[Long-term healing of excimer laser ablated rabbit corneas].

PURPOSE

To evaluate histologically and immunohistochemically long-term changes in rabbit cornea following excimer laser ablation.

MATERIALS AND METHODS

Excimer laser keratectomy was performed on 12 eyes of 6 rabbits. The corneas were subjected to histological and immunohistochemical studies 2 and 3 years after treatment.

FINDINGS

In all specimens, epithelial basement membrane of the ablated central cornea showed undulating and spike-pattern invasion into the epithelial side. The collagen lamellae showed irregularities in the subepithelial stroma. Immunohistochemically, the subepithelial stroma showed positive reaction to anti-type III collagen antibody. Staining for anti-IV collagen antibody showed a linear pattern in the epithelial basement membrane and was positive in the subepithelial stroma of the ablated central cornea. These positive reactions to anti-type III and type IV collagen antibodies in the stroma showed the localized presence of scar tissue in the ablated stroma. Antibody to type VII collagen showed weak reaction in the basement membrane, suggesting incomplete regeneration of anchoring fibrils.

CONCLUSION

The healing process was still incomplete 3 years after excimer laser keratotomy in rabbits.