Pathology of the iridocorneal-endothelial syndrome. The ICE-cell.

PURPOSE: The iridocorneal-endothelial (ICE) syndrome is characterized by glaucoma, corneal failure, and iris destruction. Specular photomicroscopy of the corneal endothelium in this disease shows a population of abnormal cells named ICE-cells. Comparison between ultrastructural examination and specular photomicroscopy demonstrates that the histologic equivalent of ICE-cells are cells with an epithelial phenotype. The authors have studied the differentiation markers expressed by ICE-cells using an ultrastructural immunocytochemical technique.

METHODS

Seven keratoplasty specimens from patients with the ICE syndrome were examined by scanning and transmission electron microscopy and light and electron microscopic immunocytochemistry. Comparison was made with three normal corneas. Immunocytochemical studies were performed with monoclonal antibodies to broad-spectrum cytokeratins, cytokeratins 3, 5/8, 8/18 and 19, vimentin, and epithelial membrane antigen.

RESULTS

ICE-cells were morphologically similar to epithelial cells and expressed the same profile of differentiation markers as did normal limbal epithelial cells.

CONCLUSIONS

ICE-cells may arise from an embryologic ectopia of ocular surface epithelium. Alternatively, these findings are consistent with a metaplastic stimulus resulting in a profound change in the phenotype of normal corneal endothelial cells.