title: Pre-injection fluorescence in indocyanine green angiography.
abstract: OBJECTIVE
  To verify whether infrared pre-injection fluorescence can be observed in patients undergoing indocyanine green (ICG) angiography.
  
  
  METHODS
  Infrared fundus photographs were taken before dye injection for 450 consecutive patients undergoing ICG angiography for different chorioretinal disorders. The authors used a high-resolution videoangiography system with the standard ICG filters inserted (overlap, < 0.5%) and the highest flash intensity.
  
  
  RESULTS
  Pre-injection fluorescence was detected in 184 patients (40.8%). It was a strong fluorescence in 75 patients (40.7%) and a faint fluorescence in 109 (59.2%). When fluorescence was strong, it simulated vascular filling on the ICG angiogram. Pre-injection fluorescence resulted from the following lesions: (1) old grayish subretinal hemorrhages (35 patients); (2) lipofuscin-like deposits (65 patients); (3) pigmented choroidal neovascular membranes (72 patients); and (4) serous retinal detachments lasting from several months or years (12 patients). Highly reflecting white lesions were not fluorescent.
  
  
  CONCLUSIONS
  Pre-injection fluorescence of chorioretinal lesions is frequently detectable in patients with diseases requiring ICG examination. A pre-injection photograph may help to avoid misinterpretation of the angiograms. The authors' findings may be interpreted as pseudofluorescence or autofluorescence. Pigments contained in pathologic structures of the ocular fundus may be the source of autofluorescence emissions in the near-infrared range.
authors.affiliation: University Eye Clinic of Genoa, Italy.
authors.forename: F C
authors.initials: FC
authors.lastname: Piccolino
authors.forename: L
authors.initials: L
authors.lastname: Borgia
authors.forename: E
authors.initials: E
authors.lastname: Zinicola
authors.forename: M
authors.initials: M
authors.lastname: Iester
authors.forename: S
authors.initials: S
authors.lastname: Torrielli
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015862:Choroid Diseases / Q000473:pathology*; D005451:Fluorescein Angiography; D005453:Fluorescence; D005654:Fundus Oculi; D006801:Humans; D007208:Indocyanine Green; D007259:Infrared Rays; D007267:Injections; D008875:Middle Aged; D012164:Retinal Diseases / Q000473:pathology*; D014741:Video Recording
chemical_list: D007208:Indocyanine Green