Abstract
Aims/hypothesisOur aim was to determine whether a range of prespecified retinal vessel traits were associated with incident diabetic retinopathy in adults with type 2 diabetes.MethodsIn the prospective observational cohort Edinburgh Type 2 Diabetes Study of 1066 adults with type 2 diabetes, aged 60–75 years at recruitment, 718 were free from diabetic retinopathy at baseline. Baseline retinal traits including vessel widths, tortuosity (curvature) and fractal dimensions (network complexity), were quantified using fundus camera images and semiautomated software, and analysed using logistic regression for their association with incident diabetic retinopathy over 10 years.ResultsThe incidence of diabetic retinopathy was 11.4% (n = 82) over 10 years. After adjustment for a range of vascular and diabetes-related risk factors, both increased venular tortuosity (OR 1.51; 95% CI 1.15, 1.98; p = 0.003) and decreased fractal dimension (OR 0.75; 95% CI 0.58, 0.96; p = 0.025) were associated with incident retinopathy. There was no evidence of an association with arterial tortuosity, and associations between measurements of vessel widths and retinopathy lost statistical significance after adjustment for diabetes-related factors and vascular disease. Adding venular tortuosity to a model including established risk factors for diabetic retinopathy (HbA1c, BP and kidney function) improved the discriminative ability (C statistic increased from 0.624 to 0.640, p = 0.013), but no such benefit was found with fractal dimension.Conclusions/interpretationIncreased retinal venular tortuosity and decreased fractal dimension are associated with incident diabetic retinopathy, independent of classical risk factors. There is some evidence that venular tortuosity may be a useful biomarker to improve the predictive ability of models based on established retinopathy risk factors, and its inclusion in further risk prediction modelling is warranted.Graphical abstract
Highlights
The microvasculature of the retina offers a unique opportunity for research of the systemic vascular system as it is one of the only locations in vivo where it is possible to visualise the vasculature of the human body non-invasively [1]
Study design and participants The Edinburgh Type 2 Diabetes Study (ET2DS) is a longitudinal cohort of older men and women based in Lothian, Scotland, designed to investigate the role of risk factors for vascular complications of type 2 diabetes
Increased venular tortuosity and decreased fractal dimension were independently associated with incident diabetic retinopathy above and beyond other known risk factors
Summary
The microvasculature of the retina offers a unique opportunity for research of the systemic vascular system as it is one of the only locations in vivo where it is possible to visualise the vasculature of the human body non-invasively [1]. It is well known that providing early treatment for diabetic retinopathy can improve visual outcomes [3], such that screening programmes are commonplace in many countries. These programmes can only detect prevalent disease, so there is a need for more sensitive screening for prepathological stages of retinopathy as well as improved stratification to help clinicians understand which patients are more likely to progress to sightthreatening stages. Several cross-sectional studies have investigated associations between measurements of retinal vessel traits on fundus camera images and diabetic retinopathy in older adults, and these studies provided some evidence for an association between abnormally wider retinal venular calibre and diabetic retinopathy [7,8,9]. There is a need for prospective studies to evaluate if retinal vascular measurements could be used as biomarkers to predict subsequent development of diabetic retinopathy
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
