Department of Basic Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad,
In this study ten pairs of superior gland of third eyelid of 10 adult male camels free of apparent ocular disease were examined to compare the normal anatomical and histological properties of these glands. After dissecting, all of the glands were characterized and measured (length and width) on both the left and right side. In the camels, the superior gland of the third eyelid was oval shaped and irregular in outline. The gland was located within the orbit on the medial aspect of the eyeball in animals that possess a nictitating membrane. Posterior surface of the gland was convex and attached to the nictitating membrane. The anterior surface that is contacted with the bulb of the eye was concave. The mean length of the superior gland of the third eyelid was 28.7 ± 2.7 mm and 27.2 ± 2.4 mm in the left and right side, respectively in the anteriorposterior direction. The mean width was 17.4 ± 0.8 mm and 16.1 ± 0.9 mm on the left and right side, respectively in the superior-inferior dimension. There was significant difference between the width of the left and right superior gland of the third eyelid. The mean width of the left superior gland was greater than the right (P<0.05). The histology of the gland revealed secretary units of tubuloacinar and serous with scattered alveolar units. Secretory cells had the typical appearance of serous cells. Tubuloacinar units completely surrounded the hyaline cartilage of the third eyelid. The Masson Trichrome stained connective tissue septae surround the individual acinus and tubules in camel superior gland. Larger sheets of connective tissue with inter and intralobular ducts as well as veins and arteriols were found and separated the gland into lobules.