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Observational Study
. 2023 Oct;261(10):2787-2794.
doi: 10.1007/s00417-023-06117-x. Epub 2023 May 18.

Fractal analysis of the macular region in healthy eyes using swept-source optical coherence tomography angiography

Kowsigan Magesan #  1   2 , Ramya Gnanaraj #  2   3 , Jasaman Tojjar  3   4 , T Amose  1   2 , Ahmed Roshdy Alagorie  5 , Maanasi Mahalingam  1   2 , Parveen Sen  2 , Aditya Verma  2   3   6 , SriniVas R Sadda  7   8
Affiliations
Observational Study

Fractal analysis of the macular region in healthy eyes using swept-source optical coherence tomography angiography

Kowsigan Magesan et al. Graefes Arch Clin Exp Ophthalmol. 2023 Oct.

Abstract

Purpose: This cross-sectional observational study evaluated the relationship between retinal vascular fractal dimension (FD) and age, as well as other vascular parameters in healthy eyes using swept-source optical coherence tomography angiography (SS-OCTA).

Methods: The study cohort consisted of 222 eyes of 116 healthy participants with no ocular or systemic disease. SS-OCTA images were captured and analyzed using the Plex Elite 9000 and software tools available in the advanced retinal imaging (ARI) network hub. The retinal vascular layers were defined by the instrument's automatic retinal layer segmentation. The fractal analysis was performed on the superficial capillary plexus (SCP), deep capillary plexus (DCP), and the whole retina. Grayscale OCTA images were standardized and binarized using ImageJ and fractal box-counting analyses were performed using Fractalyse software. Pearson's correlation was used to analyze the correlation between FD and retinal vascular parameters.

Results: The results showed that FD values were significantly higher in the 6 mm ring and the whole 6 × 6 scan region when compared to the 1 mm ETDRS central subfield. The correlation between age and FD was weak with a significant positive correlation between age and FD of the SCP in the 6 mm ring and between age and FD of the DCP in the 1 mm ring. Overall, differences in FD values in these healthy eyes were extremely small regardless of age or macular location.

Conclusion: FD values in normal eyes show little variation with age and are relatively stable across the macula. This suggests that FD values may not need adjustment for age or location when evaluated in the context of retinal disease.

Keywords: Deep Capillary Plexus; Fractal Dimension; Perfusion density; Superficial Capillary Plexus; Swept-source optical coherence tomography angiography; Vessel length density.

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References

    1. Mandelbrot BB (1983) The fractal geometry of nature. Macmillan. W. H. Freeman & Co, New York
    1. Mandelbrot B (1967) How long is the coast of Britain? Statistical self-similarity and fractional dimension. Science 5:636–638. https://doi.org/10.1126/science.156.3775.636 - DOI
    1. Losa GA (2009) The fractal geometry of life. Riv Biol 102:29–59 - PubMed
    1. Mandelbrot BB (1983) The fractal geometry of nature. WH Freeman, New York, pp 151–165
    1. Reichenbach A, Siegel A, Senitz D et al (1992) A comparative fractal analysis of various mammalian astroglial cell types. Neuroimage 1:69–77. https://doi.org/10.1016/1053-8119(92)90008-b - DOI - PubMed

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