title: Taurine deficiency is a cause of vigabatrin-induced retinal phototoxicity.
abstract: OBJECTIVE
  Although vigabatrin irreversibly constricts the visual field, it remains a potent therapy for infantile spasms and a third-line drug for refractory epilepsies. In albino animals, this drug induces a reduction in retinal cell function, retinal disorganization, and cone photoreceptor damage. The objective of this study was to investigate the light dependence of the vigabatrin-elicited retinal toxicity and to screen for molecules preventing this secondary effect of vigabatrin.
  
  
  METHODS
  Rats and mice were treated daily with 40 and 3mg vigabatrin, respectively. Retinal cell lesions were demonstrated by assessing cell function with electroretinogram measurements, and quantifying retinal disorganization, gliosis, and cone cell densities.
  
  
  RESULTS
  Vigabatrin-elicited retinal lesions were prevented by maintaining animals in darkness during treatment. Different mechanisms including taurine deficiency were reported to produce such phototoxicity; we therefore measured amino acid plasma levels in vigabatrin-treated animals. Taurine levels were 67% lower in vigabatrin-treated animals than in control animals. Taurine supplementation reduced all components of retinal lesions in both rats and mice. Among six vigabatrin-treated infants, the taurine plasma level was found to be below normal in three patients and undetectable in two patients.
  
  
  CONCLUSIONS
  These results indicate that vigabatrin generates a taurine deficiency responsible for its retinal phototoxicity. Future studies will investigate whether cotreatment with taurine and vigabatrin can limit epileptic seizures without inducing the constriction of the visual field. Patients taking vigabatrin could gain immediate benefit from reduced light exposures and dietetic advice on taurine-rich foods.
authors.affiliation: Institut National de la Sante et de la Recherche Médicale, U592, Institut de la Vision, Paris, France.
authors.forename: Firas
authors.initials: F
authors.lastname: Jammoul
authors.forename: Qingping
authors.initials: Q
authors.lastname: Wang
authors.forename: Rima
authors.initials: R
authors.lastname: Nabbout
authors.forename: Caroline
authors.initials: C
authors.lastname: Coriat
authors.forename: Agnès
authors.initials: A
authors.lastname: Duboc
authors.forename: Manuel
authors.initials: M
authors.lastname: Simonutti
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Dubus
authors.forename: Cheryl M
authors.initials: CM
authors.lastname: Craft
authors.forename: Wen
authors.initials: W
authors.lastname: Ye
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Collins
authors.forename: Olivier
authors.initials: O
authors.lastname: Dulac
authors.forename: Catherine
authors.initials: C
authors.lastname: Chiron
authors.forename: José A
authors.initials: JA
authors.lastname: Sahel
authors.forename: Serge
authors.initials: S
authors.lastname: Picaud
mesh_terms: D000596:Amino Acids / Q000097:blood; D000704:Analysis of Variance; D000818:Animals; D002675:Child, Preschool; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004596:Electroretinography / Q000379:methods; D004791:Enzyme Inhibitors / Q000009:adverse effects*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006801:Humans; D007211:Indoles; D007223:Infant; D051379:Mice; D010787:Photosensitivity Disorders / Q000150:complications / Q000188:drug therapy / Q000209:etiology*; D051381:Rats; D012160:Retina / Q000473:pathology; D012164:Retinal Diseases / Q000188:drug therapy / Q000209:etiology* / Q000378:metabolism* / Q000473:pathology; D013223:Statistics as Topic; D013654:Taurine / Q000097:blood / Q000172:deficiency* / Q000627:therapeutic use; D020888:Vigabatrin / Q000009:adverse effects* / Q000627:therapeutic use
chemical_list: D000596:Amino Acids; D004791:Enzyme Inhibitors; D005904:Glial Fibrillary Acidic Protein; D007211:Indoles; D013654:Taurine; C007293:DAPI; D020888:Vigabatrin