Histopathologic and immunologic aspects of alphacor artificial corneal failure.

PURPOSE: To describe the histopathologic and immunologic characteristics of late artificial corneal failure in a small series of patients who underwent AlphaCor implantation and to elucidate the mechanisms involved.

DESIGN

Clinicopathologic case series.

METHODS

Three patients were diagnosed with corneal melting during the late postoperative period and required the removal of the devices. The explanted devices embedded within the corneal tissues were examined by light microscopy, electron microscopy, and immunohistochemical studies.

RESULTS

Light microscopic examination of the specimens disclosed adequate biointegration with no foreign body response. Immunofluorescence studies of the skirt exhibited expression of inflammatory cytokines such as interleukin-1beta (IL-1beta) and tumor necrosis factor alpha (TNF-alpha), and some interferon gamma (IFN-gamma). The keratocytes stained positively for Thy-1 and smooth muscle actin but negatively for CD34.

CONCLUSIONS

Although these findings confirm the occurrence of biointegration, myofibroblastic differentiation of the ingrowing keratocytes is a prominent feature.