Mj. Kim et al., Optimal concentration of human epidermal growth factor (hEGF) for epithelial healing in experimental corneal alkali wounds, CURR EYE R, 22(4), 2001, pp. 272-279
Purpose. By using both in vivo and in vitro (organ-cultured) systems, the o
ptimal concentrations of hEGF to enhance epithelial healing after alkali wo
unds were evaluated in the rabbit cornea.
Methods. Alkali-injured corneas (phi = 5.5 mm, 1N NaOH, 60 s) were treated
with 0.01, 0.1, 1.0, 10 and 100 ng/ ml hEGF for the in vitro study. The hea
ling of epithelium and endothelium was determined at 1, 2, 3, 4, and 6 days
after treatment. For the in vivo experiment, the eyes were treated with 2,
5, 10, and 50 mug/ml hEGF 3 times per day. The measurement of epithelial h
ealing rate, transmission electron microscopy and immunohistochemical obser
vation were performed after 7 days treatment.
Results. In in vitro tests, hEGF enhanced the epithelial healing rates, sho
wing a maximum enhancement at the concentration of 1.0 ng/ ml, and endothel
ial healing was increased at 100 ng/ ml. In in vivo studies, no significant
difference was observed in the rates of epithelial healing between control
and each hEGF-treated group. Among the tested concentrations, 5 mug/ml hEG
F induced the most active proliferation of basal cells and 50 mug/ml hEGF r
emarkably produced a vascular ingrowth to the central wound area. The thick
ness of re-surfaced epithelium was increased by hEGF in a concentration-dep
endent manner.
Conclusions. The results of the present study indicate that a low concentra
tion of hEGF may selectively enhance epithelial healing without affecting e
ndothelial healing. The optimal concentration of hEGF for the stimulation o
f epithelial healing appears to be 5 mug/ml in rabbit corneal alkali wounds
.