Histochemical demonstration of adrenergic nerves in the stroma of human cornea

Both fetal and adult human corneas were subjected to a variety of histochemical techniques for the demonstration of catecholamines. The techniques included both sodium-potassium-glyoxylic acid-induced fluorescence (SPG) and formaldehyde-induced fluorescence after freeze-drying (FIF) procedure. In fetal corneas the presence of adrenergic nerve fibers could be demonstrated by both SPG and FIF techniques. In contrast, in adult human corneas the adrenergic nerves could be identified only with the SPG technique, whereas with FIF the identification of specific catecholamine fluoresence was not possible due to extensive collagen autofluorescence.