Effects of pars plana vitrectomy on retrobulbar haemodynamics in diabetic retinopathy

Background: The purpose of the present study was to determine the effects of pars plana vitrectomy on retrobulbar haemodynamics in patients with proliferative diabetic retinopathy (PDR). Methods: Colour Doppler imaging was used for measurement of blood flow velocities and resistive index of the ophthalmic artery (OA), posterior ciliary arteries (PCA) and central retinal artery (CRA) in 14 eyes of 14 patients with PDR before pars plana vitrectomy and at the 1 and 6 months after operation. The patients were also treated by laser photocoagulation before or during surgery. Twenty age‐ and sex‐matched healthy subjects were used as control group. Results: Mean peak systolic velocity and the end diastolic velocity of the CRA in the patients with PDR were lower and the mean resistive index was higher than in those of the control group (P