PURPOSE To test the hypothesis that the surrounding vascular plexus of the lacrimal sac and the nasolacrimal duct contributes to the regulation of tear outflow. METHODS Experiments in 30 probands aged between 15 and 37 years were performed in both nasolacrimal systems of each subject by observing with an endoscope the transit time of an applied tear drop containing fluorescein dye until its e...

A case of squamous cell carcinoma arising from the right lacrimal sac is presented. MR T2-weighted images showed a mass of low signal intensity in the right medial canthus extending into the nasolacrimal duct. This led us to postulate a high-grade malignant neoplasm arising in the lacrimal sac.

Primary nasolacrimal duct malignacy is rare. Only a few tumours have been reported originating from this location including lymphoma, Kaposi’s sarcoma, adenocarcinoma, angiofibroma, and squamous cell carcinoma. Mucosal melanoma represents 1–2% of all melanomas, with 25–50% in the head and neck—that is, upper respiratory tract, oral cavity, and pharynx. Other sites include urinary, female genita...

The primary function of the lacrimal system is to produce and drain the tear film from the surface of the eye. The tear film is composed of three integrated layers: the aqueous, mucus, and lipid layers. The aqueous layer is produced by the orbital lacrimal gland and gland of the third eyelid and secreted onto the ocular surface through ductules that traverse the conjunctiva. The mucus layer is ...