Human Excimer Laser Keratectomy

OBJECTIVE: To analyze human corneal responses to excimer laser by immunohistochemistry. METHODS: Corneas cultured for 3 weeks after laser ablation or taken from patients 5 to 16 months after laser treatment were exposed to antibodies to beta, integrin; types VII, IV, and III collagen; fibronectin; type I procollagen; and prolyl 4-hydroxylase. Antibody distributions were compared with those of normal corneas and unablated regions of treated corneas. RESULTS: After 3 weeks, distribution of beta, integrin, and types VII and IV collagen was patchy; heavy deposits of fibronectin appeared subepithelially. Keratocytes stained for prolyl-4-hydroxylase and type I procollagen. With increasing postoperative time, fibronectin diminished, and beta 4 integrin and type VII collagen became linear, stromal staining of types III and IV collagen increased and their diminished. CONCLUSIONS: Components of basement membrane, attachment complexes, and stromal matrix are synthesized shortly after laser treatment. Changes in these elements persist for 16 months in the human cornea.