TY - JOUR
T1 - Retinal Fractal Dimension Is a Potential Biomarker for Systemic Health-Evidence From a Mixed-Age, Primary-Care Population
AU - Engelmann, Justin
AU - Kearney, Stephanie
AU - McTrusty, Alice
AU - McKinlay, Greta
AU - Bernabeu, Miguel O
AU - Strang, Niall
N1 - Supported by a grant from UK Research and Innovation (EP/S02431X/1 to JE) as part of the Centre of Doctoral Training in Biomedical AI at the School of Informatics, University of Edinburgh; Fondation Leducq Transatlantic Network of Excellence (17 CVD 03 to MOB); a grant from the Engineering and Physical Sciences Research Council (EP/X025705/1); British Heart Foundation and The Alan Turing Institute Cardiovascular Data Science Award (C-10180357); and Diabetes UK (20/0006221). MOB and NS acknowledge funding from Fight for Sight (5137/5138); SCONe projects funded by the Chief Scientist Office, Edinburgh & Lothians Health Foundation, Sight Scotland, and the Royal College of Surgeons of Edinburgh; RS Macdonald Charitable Trust.
PY - 2024/4/12
Y1 - 2024/4/12
N2 - 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.
AB - 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.
KW - fractal dimension
KW - oculomics
KW - retinal image analysis
U2 - 10.1167/tvst.13.4.19
DO - 10.1167/tvst.13.4.19
M3 - Article
C2 - 38607632
SN - 2164-2591
VL - 13
JO - Translational Vision Science & Technology
JF - Translational Vision Science & Technology
IS - 4
M1 - 19
ER -