title: Relative contributions of the neurosensory retina and retinal pigment epithelium to macular hypofluorescence.
abstract: OBJECTIVE
  To determine quantitatively the relative contributions of the neurosensory retina (NR) and retinal pigment epithelium (RPE) to the macular hypofluorescence observed during routine fundus fluorescein angiography.
  
  
  METHODS
  Macular and peripheral buttons of neurosensory retina and retinal pigment epithelium were obtained from 10 postmortem human eyes. A well was created to simulate a fluorescein-filled choroid. The fluorescence of each tissue and combinations of tissue atop the well was determined using a fluorescence microscope. The percent reduction in the fluorescence of each, relative to the baseline fluorescence of the well alone, was calculated.
  
  
  RESULTS
  Macular RPE demonstrated substantially lower fluorescence than peripheral RPE in all subjects. Macular NR demonstrated lower fluorescence than peripheral NR in all but one subject. The addition of macular NR to macular RPE caused significantly less fluorescence in all cases. Macular RPE caused a much greater percent reduction in fluorescence than macular NR in all subjects.
  
  
  CONCLUSIONS
  Hypofluorescence of the macula relative to the peripheral retina is a well-known feature of fluorescein angiography. This phenomenon is predominantly owing to the RPE and minimally to the NR, which cause 90.6 and 13.6 mean percent reductions in fluorescence, respectively.
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin Medical School, Madison 53792-3220, USA.
authors.forename: M M
authors.initials: MM
authors.lastname: Boyer
authors.forename: G L
authors.initials: GL
authors.lastname: Poulsen
authors.forename: T M
authors.initials: TM
authors.lastname: Nork
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D002829:Choroid / Q000098:blood supply; D005260:Female; D005451:Fluorescein Angiography; D005453:Fluorescence; D006801:Humans; D008266:Macula Lutea / Q000098:blood supply*; D008297:Male; D008856:Microscopy, Fluorescence; D008875:Middle Aged; D010857:Pigment Epithelium of Eye / Q000502:physiology*; D012171:Retinal Vessels / Q000502:physiology*