Morphometry of diabetic conjunctival blood vessels

Photographs of the bulbar conjunctiva of 56 diabetic and 59 nondiabetic control patients were analyzed by newly developed morphometric techniques. When compared to controls diabetic patients showed: (1) decreased vascularity in the capillary bed but an increased vascularity of the venules with a volume shift in the distribution of blood into the venules; (2) an increased capillary pressure but comparable flow and, therefore, increased capillary resistance; (3) an increase in the range of background density suggesting either focal thickening of the interstitial tissue or variable amounts of fluid within the tissue; (4) a decrease in the percentage of the area occupied by microvessels; and (5) an increase in diffusion distance to all vessels.