title: Investigation of new dyes for chromovitrectomy: preclinical biocompatibility of trisodium, orangell and methyl violet.
abstract: OBJECTIVE
  To investigate the retinal toxicity by electroretinography (ERG), clinical examination and histology after intravitreal injection of biological stains in two concentrations: Trisodium (0.50 g/L and 1.00 g/L), Orangell (0.25 g/L and 1.00 g/L) and Methyl Violet (0.50 g/L and 1.00 g/L).
  
  
  METHODS
  Eighteen New-Zealand albinos rabbits were assigned in six groups (n = 3 in each group). The animals in group 1 received Trisodium in the dose of 0.50 g/L and group 2 received 1.00 g/L; Group 3 received Orangell in the dose of 0.25 g/L and group 4 received 1.00 g/L; Group 5 received Methyl Violet in the dose of 1.00 g/L and group 6 received 0.50 g/L. A volume of 0.05 mL of dye was injected in the right eyes, whereas the left eyes received the same volume of balanced salt solution (BSS) as control. ERG recordings and clinical examination were performed at baseline and seven days after intravitreal injection. The ERG responses at one week after injection were compared with baseline levels. A decrease in the post-injection amplitude of more than 50% was considered remarkable. After the 7-day follow-up, rabbits were euthanized and eye enucleated for light microscopy (LM) histological evaluation.
  
  
  RESULTS
  At clinical examination by indirect ophthalmoscopy seven days after dye injection, all eyes were negative for cataract, hemorrhage, retinal detachment, and intraocular opacities. Amplitude analysis of maximum scotopic b-wave showed no significant reduction in either dye injected or control eyes. Neither dye nor BSS caused significant retinal alteration on LM at doses tested.
  
  
  CONCLUSIONS
  Trisodium, Orangell and Methyl Violet can be applied in future studies in order to prove the capacity to stain preretinal tissues and vitreous without toxicity. The three dyes did not induce significant ERG amplitude reduction or LM alterations in this preliminary experimental research. Trisodium, Orangell and Methyl Violet may be potentially useful vital dyes for ocular surgery, and deserve further investigation.
authors.affiliation: grid.411249.b0000000105147202Department of Ophthalmology, Federal University of São Paulo, 821 Botucatu Street, 1st floor, Sao Paulo, CEP Brazil.
authors.forename: Emmerson
authors.initials: E
authors.lastname: Badaro
authors.affiliation: grid.411249.b0000000105147202Department of Ophthalmology, Federal University of São Paulo, 821 Botucatu Street, 1st floor, Sao Paulo, CEP Brazil.
authors.forename: Rodrigo A
authors.initials: RA
authors.lastname: Souza-Lima
authors.affiliation: grid.411249.b0000000105147202Department of Ophthalmology, Federal University of São Paulo, 821 Botucatu Street, 1st floor, Sao Paulo, CEP Brazil.
authors.forename: Eduardo A
authors.initials: EA
authors.lastname: Novais
authors.affiliation: grid.411249.b0000000105147202Department of Ophthalmology, Federal University of São Paulo, 821 Botucatu Street, 1st floor, Sao Paulo, CEP Brazil.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Maia
authors.affiliation: grid.411249.b0000000105147202Department of Ophthalmology, Federal University of São Paulo, 821 Botucatu Street, 1st floor, Sao Paulo, CEP Brazil.
authors.forename: Flávio
authors.initials: F
authors.lastname: Hirai
authors.affiliation: grid.10388.320000000122403300Department of Ophthalmology, University of Bonn, Bonn, Germany.
authors.forename: Carsten H
authors.initials: CH
authors.lastname: Meyer
authors.affiliation: grid.411249.b0000000105147202Department of Ophthalmology, Federal University of São Paulo, 821 Botucatu Street, 1st floor, Sao Paulo, CEP Brazil.
authors.forename: Michel Eid
authors.initials: ME
authors.lastname: Farah
authors.affiliation: grid.411249.b0000000105147202Department of Ophthalmology, Federal University of São Paulo, 821 Botucatu Street, 1st floor, Sao Paulo, CEP Brazil.
authors.forename: Eduardo B
authors.initials: EB
authors.lastname: Rodrigues
keywords: Chromovitrectomy; ERG; Eletroretinography; Methyl violet; Orangell; Retina; Toxicity; Trisodium; Vitretomy