Aim. To evaluate the influence of the single application of a topical venoactive agent on intradermal veins and the surrounding tissues in the patients presenting with primary chronic class C1—C3 venous disease of the lower extremities. Material and methods. This study included 114  patients presenting with primary chronic class C1—C3 venous disease of the lower extremities who were treated by means of the single application of a topical venoactive preparation containing the extract of the red grape leaves (with querticine derivatives as  the active ingredients) on the skin of the lower extremities. This treatment was followed by optical coherent tomography with the use of a computerized optical coherent visualizing-tomograph. Results. Prior to the treatment by gel  application, all the patients were characterized by  moderately reduced brightness and contrast of the skin layers as well as flattening and blurring of the boundary of the dermo-epidermal junction in the case of class C3 disease. The dermal layer contained polymorphous structures identified as venules that were especially well apparent in the patients with class C1 and C2 diseases. In the patients presenting with C3 disease, vessel visualization was significantly worsened in proportion to the severity of tissue oedema. Visualization of the vascular component of the skin was altogether impossible in 17 patients with the most pronounced oedema. Two patients had venules of the regular oval shape suggesting manifest vascular hypertension. It was shown that one hour after the application of the topical agent, the concentration of the signal scattering centres and  contrast of images of  all  optical layers tended to increase which suggested a reduction of oedema. Moreover, the signs of the improvement of  venous outflow became apparent at the level of the skin microcirculatory system along with the reduction of venous pressure and the better protection of the skin from the development of trophic lesions. Conclusion. The application of a topical venoactive agent on the skin results in a decrease of tissue oedema and signs of local vascular hypertension which suggests that the preparation containing the extract of the red grape leaves exerts not only «local irritating» action but also possesses direct anti-oedematous dermatoprotective activity.