A Study on the Possibility of Reducing Corneal Haze with Topical Application of Human Amniotic Fluid in the Wounds Induced by Excimer Laser Keratectomy in Rabbits

ABSTRACT

Scarless wound healing with minimal inflammation obscured in the fetal skin rpay be due to the fact that amniotic fluid contains factors that may modulate the wound healing process. To examine this possibility, We examined the effect of topical application of human amniotic fluid on the healing of rabbit corneal wounds induced by excimer laser stromal ablation. The right eye received undiluted human amniotic fluid(AF) drops(13th week gestational age) and the left eye received the BSS as a control five times a day for one month. Epithelial healing completed within three days. The wound healing rate was not significant in the early phase but was significant in the late phase(p<0.05). Keratometric regression was significantly less in human amniotic fluid treated(AF group) eyes than BSS treated(control group) eyes. Corneal opacity was significantly less in AF group than control group at one and three months after laser ablation using Scheimpflug camera photography and MacDonald-Schadock class ification(p<0.05). Morphological examination revealed convoluted basement membrane, discontinued hemidesmosome and increased number of activated keratocytes in BSS-treated eyes. These results indicate that corneal scarring(haze) can be reduced by topical application of human amniotic fluid. We speculate that amniotic fluid may contain factors that can facilitate the restoration of fetal environment for wound healing by inhibiting fibroblast activation, thus preventing scar formation.