Review of paediatric retinal microvascular changes as a predictor of cardiovascular disease

Abstract

Recent studies have supported the hypothesis that exposure to established cardiovascular risk factors in early life predisposes to the development of adult cardiovascular disease. Retinal imaging is an emerging technique which facilitates non-invasive, accurate and reproducible assessment of the retinal microvasculature. The assessment may be in the form of static vascular calibre measurements and assessment of the vascular geometry or dynamic structural and functional assessments. Paediatric retinal microvascular changes are reported in response to elevated blood pressure, type 1 diabetes, increasing adiposity, diet, physical activity, systemic inflammation, metabolic peptides, family history and prenatal factors. The resultant microvascular changes have been linked to subclinical and overt cardiovascular, cerebrovascular and metabolic disease states in the adult population. Still missing however is longitudinal evidence showing the persistence of retinal microvascular alterations into adulthood. Future studies will enable retinal microvascular assessment to further evaluate the pathogenesis of disease states and response to intervention. The data obtained will also aid in expanding the clinical utility of retinal imaging as a cardiovascular risk prediction and monitoring tool and supplement existing recommendations to reduce cardiovascular morbidity and mortality.

Characteristics of the retinal microvasculature in association with cardiovascular risk markers in children with overweight, obesity and morbid obesity

“…In adults, narrower retinal arteriolar diameters and wider retinal venular diameters have been associated with increased cardiovascular risk 8 – 11 . Increasing evidence suggests that cardiovascular risk markers in early life are also associated with structural changes in the retinal microvasculature 12 , 13 . In population-wide cohort studies in children and adolescents, both retinal arteriolar and venular diameters have been associated with body mass index (BMI) 14 – 21 .…”

Review of the association between retinal microvascular characteristics and eye disease

“…Retinal geometric indices measure the departure of the retinal vessel arrangement from an ideal configuration (termed optimality deviance) . Geometric indices are thought to better represent the health of the microvascular bed than calibre indices; however, good data are lacking on their predictive capacity compared to calibre measurements and structural alterations, such as focal arteriolar narrowing . Characteristics of a vessel’s geometry that can be measured include tortuosity, bifurcation angle, length‐to‐diameter ratio and optimality deviance.…”

“…Characteristics of a vessel’s geometry that can be measured include tortuosity, bifurcation angle, length‐to‐diameter ratio and optimality deviance. Each of these characteristics provides some information regarding the health of the vascular network . The retinal vasculature of healthy controls branches in a similar and repeating pattern each time it divides, a trait termed ‘self‐similarity’.…”

“…Diabetic retinopathy remains the most common retinal vascular disease and its associations with retinal microvascular changes from large population‐based studies have been extensively reported. Multiple review articles summarizing the retinal microvascular associations in diabetes for both the adult and the paediatric population have been published . These reviews have typically addressed four key associations; first the microvascular maladaptations predicting disease in non‐diabetics, second the prevalent microvascular characteristics in those with diabetes, third the predictors of incident and progression of retinopathy and fourth the differences in the microvasculature in diabetics with retinopathy compared with those without retinopathy.…”

“…The assessment of vascular geometry is based on measurements of the departure of the branching pattern of the retinal vessels from an ideal arrangement in which retinal blood flow is optimized and endothelial shear stress is minimized. These measures, including vessel tortuosity, branching angle, optimality deviation, length‐to‐diameter ratio and lower fractal dimension, have shown association with both incident and prevalent diabetes and diabetic retinopathy . There are sparse data comparing the predictive capacity of these geometric indices with vascular diameter measurements .…”