Figure 1.
Video fluorescein angiography in rat retina.
A–B. Representative bright-field image and its corresponding fluorescein image 10 seconds post fluorescein administration. C. Montage demonstrating the fluorescein transit through the retinal blood vessels for times between 6.2 and 20.9 seconds after the start of fluorescein infusion. Montage shows every 20th frame taken from Video S1. White bar in Panel A represents 500 µm.
Figure 2.
Video fluorescein dynamics in rat retinal vessels.
A. Representative intensity profile for an individual pixel before (grey trace) and after PCA (green trace). B. Representative normalized fluorescein intensity profile as a function of time in an artery (red), vein (blue) and capillary/choroid (green). Parameters used to analyze fluorescence profiles include the half-rise, half-fall and offset amplitude.
Figure 3.
Pixel-by-pixel analysis of retinal video fluorescein angiography.
(A). The half-rise (B) and half-fall (C) parameters of the same retina. Warmer colors indicate increasing delay in the parameter. Arrowheads indicate areas of early choroidal filling (red), delayed fluorescein clearance due to secondary venules (white) and delayed choroidal clearance (black). The offset amplitude (D) expressed relative to maximum fluorescence (%).
Figure 4.
Segmentation of pixel-by-pixel analysis by blood vessel type.
A–C. Development of the mask via manual vessel tracing: artery, capillary/choroid and vein respectively. D–F. Representative images of the half-rise of each pixel. G–I. Representative images of the half-fall of each pixel. J–K. Group average of the half-rise and fall respectively, across the four quadrants of the retina shows fluorescein filling in the order of arteries, capillaries and veins followed by their decay. Significant differences in rise (p = 0.01) and fall (p<0.001) were found between vessel types (two-way ANOVA). Data shown is mean ±SEM, n = 14.
Figure 5.
Half-rise and half-fall characteristics across two eccentricity zones.
Group averaged comparison of changes to half-rise and half-fall time in arteries (A–B), capillaries (C–D) and veins (E–F). Inset shows how the retina was divided into 4 sectors with two eccentricity zones forming the inner (light shade) and outer zones (dark shade). Unfilled markers represent the inner zone and filled markers show the outer zone. Data shown is mean ±SEM, n = 14.
Figure 6.
Video Fluorescein dynamics following laser injury.
A. Fluorescein angiogram leakage 60 seconds post dye delivery. B. Pixel-by-pixel analysis highlights areas of prolonged half-fall in laser-injured retina. C. Analysis of offset amplitude highlights the extent of elevated offset post-laser injury. D. Representative intensity profiles of two pixels within a laser-burned region highlighting the diversity in fluorescence dynamics. The red trace demonstrates continuous increase in fluorescence; green trace shows minimal fluorescence decay plotted against a representative intensity profile in the control cohort (blue trace). Data expressed in raw intensity with arbitrary units, colours of trace correlate to the relative offset of the pixel.
Figure 7.
Half-fall and offset characteristics following laser injury in rat retina.
Retinal probability maps identifying the areas of abnormal half-fall (1st and 3rd rows) and offset amplitude (2nd and 4th rows) in relation to the number of standard deviations from the mean of the whole image, n = 7 eyes. Panels A to G represent each of the 7 laser-injured retinas.