[The specificity of the ultrastructural pattern of neoplastic vessels of the retina in diabetic retinopathy].

The electron microscopy of 14 samples of epiretinal membranes obtained in the course of transciliary vitrectomy performed in proliferative diabetic retinopathy (PDR) showed a majority of neovascularized vessels to be represented by those of the venular type or capillaries. It can be concluded on the basis of examination results that the structures of neovascularized vessels can be highly diverse in diabetic retinopathy, which depends on a variety of factors: 1) proliferation stage; 2) division of the microcirculation bed; and 3) end of the epiretinal membrane where a given vessel is located as to the growth epicenter. Finally, described are both neo-vessels with a virtually normal structure of the vascular wall and atrophying vessels. The signs of vascular reduction grow to be more pronounced at later stages.