METHOD FOR DETERMINING THE RISK FACTOR FOR THE PRESENCE OF DIABETIC RETINOPATHY IN PATIENTS WITH DIABETES MELLITUS Russian patent published in 2023 - IPC A61B5/205 A61B8/06 G01N33/49 A61B3/10 

FIELD: medicine.

SUBSTANCE: method for determining the risk factor for the presence of diabetic retinopathy in patients with diabetes mellitus. When executing the method, the level of skin microcirculation of the blood of the subject in a sitting position is assessed using the method of laser Doppler flowmetry using a thermal functional test on hand. Mathematical calculation of indicators for assessing microcirculation is carried out on the basis of the data obtained. In this case, before the measurement, the subject must adapt within 10 minutes in a relaxed sitting position to the conditions of the premises. Then the subject's hands are placed on a horizontal surface with palms down so that the forearms are at the level of the heart. A sensor for measuring skin microcirculation with a heating element is fixed 4 cm proximal to the wrist joint along the midline on the back surface of the forearm of one of the hands. Within 60 seconds, the base level of microcirculation is recorded at the temperature of the heating element in the temperature range of 32-32.4°C. Then turn on the heating of the element at a speed of 2°C per second up to 41.8-42.2°C and maintain this temperature until the end of the test. The study is stopped 180 seconds after the heating is turned on. Based on the data obtained, the slope of the linear regression function of the microcirculatory curve is calculated for two minutes of heating using the skin microcirculation index multiplied by 10:

,

where “Slope-120s” is the slope of the linear regression function; t is a specific point in time during the study, in seconds; I is the value of the microcirculation index at a particular point in time; is arithmetic mean value of time for the estimated period; is the arithmetic mean value of the microcirculation index for the estimated period; n61, n180 is the numerical values reflecting the number of measurements made on the 61st and 180th seconds of registration, respectively, which are calculated by the formula nt=t*v, where t is the time from the start of the study in seconds, and v is the number of measurements per second. If the value of the “Slope-120s” parameter is 0.91 PU/s or less, then a high risk of diabetic retinopathy in patients with diabetes mellitus is determined.

EFFECT: increased accuracy of determining the risk factor for the presence of diabetic retinopathy in patients with diabetes mellitus in order to conduct timely treatment.

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