Wound healing following anterior keratectomy and lamellar keratoplasty in the pig.
OBJECTIVE
To examine corneal wound healing in an animal model of two types of mechanical lamellar keratectomy.


METHODS
One eye from each of 28 pigs was studied. Using a motorized keratome, corneas were subjected to an anterior lamellar keratectomy with removal of anterior stroma and epithelium, or to automated lamellar keratoplasty (ALK) with reapposition of a corneal flap. The exposed stromal surfaces were labeled intraoperatively with a fluorescent dye (DTAF) to assess deposition of stromal components during subsequent wound healing. Examination before surgery and enucleation included measurement of corneal curvature and intraocular pressure, and assessment of corneal haze. Eyes were prepared for histological examination, fluorescence microscopy, and for fibronectin immunohistochemistry.


RESULTS
Both keratectomy procedures produced flattening of corneas by up to 3.80 diopters, 28 days after surgery. Corneal haze was more pronounced in eyes from which epithelium was removed (anterior lamellar keratectomy group). The increased haze in this group was associated histologically with appearance of many reactive keratocytes and inflammatory cells, deposition of new stromal material, and more widespread appearance of fibronectin immunoreactivity. In the lamellar keratoplasty group, only the edges of the corneal wound showed significant reactivity, and included keratocyte activation and epithelial ingrowth.


CONCLUSIONS
The pig provides a useful model for studies of refractive surgical techniques using procedures and instruments designed for use in humans. Mechanized keratectomy procedures that minimize disruption of the epithelium and Bowman's layer produce a less reactive corneal wound than procedures in which an expanse of epithelium and anterior stroma are removed.
Sweatt
A J
AJ
Wake Forest University Eye Center, Winston-Salem, USA.
Ford
J G
JG
Davis
R M
RM
D000818:Animals; D003315:Cornea / Q000033:anatomy & histology / Q000502:physiology / Q000601:surgery*; D016039:Corneal Transplantation / Q000379:methods*; D053685:Laser Therapy; D013552:Swine; D014945:Wound Healing