Effect of topical administration of epidermal growth factor on healing of corneal epithelial defects in horses.
OBJECTIVE-To characterize healing of corneal epithelial defects in horses and to evaluate the ability of epidermal growth factor (EGF) to modulate rate of corneal epithelial healing in horses.


METHODS
20 eyes in 12 adult horses.


METHODS
Corneal epithelial wounds were created by mechanically debriding the limbus. Corneal healing was recorded for 3 treatment groups: 50 microg of EGF/ml (n = 5 eyes), 5 microg of EGF/ml (7), and PBS solution (8). Corneal healing was recorded once daily after instillation of fluorescein stain by use of photography and calculating the area of the wound, using imaging software.


RESULTS
After corneal debridement, re-epithelialization was rapid and progressed in a linear fashion for the first 5 to 7 days after surgery in all groups. After that period, rates of healing decreased. A profound increase in the degree of inflammation, neovascularization, melanosis, and scarring was observed in eyes treated with the high dose of EGF (50 microg/ml), but there was not a statistical difference in mean healing time or in mean decrease in radius during the linear phase between the control and either EGF treatment groups. However, for all 8 horses in which both eyes were debrided, the first eye healed significantly faster than the second eye, regardless of treatment.


CONCLUSIONS
Beneficial effects of topical administration of a high dose of EGF for acceleration of healing of corneal defects in eyes of horses are outweighed by the intensity of the associated inflammatory response.
Burling
K
K
Animal Eye Specialists of San Jose, CA 95123, USA.
Seguin
M A
MA
Marsh
P
P
Brinkman
K
K
Madigan
J
J
Thurmond
M
M
Moon-Massat
P
P
Mannis
M
M
Murphy
C J
CJ
D000287:Administration, Topical; D000818:Animals; D003316:Corneal Diseases / Q000188:drug therapy / Q000662:veterinary*; D004815:Epidermal Growth Factor / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D004847:Epithelial Cells / Q000187:drug effects; D019573:Epithelium, Corneal / Q000293:injuries*; D005260:Female; D006734:Horse Diseases / Q000188:drug therapy*; D006736:Horses; D006801:Humans; D007249:Inflammation / Q000139:chemically induced; D008297:Male; D014945:Wound Healing / Q000187:drug effects*
D004815:Epidermal Growth Factor