Abstract
Purpose :
The geometry of the retinal vascular network may reflect the overall health of the vascular tree. The aim of this study was to analyse the associations between retinal vessel geometry and the one-year incidence and progression of diabetic retinopathy (DR) in a Chinese population.
Methods :
This was a prospective cohort study of adult subjects with diabetes mellitus. Retinal vascular geometry (retinal vessel fractal dimensions, tortuosity, branching coefficients and branching angles) was quantified from retinal fundus photographs using a semi-automated computer-assisted program. DR was graded from retinal photographs at baseline and at 1 year. Incident DR and proliferative DR (DR), and 2 step change in DR were analysed.
Results :
In total, 249 subjects were included. The mean age of the subjects was 59.9±8.9 years, the majority were male (74%) and the mean HbA1c level and mean duration of diabetes were 7.7±1.4% and 14.3±10.6 years respectively. The incidence of DR at 1 year was 19 out of 90 subjects (21.1%) and the incidence of PDR was 8 out of 235 subjects (3.4%). The number of subjects with 2 step or greater progression of DR at 1 year was 38 of 235 (16.2%), while 51 of 143 subjects (35.7%) had 2 step or greater regression.
In multivariate analyses adjusting for age, duration of diabetes, gender, smoking status, hba1c, hypertension and hyperlipidaemia, subjects with the highest venular fractal dimensions were more likely to have incident DR. [Odds Ratio (OR) 0.38, (95% confidence interval, CI, 0.15 – 0.96), p=0.03, per standard deviation (SD) decrease]. Lower venular branching coefficients were associated with incident PDR.[OR 70.64, (95% CI, 4.77 – 1046.6), p=0.02, per SD decrease]. Lower venular tortuosity was associated with a lower likelihood of DR progression [OR 0.76, (95% CI, 0.59 – 0.97), p=0.005, per SD decrease]. Lower arteriolar tortuosity was associated with a greater likelihood of DR regression[OR 1.95, (95% CI 1.07 – 3.56), p=0.04, per SD decrease].
Conclusions :
Novel measures of retinal vascular geometry are associated with the incidence and progression of DR at 1 year. These geometric measures may represent early dysfunction in the retinal microvasculature.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.