Regional differences in the distribution of cytoskeletal filaments in the human and bovine ciliary epithelium.

The distribution of the cytoskeletal elements cytokeratin 18, vimentin, desmin, glial fibrillary acid protein (GFAP), and actin was investigated in different portions of the ciliary body of human and bovine eyes. Regional differences were found only for vimentin and cytokeratin. In both species, cytokeratin staining was more intense in the pigmented (PE) than in the nonpigmented epithelial (NPE) cells. In contrast, immunostaining for vimentin was more intense in the NPE than in the PE. The most intense immunoreactivity for cytokeratin 18 in the PE and for vimentin in the NPE was observed in the posterior pars plana and the crests of the pars plicata. In the remaining portions of the ciliary body, staining was reduced or absent. Desmin and GFAP were not found in the ciliary epithelial cells, whereas actin filaments occurred in both cell layers in all regions.