Corneal wound healing in the rabbit eye: activity of a fibronectin-splitting product

The corneal wound-healing properties of fibronectin (FN) and a fibronectin hydrolysate (FNH) have been evaluated in comparison with commonly used drugs. Nonpenetrating bilateral surgical keratectomy was performed in male albino rabbits. The left eye was treated with the active product, whereas the right eye served as a control (vehicle). The healing area was measured by planimetry after fluorescein staining at 0, 24, 48, and 72 h after keratectomy. Histological and immunohistochemical analysis of the healing process was also performed. Results were as follows: (a) Nandrolone (p < 0.005) and asiaticoside (p < 0.001), both at 10 mg/ml, in eyedrops delayed the healing process. (b) An ointment containing vitamin A and amino acids also delayed the process but at the limit of statistical significance (p = 0.055). (c) FNH (20-80 mg prot/ml) significantly improved the quality and shortened the time of the healing process at 60 mg prot/ml and above. (d) Human FN (100-800 micrograms/ml) did not affect the healing process. Immunohistochemical analysis demonstrated that FNH accelerated the appearance of endogenous FN in the damaged cornea earlier than in the control eyes. It is concluded that FNH may be useful in the management of corneal wounds, whereas the effectiveness of FN is doubtful.