Study of apoptosis in the rabbit cornea epithelium after photorefractive keratectomy

Objective To evaluate the level of apoptosis in the corneal epithelium after photorefractive keratectomy(PRK).Methods Six rabbits were anesthetized systemically with sodium pentobarbital.PRK was then performed and the central 5.6mm area of the cornea was ablated to a depth of 156μm(-8.0D).Rabbits were killed 1 month and 3 months after the performance respectivelly,and the cornea were prepared for frozen tissue sections.The apoptosis of the corneal epithelium was evaluated by TUNEL method.Results The normal corneal epithelium exhibited a limited level of apoptosis,primarily in the superficial epithelium.The entire epithelial layer was found to be apoptotic 1 month after PRK.The apoptosis of the corneal epithelium 3 months after PRK was the same as the normal corneal epithelium.Conclusion The apoptosis of corneal epithelium exist in wound healing process after PRK.The findings suggest that apoptosis plays an important role in the corneal wound healing process.