title: [Oxygen saturation of retinal vessels. Studies for measuring with polarized light].
abstract: The accuracy of the spectrometric measurement of the oxygen saturation in retinal vessels is limited by its signal-to-noise ratio. The aim of this study was to investigate the possibility of enhancement of the reflection signal by the use of polarized light.
  
  
  METHODS
  The Jena ophthalmospectrometer was equipped with two polarizing filters: one in the illumination and the other in front of the detector. Reflection spectra of erythrocytes streaming through a cuvette in the focus of an artificial eye were recorded. The influence of the polarization on the reflection spectra was investigated by rotating the polarizer in front of the detector. Furthermore, the degree of polarization of the light reflected from retinal vessels in vivo was determined.
  
  
  RESULTS
  The degree of polarization of the light reflected from the erythrocytes was 0.6-0.8, whereas the polarization of light reflected by a standard white reflectance target was virtually zero.
  
  
  CONCLUSIONS
  Polarized light can be used for the reduction of error in retinal vessel oximetry.
authors.affiliation: Klinik für Augenheilkunde der Friedrich Schiller-Universität Jena.
authors.forename: M
authors.initials: M
authors.lastname: Hammer
authors.forename: D
authors.initials: D
authors.lastname: Schweitzer
authors.forename: A
authors.initials: A
authors.lastname: Kolb
authors.forename: E
authors.initials: E
authors.lastname: Thamm
authors.forename: J
authors.initials: J
authors.lastname: Strobel
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology; D004912:Erythrocytes / Q000378:metabolism; D005654:Fundus Oculi; D006400:Hematocrit; D006801:Humans; D019721:Ophthalmoscopes; D055095:Optics and Photonics; D010100:Oxygen / Q000097:blood*; D019047:Phantoms, Imaging; D012016:Reference Values; D012171:Retinal Vessels / Q000502:physiology*; D013057:Spectrum Analysis / Q000295:instrumentation*
chemical_list: D010100:Oxygen