Assessment of corneal alterations following laser in situ keratomileusis by confocal slit scanning microscopy

This investigation was done to evaluate in vivo changes in corneal micromorphology occurring after laser in situ keratomileusis. By means of confocal microscopy, nine eyes of eight patients showing uncomplicated wound healing at 2-16 weeks after surgery and one eye of one patient at 30 weeks after initial surgery who had to undergo two retreatments because of a central island were examined. Video recording was used to register the data. The distribution of scattered light in the treated corneae was registered with the z-scan of the microscope. Slit-lamp findings obtained several weeks postoperatively showed only minor corneal alterations. Confocal microscopy revealed morphological changes as a result of the surgery, especially in the epithelium and in the anterior stroma. With the z-scan an additional peak determined by higher reflectivity in the anterior stroma was found. The retreated patient showed marked folds in the area of the interface and flap. Confocal in vivo microscopy is suitable for the noninvasive detection of micromorphological alterations following refractive corneal surgery and for observation of the postsurgical wound-healing phase, including nerve regeneration.