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Updated: May 19, 2026
Retinal Vascular Reactivity as Assessed by Optical Coherence Tomography Angiography
Published on: March 26, 2020
Comparative analysis of the retinal microvasculature visualized with fluorescein angiography and the retinal function
Andre J Witkin1, Rayan A Alshareef, Sami S Rezeq
1The Retina Service, Wills Eye Institute and Thomas Jefferson University, Philadelphia, PA 19107, USA.
Purpose:
To assess the visualization of the retinal microvasculature with intravenous fluorescein angiography (IVFA) compared to the Retinal Function Imager (RFI).
Design:
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.
