Does fractal properties of retinal vasculature vary with cardiac cycle?

In this work the significance in variation of region based fractal dimension of retinal images due to microvascular pulsatile changes has been investigated. A set of ECG-synchronized retinal images were taken at nine distinct cardiac points and the Higuchi and Box-counting fractal dimensions were calculated; after being registered and corrected for some disturbing artifacts (e.g, non-uniform illuminations). The result showed a statistical significant difference between the mean Higuchi fractal dimensions of 1^st and 4^th cardiac points measured in zone B (p=0.048, α=0.05). No statistical significance was found for other fractal measures (all p-values >0.05).