The eyes as a window to the heart: looking beyond the horizon

Abstract

Provenance and peer review Commissioned; internally peer reviewed.

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

“…Retinal color fundus imaging rapidly and non-invasively captures a detailed picture of the retinal vasculature while being widely available and low cost. Thus, retinal image–derived traits are being investigated as biomarkers for systemic health, a field also known as “oculomics.” 1 – 3 Fractal dimension (FD), a retinal trait relating to the complexity of the retinal vasculature, has emerged as a particularly promising candidate that is associated with cardiovascular 4 , 5 and neurovascular 6 , 7 disease. FD is calculated from vessel segmentations and captures how complex the branching structure of the blood vessels is.…”

Machine learning classification of retinal imaging of neuropsychiatric and healthy cases in a subset of the UK Biobank cohort

“…For example, microvascular changes in the retina correlate with structural and functional abnormalities in an individual's microcirculatory system, and detectable retinal microvascular changes are associated with cardiovascular events (Cheung et al, 2019). Retinal microvasculature offers a "window" into the functioning of one's cardiovascular system and "may reflect subclinical pathological changes prior to the development of cardiovascular disease" (Cheung et al, 2019, p. 308;Mordi & Trucco, 2022). Furthermore, a growing body of OCT imaging has connected pathologies of brain tissue with anomalies of retinal neuronal layers, indicating that neurological illness can manifest in the retina (Zafar et al, 2019).…”

“…Some of the specific features of retinal vasculature that can be assessed using CF imaging are: the curvature of the retinal blood vessels (vessel tortuosity); the diameter of the retinal blood vessels (vessel caliber); fluid leakage from the retinal blood vessels (vascular occlusion); and the formation of new blood vessels in the retina (neovascularization; De Boever et al, 2014;Panwar et al, 2016)). Variations in the measurement of these features are associated with systemic illnesses such as hypertension, diabetes, ADRDs, and cerebrovascular events (Cheung et al, 2019;De Boever et al, 2014;Mordi & Trucco, 2022;Tapp et al, 2019).…”

“…Furthermore, ICD-10 diagnoses of systemic nervous and circulatory illnesses were also excluded. The retina is described as a window into the brain (London et al, 2013) and the heart (Mordi & Trucco, 2022) as is composed of both microvascular and neuronal systems. Similar to diseases of the eye and retina, significant nervous and circulatory systemic illness can affect the retina substantially, weakening the signal of pathologies of neuropsychiatric disorders.…”