Lacrimal system diseases

The lacrimal system can be structurally and functionally divided into the lacrimal secretion part and the lacrimal drainage part. Lacrimal secretion part: Includes exocrine glands such as the lacrimal gland, accessory lacrimal glands, and conjunctival goblet cells. Lacrimal drainage part (lacrimal passages): Includes the upper and lower puncta, upper and lower canaliculi, common canaliculus, lacrimal sac, and nasolacrimal duct. Its main function is to drain tears into the nasal cavity. Lacrimal system diseases refer to diseases affecting these two parts. They mainly include dacryoadenitis, lacrimal gland tumors, excessive tear secretion, insufficient tear secretion, lacrimal duct obstruction or stenosis, and acute/chronic dacryocystitis. The main symptoms are epiphora (tears overflowing outside the eyelids because they cannot drain into the nasal cavity) or tearing (tears flowing out of the eyelids because the drainage system cannot remove them quickly enough).