[Changes in the vascular wall in the conjunctiva of patients with diabetes mellitus].

Venous capillary wall in type II diabetic patients' conjunctiva was examined. The study was performed on conjunctiva fragments removed from diabetic patients during the operation of senile cataract. The fragments were fixed in Lillie's solution then studied by using optical microscopy with usual but histochemical stainings, too. Conjunctiva fragments removed from patients of the same age, being operated by senile cataract and one conjunctiva from ten years old patient were examined by using the same techniques as they could be compared. Computer determinations of the external and internal diameter of the same capillary in all three groups were performed. Venous capillary wall thickening by type IV collagen hyperproduction in all the aged patients was noted. This kind of thickening is more revealed in aged diabetic person. Type I-III collagen presence in the capillary wall of the diabetic patients was noted, too. The average value of the differential between the external and internal diameter was increased in the diabetic patients with diabetic retinopathy. Venous capillary wall thickening in the diabetic patients is due to the basal membrana both by means of the type IV collagen hyperproduction and presence of the I-III collagen, too.