title: [Development and preliminary results of a chromatic illumination system for indirect ophthalmoscopes].
abstract: OBJECTIVE
  Chromatic contrast is a technique used in some areas of medicine to provide better visualization of biological tissues. Based on principles of color composition, a new illumination system was constructed using colored emitting diodes to reproduce the spectral range of visible light. This technique was devised to be used in indirect ophthalmoscopes to improve the visualization of the posterior segment of the eye.
  
  
  METHODS
  The original illumination system of a general purpose indirect ophthalmoscope was substituted by a system of color-emitting diodes.
  
  
  RESULTS
  Using an electronic interface it was possible to control the intensity of the color lights and therefore generate different wavelengths in the visible spectrum of the light. Preliminary tests undertaken in a mechanical model of the human eye generated very clear and homogenous colors. However in vivo examinations with patients were performed in our laboratory at the IFSC-USP and UNIFESP, and obtained the preliminary results show the possibilities of the chromatic contrast technique, and may represent in the future a differential in the analyses of the posterior segment of the eye.
  
  
  CONCLUSIONS
  The use of color-emitting diodes to reproduce the spectral range of the visible light in indirect ophthalmoscopes seems to be a promising technological advance in the fundoscopy of the eye. This is an innovation that can yield better quality examinations with indirect ophthalmoscopes.
authors.affiliation: Universidade Federal de São Carlos, SP, Brasil. thiagobelini@hotmail.com
authors.forename: Thiago Bellini
authors.initials: TB
authors.lastname: Oliveira
authors.forename: Luis Carlos
authors.initials: LC
authors.lastname: Trevelin
authors.forename: Fernando Manoel Araújo
authors.initials: FM
authors.lastname: Moreira
authors.forename: Vanderlei Salvador
authors.initials: VS
authors.lastname: Bagnato
authors.forename: Paulo
authors.initials: P
authors.lastname: Schor
authors.forename: Luis Alberto Vieira de
authors.initials: LA
authors.lastname: Carvalho
mesh_terms: D003116:Color; D004867:Equipment Design; D005654:Fundus Oculi; D006801:Humans; D008029:Lighting / Q000379:methods*; D019721:Ophthalmoscopes; D009887:Ophthalmoscopy / Q000379:methods*