Histologic and ultrastructural findings in human corneas after successful laser in situ keratomileusis.

OBJECTIVE To examine the histologic and ultrastructural features of human corneas after successful laser in situ keratomileusis (LASIK) in 2 patients post mortem. METHODS Portions of 4 corneas were processed for histology, transmission electron microscopy, and scanning electron microscopy. RESULTS Case 1 had undergone LASIK 3 months prior to death and case 2 had undergone LASIK 20 months prior to death. A Hansatome (Bausch & Lomb Surgical Inc, Clarement, Calif) microkeratome with a 180-microm plate had been used for case 1 and an Automated Corneal Shaper (Chiron Corporation, Munich, Germany) with a 160-microm plate had been used for case 2. Histologically, the LASIK flap measured 160 microm and 150 microm in thickness in case 1 and case 2, respectively. Corneas from both cases exhibited minor epithelial ingrowth into the wound, reactive keratocytes at the wound margin, irregular collagen fibrils in the wound bed, and severed collagen bundles at the flap hinge. These findings were more pronounced in case 1 than in case 2, and the wound interface was virtually imperceptible in case 2. Additionally, the corneas from case 1 contained periodic acid-Schiff--positive electron dense material and wide-spaced collagen at the wound interface, and there was an absence of corneal nerves. CONCLUSIONS These findings show that changes caused by wound repair that are present at 3 months are minor 20 months after LASIK.