The acinar and ductal organisation of the tarsal accessory lacrimal gland of Wolfring in rabbit eyelid

The purpose of this study was to objectively assess the tarsal accessory la crimal gland of Wolfring and its excretory duct by transmission electron mi croscopy (TEM). The upper eyelid of 6 female grey rabbits (2 kg) was fixed in the fully extended configuration with buffered glutaraldehyde. At the ta rsal/orbital portion of the palpebral conjunctiva, a series of prominent ac inar glands were located by both light microscopy and TEM. Cells within the acini were characterised by apical tight junctions and desmosomal connecti ons as well as abundant intra-cytoplasmic osmophillic (secretory) granules. The apical surfaces were profusely decorated with microvilli-like extensio ns. In the vicinity of the acini, and traversing over several millimetres o f adjacent sub-epithelial parenchyma and epithelium, was an extensive syste m of duct-like spaces lined with secretory cells decorated with microvilli. These ducts run a tortuous course within the palpebral conjunctival epithe lium leading to crypt-like termination's along the eyelid inner surface. Th e tarsal accessory lacrimal gland of Wolfring thus has an acinar structure similar to the main lacrimal glands, and its ducts are lined by secretory c ells along the entire tortuous course towards the palpebral conjunctival su rface, where the ducts emerge at multiple points at the tarsal/orbital port ion of the surface. (C) 1999 Academic Press.