3-DIMENSIONAL ORGANIZATION OF COLLAGEN FIBRILS DURING CORNEAL STROMALWOUND-HEALING AFTER EXCIMER-LASER KERATECTOMY

Purpose: To investigate the structural changes in corneal stromal coll agen fibrils after excimer laser keratectomy in relation to the degree of corneal haze. Setting: University of Tokyo Hospital, Tokyo. Japan Methods: Corneal haze was quantitatively measured by analyzing the lig ht scattering in Scheimpflug Images of the corneas of white rabbits af ter excimer laser keratectomy. Collagen fibril structure was examined using scanning electron microscopy after chemical digestion with sodiu m hydroxide solution; the same specimens were examined by transmission electron microscopy after re-embedding.Results: Corneal haze reached a peak 4 weeks after excimer laser keratectomy and the gradually decre ased. The collagen fibrils of the normal cornea were regularly arrange d parallel to the surface of the cornea, with small interfibrillar dis tances. After excimer laser keratectomy, the arrangement was highly di sordered, with increased interfibrillar distances. These structural ch anges were most prominent weeks after excimer laser keratectomy. Concl usion: The structural changes in the collagen fibrils of the corneal s troma, especially the increase in interfibrillar distances and the dis ordered arrangement, were associated with corneal haze after excimer l aser keratectomy.