Ultrastructure of the paralimbal and juxtacaruncular human conjunctiva.

The epithelial fine structure of the juxtacaruncular and the medial paralimbal human conjunctiva was evaluated. In both locations the following types of cells could be identified: (1) basal cells containing numerous intermediary filaments (dark basal cells); (2) basal cells containing many mitochondria (light basal cells); (3) wing cells (spinocytes containing numerous filaments that were fewer and formed smaller bundles than those of the dark basal cells; (4) flattened, dark superficial cells; (5) wing-cell-like superficial cells. In addition, the juxtacaruncular conjunctiva contained the following cell types: goblet cells, light wing cells containing a multitude of polysomes, light wing cells containing dilated profiles of rough endoplasmic reticulum (rare), and light wing cells containing numerous microtubules (rare).