Histological Evaluation of Corneal Scar Formation in Pseudophakic Bullous Keratopathy

PURPOSE: To evaluate histological changes in the corneal stroma in pseudophakic bullous keratopathy. METHODS: Twenty-eight patients (28 eyes) with pseudophakic bullous keratopathy underwent therapeutic penetrating keratoplasty at Shandong Eye Institute between January 2006 and November 2011. The patients were divided into two groups according to the duration of bullous keratopathy (<1.0 year group or >1.0 year group), and three buttons from enucleated eyes with choroidal melanoma served as a control. In vivo confocal microscopy examination, hematoxylin–eosin, Masson's trichrome stain and Van Gieson staining were used for microscopic examination. The histological evaluation and scoring of the buttons for morphological changes, including the degree of stromal scars, neovascularization and inflammatory cells within the corneal buttons, were compared. To study the underlying mechanism, connective tissue growth factor (CTGF) and TGF-β immunohistochemistry were performed. RESULTS: Confocal microscopy examination and histological evaluation and scoring of the buttons showed that compared with the <1.0 year group, stromal scars, neovascularization and inflammatory cells were more severe in the >1.0 year group (P<0.05). There was an increase in CTGF- and TGF-β1-positive stromal cells in the >1.0 year group. CONCLUSIONS: During the progression of pseudophakic bullous keratopathy, stromal scars occurred more often in the patients that had a longer duration of disease. Cytokines such as CTGF and TGF-β1 may play a role in this pathological process and deserve further investigation.