Lacrimal punctum

Lacrimal punctum (also known as tear duct) is a small opening located in the inner corner of the eyelid. It is part of the lacrimal apparatus, which is responsible for the production and drainage of tears. The lacrimal punctum serves as the entry point for tears into the nasolacrimal duct, which then drains into the nasal cavity.

Anatomy

The lacrimal punctum is found on both the upper and lower eyelids, near the medial canthus (the point where the eyelids meet). Each punctum is a small, round or oval opening that leads to a canal known as the canaliculus. The canaliculi of the upper and lower eyelids join to form a common canaliculus, which then drains into the lacrimal sac. From the lacrimal sac, tears flow down the nasolacrimal duct and into the nasal cavity.

Function

The primary function of the lacrimal punctum is to drain tears from the surface of the eye. This helps to keep the eye moist and free of dust and debris. The tears then flow through the lacrimal apparatus and into the nasal cavity, where they are either reabsorbed or expelled.

Clinical significance

Conditions that affect the lacrimal punctum can lead to problems with tear drainage, resulting in symptoms such as excessive tearing (epiphora) or dry eye (keratoconjunctivitis sicca). These conditions can include punctal stenosis (narrowing of the punctum), punctal occlusion (blockage of the punctum), and dacryocystitis (inflammation of the lacrimal sac).

Treatment for these conditions can involve procedures to widen the punctum, insert punctal plugs, or create a new tear drainage pathway (dacryocystorhinostomy).