CORNEAL WOUND-HEALING AND NERVE MORPHOLOGY AFTER EXCIMER-LASER IN-SITU KERATOMILEUSIS IN HUMAN EYES

BACKGROUND: Our aim was to describe wound healing and nerve regenerati on in the human cornea after excimer laser in situ keratomileusis. MET HODS: Excimer laser in situ keratomileusis was done in three human eye s 8 days, 54 days, and 4 months prior to enucleation. Acetylcholineste rase reaction was used to histochemically demonstrate the corneal nerv es. Immunohistochemical methods were used to demonstrate the following wound healing proteins: cellular fibronectin, tenascin, transforming growth factor-beta 1, and alpha-smooth muscle actin. RESULTS: All corn eas healed without complication. No epithelial hyperplasia appeared an d the Bowman's layer was smooth and acellular. An epithelial plug exte nding up to 100-300 mu m under the flap margins was seen in all specim ens, Regenerative nerve fiber bundles emerging from sharply cut anteri or stromal nerves were observed, but the deeper nerves were normal. Re stricted expression of fibronectin and tenascin was found at the wound area, All corneal cell types were positive for transforming growth fa ctor-beta 1 antibody. Cells lining the limbal vessels were positive fo r alpha-smooth muscle actin antibody whereas the corneal cells were ne gative, CONCLUSIONS: The nerve morphology showed only a few abnormalit ies, especially in deep stromal nerves. Epithelial plugs at the flap m argins may maintain a delayed wound healing process for several months but otherwise the process remained active for a relatively short time .