[Hemorheologic factors in hypertensive and diabetic retinopathy]

Hemorheological factors play an important role in the pathogenesis of different cardiovascular diseases. In the present study the fundus picture and hemorheological parameters (plasma and whole blood viscosity *WBV* by capillary viscosimetry; fibrinogen level; red blood cell aggregation by Myrenne and LORCA aggregometers) of 33 hypertensive patients (23 females, 10 males; mean age: 55 years) and 30 diabetic patients (14 females, 16 males; mean age: 57 years) and healthy controls were examined. The fundus pictures showed different forms of retinopathy in both groups. All the measured hemorheological parameters of the examined patients were in the pathological range and were significantly higher than in healthy controls. In the group of hypertensive patients hematocrit (p < 0.05), plasma fibrinogen (p < 0.01), plasma viscosity (p < 0.01) and whole blood viscosity (p < 0.01) showed a significant increase. The hemorrheological factors showed a parallel deterioration with the severity of hypertension (measured BP values) and of fundus picture, namely their values were significantly (p < 0.01) higher in patients with stage III fundus picture (WBV at 90 1/s: 6.02 mPas), than stage I hypertension (WBV at 90 1/s: 4.51 mPas). In the diabetic group hematocrit (p < 0.01), plasma fibrinogen (p < 0.001), plasma viscosity (p < 0.01), "WBV" (p < 0.001), red blood cell aggregation (p < 0.05) showed a significant increase comparing to healthy controls. These results show that there is a correlation between hemorrheological parameters and fundus picture in hypertensive and diabetic patients, and this suggests that hemorrheological factors may play a role in the development of hypertensive and diabetic retinopathy.