[Transcapillary diffusion of Na-fluorescein in skin areas of the dorsum of the foot in juvenile diabetics]

Abstract

Fluorescence videomicroscopy after intravenous injection of Na-fluorescein serves to quantitate dye diffusion out of single capillaries or capillary groups in an almost atraumatic manner [2, 4, 6, 8, 9]. In 14 young patients with a mean disease duration of 10 years and in 16 healthy controls, fluorescent light intensity was measured continuously during one hour at the dorsum of the foot by a videodensitometer covering an average of 68 capillaries. 1 second and 5 minutes after first appearance of the dye in the foot skin, the amount of the tracer detected in the area of measurement was significantly increased in the diabetics (p less than 0.05-0.001). At 1 minute, for example, mean fluorescent light intensity reached 47.2 +/- 18.1% of the maximal individual intensity and in the normals only 29.3 +/- 10.8% (p less than 0.01). In the patients the capillaroscopic image was characterized by early blurring, whereas the pericapillary halo of the controls contained more dye than the more remote interstitial space and remained well delineated for a much longer time. The new technique offers the possibility of studying transcapillary diffusion as an expression of microangiopathy in different groups of diabetic patients, and of following the effect of therapeutic regimens.