Retinal Fractal Dimension Is a Potential Biomarker for Systemic Health-Evidence From a Mixed-Age, Primary-Care Population

Justin Engelmann*, Stephanie Kearney, Alice McTrusty, Greta McKinlay, Miguel O Bernabeu, Niall Strang

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

PURPOSE: To investigate whether fractal dimension (FD), a retinal trait relating to vascular complexity and a potential "oculomics" biomarker for systemic disease, is applicable to a mixed-age, primary-care population.

METHODS: We used cross-sectional data (96 individuals; 183 eyes; ages 18-81 years) from a university-based optometry clinic in Glasgow, Scotland, to study the association between FD and systemic health. We computed FD from color fundus images using Deep Approximation of Retinal Traits (DART), an artificial intelligence-based method designed to be more robust to poor image quality.

RESULTS: Despite DART being designed to be more robust, a significant association (P < 0.001) between image quality and FD remained. Consistent with previous literature, age was associated with lower FD (P < 0.001 univariate and when adjusting for image quality). However, FD variance was higher in older patients, and some patients over 60 had FD comparable to those of patients in their 20s. Prevalent systemic conditions were significantly (P = 0.037) associated with lower FD when adjusting for image quality and age.

CONCLUSIONS: Our work suggests that FD as a biomarker for systemic health extends to mixed-age, primary-care populations. FD decreases with age but might not substantially decrease in everyone. This should be further investigated using longitudinal data. Finally, image quality was associated with FD, but it is unclear whether this finding is measurement error caused by image quality or confounded by age and health. Future work should investigate this to clarify whether adjusting for image quality is appropriate.

TRANSLATIONAL RELEVANCE: FD could potentially be used in regular screening settings, but questions around image quality remain.

Original languageEnglish
Article number19
Number of pages7
JournalTranslational Vision Science & Technology
Issue number4
Publication statusPublished - 12 Apr 2024

Keywords / Materials (for Non-textual outputs)

  • fractal dimension
  • oculomics
  • retinal image analysis


Dive into the research topics of 'Retinal Fractal Dimension Is a Potential Biomarker for Systemic Health-Evidence From a Mixed-Age, Primary-Care Population'. Together they form a unique fingerprint.

Cite this