Spectral profiling of autofluorescence associated with lipofuscin, Bruch's Membrane, and sub-RPE deposits in normal and AMD eyes

Invest Ophthalmol Vis Sci. 2002 Jul;43(7):2435-41.

Abstract

Purpose: To compare the autofluorescence spectra of retinal pigment epithelium (RPE)-associated lipofuscin, Bruch's membrane, and sub-RPE deposits (drusen and basal laminar-linear deposits) in eyes of donors with age-related macular degeneration (AMD) against eyes of age-matched control donors.

Methods: Cryosections were cut from the maculae of unfixed human donor eyes with AMD or from age-matched control eyes. Tissues were excited at wavelengths of 364, 488, 568, and 633 nm. Emission spectra were collected with a confocal microscope equipped with a spectrophotometric detector at 10-nm wavelength intervals between 400 and 800 nm.

Results: RPE lipofuscin had strong autofluorescent emissions that were excited at all wavelengths. Bruch's membrane exhibited strong autofluorescence with an emission peak of 485 +/- 5 nm when excited with 364-nm light. At 488-, 568-, and 633-nm excitations, Bruch's membrane and sub-RPE deposits in normal eyes exhibited minimal autofluorescence. In AMD eyes, however, both the 364- and 488-nm excitation wavelengths stimulated substantial blue-green emissions from sub-RPE deposits and Bruch's membrane, with average pixel intensities substantially exceeding that elicited in the yellow-orange range by RPE lipofuscin.

Conclusions: These data suggest that an increase in blue-green autofluorescence of Bruch's membrane relative to the yellow-orange autofluorescence of RPE-associated lipofuscin is associated with AMD. Knowledge of these spectra will be useful in evaluating animal models of macular degenerative disease and in diagnosis of AMD, and will provide a novel signature for further analysis of the molecular entities emitting these fluorescent signatures.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Bruch Membrane / metabolism*
  • Bruch Membrane / pathology
  • Female
  • Humans
  • Lipofuscin / metabolism*
  • Macular Degeneration / metabolism*
  • Macular Degeneration / pathology
  • Male
  • Microscopy, Confocal
  • Pigment Epithelium of Eye / metabolism*
  • Pigment Epithelium of Eye / pathology
  • Retinal Pigments / metabolism
  • Spectrometry, Fluorescence

Substances

  • Lipofuscin
  • Retinal Pigments