, Kuopio University Hospital, P.O. Box 1777, FIN-70211 Kuopio, Finland; Department of Ophthalmology, University of Kuopio, Kuopio, Finland. Iiris.Sorri@uku.fi
Abstract:
The purpose of the study was to determine whether the use of a GABAergic antiepileptic drug (AED), tiagabine, affects color vision and contrast sensitivity. Twenty newly diagnosed patients with partial epilepsy (aged 19-72 years), receiving tiagabine as their initial monotherapy for 5-41 months were examined. Color vision was examined with the Standard Pseudoisochromatic Plates 2 (SPP2), with the Farnsworth-Munsell 100 Hue Test (FM100) and with the Color Vision Meter 712 (CVM) anomaloscope. Contrast sensitivity was measured with the Pelli-Robson letter chart. Three patients excluded from the color vision evaluation for congenital red-green color vision defects. Seven out of 17 patients (41%) had acquired color vision deficit examined with the FM100. The CVM anomaloscope revealed minor defects in two patients. Contrast sensitivity function was within normal ranges. The present study suggests that AED therapy with tiagabine, like with other established and newer AEDs may interfere with color perception.
Insights
This study found that tiagabine, an antiepileptic drug (AED), may negatively impact color vision in epilepsy patients. While contrast sensitivity remained normal, acquired color vision deficits were observed in 41% of participants.
Area of Science:
- Neuroscience
- Ophthalmology
- Pharmacology
Background:
- Epilepsy is a neurological disorder often treated with antiepileptic drugs (AEDs).
- Some AEDs are known to cause visual side effects.
- Tiagabine is a GABAergic AED used for partial epilepsy.
Purpose of the Study:
- To investigate the effects of tiagabine monotherapy on color vision and contrast sensitivity in epilepsy patients.
- To determine if tiagabine use is associated with acquired color vision deficits.
Main Methods:
- Evaluated 20 newly diagnosed partial epilepsy patients on tiagabine monotherapy (5-41 months).
- Assessed color vision using Standard Pseudoisochromatic Plates 2 (SPP2), Farnsworth-Munsell 100 Hue Test (FM100), and Color Vision Meter 712 (CVM) anomaloscope.
- Measured contrast sensitivity with the Pelli-Robson letter chart.
Main Results:
- Seven out of 17 patients (41%) exhibited acquired color vision deficits on the FM100 test.
- Minor color vision defects were detected in two patients using the CVM anomaloscope.
- Contrast sensitivity function remained within normal ranges for all participants.
Conclusions:
- Tiagabine therapy, similar to other AEDs, may interfere with color perception.
- Acquired color vision deficits are a potential side effect of tiagabine treatment.
- Further research is warranted to understand the mechanisms and clinical significance of tiagabine-induced visual disturbances.
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