Long-term histopathologic findings in human corneal wounds after refractive surgical procedures.

OBJECTIVE: To describe the human corneal histopathology after laser in situ keratomileusis, photorefractive keratectomy, astigmatic keratoplasty, clear corneal refractive lens surgery, conductive keratoplasty, and intrastromal corneal ring segment placement.
DESIGN: Retrospective histopathologic study and selected literature review.
METHODS: Ninety-four postmortem corneas from 49 patients and 10 corneal button specimens from 6 patients with previous refractive surgery were collected from eye banks and refractive surgeons in North America. This observational case series evaluated the pathologic findings in the wounds of these corneas in the context of previous studies.
RESULTS: Three histopathologic types of corneal wound-healing responses were present in corneas after refractive surgery. The first was an epithelial cell modification that reestablished a smooth anterior corneal surface through basal epithelial cell hypertrophy, by epithelial hyperplasia, or both. The second was the production of a hypercellular fibrotic stromal scar, and the third was the production of a hypocellular primitive stromal scar. Although only the hypercellular fibrotic stromal scar could be identified on gross examination, all three wound responses were identified with light, electron, and immunofluorescence microscopy. Confocal microscopy also identified these three processes but with less detail and resolution.
CONCLUSION: Understanding the locations, clinical appearance, and functional attributes of these wound-healing responses will help guide evolving techniques or adjunctive treatments.