A Light Microscopic Study: Conjunctiva-Associated Lymphoid Tissue in Camel

Conjunctiva-associated lymphoid tissue (CALT) is one of the most important accessory component of the eye. This study was undertaken to demostrate the histological distribution and characteristic features of CALT in healhty camels using light microscopy technique. A total upper and lower eyelids of 5 (age range, 13-19) camels were investigated. The gross appearance of CALT were revealed by acetic acid application. Fully intact solitary and aggregated lymphoid follicles were observed as members of CALT in all camels. These follicles were covered by a thin, flattened epitehelium called follicular-associated epithelium (FAE) that contained intra epithelial lymphocytes and lacked goblet cells. In addition germinal centers, corona, subepithelial dome region and interfolliculer areas were noticed within the lymphoid follicles. The presence of high endothelial venules (HEV), a highly distinctive feature of CALT, was confirmed in interfollicular areas. We conclude that CALT of camel closely resembles other mucosal lymphoid tissues and may serve as an important member of ocular defense mechanism with its determinative features