Imaging spectrometry in ophthalmology--principle and applications in microcirculation and in investigation of pigments

Ophthalmic Res. 1996:28 Suppl 2:37-44. doi: 10.1159/000267955.

Abstract

Imaging spectrometry is a new technique that permits simultaneous measurements of reflectance spectra at different locations along a line. Results are three-dimensional images, whose coordinates are location, wavelength, and reflectance. A conventional fundus camera is adapted to a spectrograph and an intensified charge coupled device (CCD) matrix detector system. The spectral resolution of this spectrometer is lower than 2 nm within a spectral range between 395 and 710 nm. The local resolution is lower than 23 microns along a line of 1.5 mm. From an imaging spectrum, the extinction spectrum of blood in vessels can be calculated. Also, in case of a noisy extinction spectrum of blood, its approximation by a model function results in calibration-free measurement of the oxygen saturation. Considering the radiation transport in single fundus layers, the local distribution of the concentration-thickness product of xanthophyll, melanin, and choroidal blood can be calculated.

MeSH terms

  • Animals
  • Diagnostic Imaging / instrumentation
  • Diagnostic Imaging / methods*
  • Eye / blood supply*
  • Fovea Centralis
  • Lutein / metabolism
  • Melanins / metabolism
  • Microcirculation
  • Ophthalmology*
  • Oxygen / metabolism
  • Retinal Vessels / metabolism
  • Spectrophotometry
  • Swine

Substances

  • Melanins
  • Oxygen
  • Lutein