Doppler ultrasound in type I diabetes: preliminary results

Objective: To study the differences of blood flow in type I diabetes patients using a color Doppler ultrasound.

Methods: We measured the systolic peak velocity (Vmax), diastolic velocity (Vmin) as well as the resistance index in the central retinal artery (CRA) and in the ophthalmic artery (OA) using a color Doppler ultrasound in 40 diabetic patients. We classified the patients according to the duration of diabetes, which ranged from 1 to 28 years. and whether retinopathy was present. We compared the results against those obtained in the 40 control subjects without vascular pathology.

Results: When the results of the two groups were compared, we found that no decrease was observed in the CRA flow rate in diabetics without retinopathy, however there was a significant decrease in flow velocity in patients with initial (p<0.05), moderate (p<0.001) or proliferative retinopathy (p<0.05). The ophthalmic artery presents an increase in the vascular resistance in diabetics with proliferative retinopathy. As the time of diabetes increases, there is a decrease in the blood flow in CRA and an increase in resistance in the OA.

Conclusions: The Doppler ultrasound is a non-invasive technique which allows us to perform a hemodynamic study of the orbital vessels. It is essential to understand the correlation between blood flow velocity and the severity of retinopathy in diabetes patients as it manifests the relationship between the velocity of the blood flow with the severity of the retinopathy and that there is a direct relationship with the evolution of the diabetes and the flood flow velocity.