title: In vivo toxicity testing of methyl blue and aniline blue as vital dyes for intraocular surgery.
abstract: OBJECTIVE
  To investigate the biocompatibility of methyl blue and aniline blue as vital dyes for vitreoretinal surgery in an in vivo rat model and to evaluate the effect of these dyes on retinal structure and function.
  
  
  METHODS
  Adult Brown-Norway rats received intravitreal injections of 0.1%, 0.2%, and 2% methyl blue or aniline blue dissolved in balanced salt solution with balanced salt solution serving as a control. Retinal toxicity was assessed 7 days thereafter by means of retinal ganglion cell counts, light microscopy, and electroretinography.
  
  
  RESULTS
  No significant decrease in retinal ganglion cell counts at concentrations up to 0.2% was observed. At 2%, however, a significant retinal ganglion cell loss was detected with both dyes (more pronounced for aniline blue). Light microscopy showed no structural changes in the central retina for concentrations up to 0.2%. Electroretinographies detected no adverse effects of methyl blue or aniline blue on rod- or cone-driven responses at concentrations up to 0.2%.
  
  
  CONCLUSIONS
  Methyl blue and aniline blue are very biocompatible and may, therefore, be usable for intraocular surgery. Further testing with other animal models will be necessary to confirm this. The safety margin of methyl blue is possibly higher than that of aniline blue.
authors.affiliation: Centre for Ophthalmology, University of Tuebingen, Tuebingen, Germany. sebastian.thaler@uni-tuebingen.de
authors.forename: Sebastian
authors.initials: S
authors.lastname: Thaler
authors.forename: Frank
authors.initials: F
authors.lastname: Schuettauf
authors.forename: Michal
authors.initials: M
authors.lastname: Fiedorowicz
authors.forename: Andre
authors.initials: A
authors.lastname: Messias
authors.forename: Andreas
authors.initials: A
authors.lastname: Schatz
authors.forename: Tomasz J
authors.initials: TJ
authors.lastname: Choragiewicz
authors.forename: Christian A
authors.initials: CA
authors.lastname: May
authors.forename: Eberhart
authors.initials: E
authors.lastname: Zrenner
authors.forename: Anselm
authors.initials: A
authors.lastname: Kampik
authors.forename: Christos
authors.initials: C
authors.lastname: Haritoglou
mesh_terms: D000814:Aniline Compounds / Q000633:toxicity*; D000818:Animals; D001557:Benzenesulfonates / Q000633:toxicity*; D002452:Cell Count; D004396:Coloring Agents / Q000633:toxicity*; D004596:Electroretinography / Q000187:drug effects; D005456:Fluorescent Dyes / Q000633:toxicity*; D007267:Injections; D008297:Male; D051381:Rats; D011914:Rats, Inbred BN; D012160:Retina / Q000187:drug effects* / Q000473:pathology / Q000601:surgery; D012165:Retinal Ganglion Cells / Q000187:drug effects* / Q000473:pathology; D014822:Vitreous Body
chemical_list: D000814:Aniline Compounds; D001557:Benzenesulfonates; D004396:Coloring Agents; D005456:Fluorescent Dyes; C017006:aniline blue; C414357:Methyl Blue