title: Comparative analysis of the retinal microvasculature visualized with fluorescein angiography and the retinal function imager.
abstract: OBJECTIVE
  To assess the visualization of the retinal microvasculature with intravenous fluorescein angiography (IVFA) compared to the Retinal Function Imager (RFI).
  
  
  METHODS
  Multicenter, retrospective, observational case series.
  
  
  METHODS
  Seven normal eyes and 26 eyes with various ocular diseases were imaged with both IVFA and the RFI. The ability to assess vessel loops, vertical collateral vessels, the size of the foveal avascular zone (FAZ), and degree of vessel branching were compared between IVFA and RFI images.
  
  
  RESULTS
  The RFI visualized a greater number of vessel loops (1.3 vs 0.4 per eye) and vertical collateral vessels (4.42 vs 0.97 per eye) than IVFA. On average, higher order of vessel branching was seen with the RFI compared to IVFA (5.2 vs 4.6). The foveal avascular zone (FAZ) was more clearly delineated using the RFI and was significantly smaller when measured on RFI (0.35 vs 0.75 mm(2)).
  
  
  CONCLUSIONS
  RFI, a noninvasive retinal imaging instrument, revealed vessel loops, vertical collateral vessels, the area of the FAZ, and order of vessel branching in greater detail than IVFA. This instrument may be helpful in understanding dynamic retinal vascular changes in a number of common ocular diseases, as well as in normal eyes.
authors.affiliation: The Retina Service, Wills Eye Institute and Thomas Jefferson University, Philadelphia, PA 19107, USA.
authors.forename: Andre J
authors.initials: AJ
authors.lastname: Witkin
authors.forename: Rayan A
authors.initials: RA
authors.lastname: Alshareef
authors.forename: Sami S
authors.initials: SS
authors.lastname: Rezeq
authors.forename: Kapil M
authors.initials: KM
authors.lastname: Sampat
authors.forename: Jay
authors.initials: J
authors.lastname: Chhablani
authors.forename: Dirk-Uwe G
authors.initials: DU
authors.lastname: Bartsch
authors.forename: William R
authors.initials: WR
authors.lastname: Freeman
authors.forename: Julia A
authors.initials: JA
authors.lastname: Haller
authors.forename: Sunir J
authors.initials: SJ
authors.lastname: Garg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004912:Erythrocytes / Q000502:physiology; D005260:Female; D005451:Fluorescein Angiography / Q000379:methods*; D006801:Humans; D008297:Male; D055806:Microvessels / Q000473:pathology; D008875:Middle Aged; D061848:Optical Imaging / Q000379:methods*; D012164:Retinal Diseases / Q000175:diagnosis*; D012171:Retinal Vessels / Q000473:pathology*; D012189:Retrospective Studies; D055815:Young Adult