Color vision in epilepsy patients treated with vigabatrin or carbamazepine monotherapy.
OBJECTIVE
To investigate color vision in epilepsy patients treated with vigabatrin or carbamazepine monotherapy and to evaluate the association between vigabatrin-induced visual field defects and dyschromatopsia.


METHODS
Nonrandomized comparative trial.


METHODS
Thirty-two epilepsy patients treated with vigabatrin monotherapy, 18 patients treated with carbamazepine monotherapy, and 47 age-matched healthy controls were examined.


METHODS
Color vision was examined with Standard Pseudoisochromatic Plates 2 (SPP2) screening test, Farnsworth-Munsell 100 (FM 100) hue test, and Color Vision Meter 712 anomaloscope.


RESULTS
Abnormal color perception was found in 32% of the epilepsy patients treated with vigabatrin monotherapy and 28% of the epilepsy patients treated with carbamazepine monotherapy. The total error score in the Farnsworth-Munsell 100 hue test was abnormally high in the vigabatrin monotherapy patients who had concentrically constricted visual fields and a statistically significant correlation was found between the temporal visual field extents and the age-adjusted Farnsworth-Munsell 100 total error score in vigabatrin monotherapy patients (R = .533, P = 0.003 in the right eye, R = .563, P = 0.001 in the left eye). Four of 31 (12%) vigabatrin monotherapy patients, and 1 of 18 (6%) carbamazepine monotherapy patients had a blue axis in Farnsworth-Munsell 100 hue test. In the anomaloscope, there were a few pathologic findings in both groups. In the SPP2 screening test, a few plates were not seen in both groups.


CONCLUSIONS
Both examined antiepileptic drugs, vigabatrin and carbamazepine, cause acquired color vision defects. The abnormal color perception seems to be associated with constricted visual fields in the vigabatrin monotherapy patients. The duration of carbamazepine therapy correlates with high FM100 total error score. The best method for detecting dyschromatopsia in patients treated with vigabatrin or carbamazepine was the Farnsworth-Munsell 100 hue test. The SPP2 screening test does not seem to be useful in clinical practice.
Nousiainen
I
I
Department of Ophthalmology, Kuopio University Hospital, Finland.
Kälviäinen
R
R
Mäntyjärvi
M
M
D000328:Adult; D000368:Aged; D000927:Anticonvulsants / Q000009:adverse effects* / Q000627:therapeutic use; D002220:Carbamazepine / Q000009:adverse effects* / Q000627:therapeutic use; D003118:Color Perception / Q000187:drug effects* / Q000502:physiology; D003119:Color Perception Tests; D003117:Color Vision Defects / Q000139:chemically induced* / Q000503:physiopathology; D004827:Epilepsy / Q000188:drug therapy* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020888:Vigabatrin / Q000009:adverse effects* / Q000627:therapeutic use; D014794:Visual Fields / Q000187:drug effects
D000927:Anticonvulsants; D002220:Carbamazepine; D020888:Vigabatrin