The Fine Structure of Human Conjunctiva in the Perilimbal Zone.

Six human biopsy samples of normal, bulbar conjunctiva from the area adjacent to the limbus were studied with the electron microscope. Cell types were identified as polyhedral cells and goblet cells in the superficial stratum and as columnar cells, melanocytes, and polyhedral cells in the basal stratum of the epithelium. Their fine structural characteristics and intercellular relationships are described. The organization and the cell types of the conjunctiva at this site resemble those of other multilayered, stratified epithelia such as the oral mucosa and the combined stratum germinativum and stratum spinosum of the skin. No signs of keratinization are seen. Micrographs of goblet cells in various states of secretion indicate an apocrine secretory mechanism. Slender cell processes are found throughout the epithelium. They represent either melanocyte extensions or intraepithelial nerve endings in the form of naked axons. Structural elements in the lamina propria consist of connective tissue, nerves, blood and lymph vessels, and various cells. Specimens obtained from tioo eyes of rats systemically perfused with osmium were examined for comparison with the human material. No significant differences were found.