ASSESSMENT OF THE SKIN AND RETINAL MICROVASCULATURE WITH THE OPTICAL METHODS OF DIAGNOSTICS IN PATIENTS WITH DIABETES MELLITUS

Background: Abnormalities of microvasculature could be an early marker of diabetic complications. Therefore, its non-invasive assessment in diabetic patient seems highly relevant. Aim: To assess microcirculation in the skin and retina of patients with diabetes mellitus using optical diagnostic techniques: laser Doppler flowmetry (LDF) and Retinal Vessel Analyser (RVA). Materials and methods: Cutaneous microcirculation rhythms were analyzed in 18 patients with type 2 diabetes mellitus and 16 healthy volunteers in the MONIKI (Moscow, Russia). Microcirculation in the dorsal hand and foot skin was assessed by LDF for 2 minutes. The amplitude and frequencies of perfusion oscillations corresponding to the rhythms of various etiologies were computed by Waveletanalysis. Retinal vasomotions and their changes were studied in 33 type 1 diabetic patients compared to 33 healthy volunteers in the Aachen University of Applied Sciences (Germany). Original recordings made by the RVA were used for the analysis with a  Fourier transformation, cross-correlation and autocorrelation. Results: There was no significant difference in the hand skin microcirculation rhythms assessed by LDF between patients with diabetes mellitus and healthy volunteers, whereas in the lower extremities, statistically significant differences were found in the amplitude of high-frequency oscillations corresponding to the range of the heart rhythm. These results correlate well with the results of the optical assessment of retinal vasculature, where statistically significant differences in the amplitude of high frequency oscillations corresponding to the heart rate were found. In type 1 diabetic patients the periodicity of venous pulsation was higher than in the control healthy group. Conclusion: Both dynamic analysis of the pulsations and vasomotions of retinal vessels assessed by RVA and analysis of the rhythms of blood circulation in the skin of the lower extremities measured by LDF revealed a  statistically significant abnormalities of the microcirculatory dynamics in diabetic patients. The combination of these methods can be successfully applied for a  more comprehensive evaluation of the nature of microvascular abnormalities in diabetic patients and for comparison of the information obtained with clinical data.

pulsation, vasomotion, autoregulation, retina, skin microcirculation, non-invasive diagnostics, laser Doppler flowmetry, retinal vessel analyser