Discipline: Veterinary Medicine
Thirty eyeballs and eyelids from 15 Philippine water buffaloes of both sexes were collected and processed routinely to observe the morphology of the glands of the eyelid. Four glands were identified: superficial gland of the third eyelid, tarsal glands, glands of Moll and glands of Zeiss in the upper and lower eyelids. All four glands were lobulated. The superficial gland of the third eyelid was well-developed, compound tubuloalveolar, encapsulated, and mixed but predominantly serous. The mucous cells secreted neutral and sulfated mucins. The tarsal glands were numerous and better developed in the upper than in the lower eyelid. They were compound tubuloalveolar, encapsulated and sebaceous. The glands of Moll were small, simple coiled tubular, unencapsulated and serous. It presented two types of secretory units: one lined with cuboidal cells and another lined with columnar cells. Cuboidal cell-lined secretory unit presented a wide, regularly scalloped lumen, secretory cells with short, dome shaped apical blebs containing numerous small eosinophilic granules: and round, centrally located nuclei. Columnar cell-lined secretory unit showed a narrow lumen, irregular luminal surface of the epithelium: and secretory cells with elongated apical blebs containing large eosinophilic granules. The glands of Zeiss were structurally similar to the tarsal glands except that they were smaller, unencapsulated, and simple branched, tubuloalveolar with a duct that opened into the hair follicle. The tarsal glands, glands of Moll and glands of Zeiss reacted negatively to PAS and AB pH 2.5. No morphological differences were observed between the gland of the third eyelid, glands of Moll and glands of Zeiss of male and female Philippine water buffaloes.