Morphometric analysis of basal laminae in rats with long-term streptozotocin diabetes L. II. Retinal capillaries.

Twelve months after onset of streptozotocin-induced diabetes in rats, the basal lamina width of peripheral retinal capillaries, as measured with two different morphometric methods, is increased only in the basal lamina regions adjacent to perivascular glial cells. In the region between endothelial cells and pericytes no increase of thickness was observed. These facts support the suggestion of a predominantly glial (neuroectodermal) contribution to basal lamina thickening of retinal capillaries in diabetes mellitus. No correlation exists between the degree of basal lamina thickening at the different anatomic sites. Furthermore, no clear-cut correlation was found between basal lamina thickening and severity of the metabolic disease.