Lacrimal punctum

Lacrimal punctum on the eyelid

The lacrimal punctum (plural: puncta) is a small opening on the edge of each eyelid near the medial canthus, which is the corner of the eye where the upper and lower eyelids meet. These openings are part of the lacrimal apparatus, which is responsible for the drainage of tears from the eye into the nasal cavity.

Anatomy

Each eye has two lacrimal puncta: one in the upper eyelid and one in the lower eyelid. The puncta are located on the medial (inner) aspect of the eyelid margins. The upper punctum is slightly smaller than the lower punctum and is located near the upper eyelid's edge, while the lower punctum is found near the lower eyelid's edge.

The puncta lead into the lacrimal canaliculi, small channels that transport tears from the surface of the eye to the lacrimal sac. From the lacrimal sac, tears drain into the nasolacrimal duct and eventually into the nasal cavity.

Function

The primary function of the lacrimal puncta is to collect tears produced by the lacrimal gland and direct them into the lacrimal drainage system. This process helps to keep the eye surface moist and free of debris, and it also prevents tears from overflowing onto the face.

Clinical Significance

Lower lacrimal punctum on the eyelid

The lacrimal puncta can be involved in various medical conditions. One common issue is punctal stenosis, where the puncta become narrowed or blocked, leading to excessive tearing or epiphora. This condition can be caused by inflammation, infection, or trauma.

Treatment for punctal stenosis may involve procedures to dilate the puncta or surgical interventions such as punctoplasty. In some cases, punctal plugs may be inserted to treat dry eye syndrome by reducing tear drainage.

Related Pages

• Lacrimal apparatus
• Lacrimal gland
• Nasolacrimal duct
• Epiphora
• Dry eye syndrome