Changes in descemet membrane and endothelium after corneal epithelial abrasion alone and with photorefractive keratectomy in rabbits.

OBJECTIVES

To investigate the effects of epithelial abrasion on the corneal endothelium and Descemet membrane in rabbits and to compare the changes with those after excimer laser photoablation of the cornea.

METHODS

Central epithelial abrasions, 6 mm in diameter, were created by mechanical removal of the cells, and the specimens were examined from 24 hours up to 30 days by transmission electron microscopy. Corneas that were photoablated by an excimer laser and nontreated normal corneas were investigated as controls.

RESULTS

Corneas denuded of epithelium showed massive enlargement of the mitochondria in the endothelium and exhibited a layer of electron-dense fibrillogranular material that had migrated forward through the Descemet membrane. These alterations were similar to the changes observed after photoablation of the cornea by an excimer laser.

CONCLUSION

It was postulated that the extrusion of electron-dense material in the Descemet membrane observed after excimer laser ablation might have occurred primarily not as a result of shock waves, but from destruction of the epithelial integrity.