Refractive keratoplasty. Histopathology of clinical specimens.

Two keratophakia (KF), one epikeratophakia (EKP), three myopic keratomileusis (MKM), and three hypermetropic keratomileusis (HKM) specimens obtained 3.5 to 31 months following refractive keratoplasty were evaluated. The corneas were removed at keratoplasty due to postoperative complications, such as corneal edema, irregular astigmatism, delayed reepithelialization, stromal ulceration, epithelial interface ingrowth, and loss of visual acuity. The KF specimens demonstrated viable epithelium in the recipient-donor lenticule interface, disruption of the normal collagen lamellar pattern in the lenticule, and absence of keratocytes. All of the keratomileusis lenticules and the one epikeratophakia lenticule had variable keratocyte repopulation. All specimens showed irregular epithelial maturation. In one case of myopic keratomileusis, ferritin-like particles were found in the epithelial intercellular spaces. Folds in Bowman's membrane were seen in several keratomileusis lenticules; in one case, breaks in Bowman's membrane (BM) were seen.