[Changes in Retinal Vascular Caliber after Intravitreal Aflibercept Treatment for Diabetic Macular Oedema]

Diabetic retinopathy is characterised by impaired retinal vascular autoregulation with signs of early retinal hyperperfusion and subsequent capillary drop out and peripheral ischemia. Initial retinal vascular dilation indicates disease progression and subsequent constriction signals a proliferative state. In this pilot study, we examined the effect of intravitreal aflibercept on retinal vessel diameter in patients with diabetic macular oedema.

Twelve eyes of nine treatment-naive patients with diabetic macular oedema were examined during the first three months of treatment with aflibercept. The calibers of retinal arteries and veins and the central retinal arterial and vein equivalent were registered over the course of treatment. The evolution of the diabetic macular oedema was also registered and correlated to the retinal vascular caliber.

During treatment, there was a significant reduction in the diameter of retinal arteries as well as in the central retinal arterial equivalent. The calibers of the retinal veins were also reduced, but not significantly. Macular oedema was significantly reduced, which however did not correlate with the vascular caliber changes.

This pilot study demonstrates for the first time a possible significant reduction in retinal arterial caliber under aflibercept treatment for diabetic macular oedema. Further studies are needed to verify whether this response to intravitreal anti-VEGF treatment also signifies an improvement in retinal vascular homeostasis.