INTRODUCTION: Optical coherence tomography angiography is a non-invasive imaging technique
that is able to visualize the different retinal vascular layers using motion contrast
to detect blood flow without intravenous dye injection. This method might help to
assess microangiopathy in diabetic retinopathy during screening and follow-up. AIM:
To quantify retinal microvasculature alterations in both eyes of diabetic patients
in relation to systemic risk factors using optical coherence tomography angiography.
METHOD: Both eyes of 36 diabetic patients and 45 individuals without diabetes were
examined. Duration of diabetes, insulin therapy, blood pressure, HbA1c, dyslipidemia,
axial length and the presence of diabetic retinopathy were recorded. Retinal vessel
density was measured by optical coherence tomography angiography. The effect of risk
factors on vessel density and between-eye asymmetry was assessed using multivariable
regression analysis. RESULTS: Vessel density was significantly lower and between-eye
difference was significantly higher in diabetic patients compared to controls (p<0.05).
Both vessel density and between-eye asymmetry significantly correlated with diabetes
duration (p<0.05) after controlling for the effect of risk factors. The between-eye
asymmetry in vessel density was significantly higher in patients without clinically
detectable diabetic retinopathy compared to control subjects (p<0.001). CONCLUSIONS:
There is a decrease in retinal vessel density and an increase in between-eye asymmetry
in patients with diabetes compared to healthy subjects. By using optical coherence
tomography angiography, the detection of these microvascular alterations is possible
before clinically detectable diabetic retinopathy and might serve as a useful tool
in both screening and timing of treatment. Orv Hetil. 2018; 159(8): 320-326.