The punctum of the eye is a small opening located on the inner edge of both your upper and lower eyelids, close to the nose. You might notice it as a tiny, slightly elevated spot on the pinkish tissue near the corner of your eye. These minute apertures are typically about 0.3 mm in diameter and serve a specific anatomical purpose.
The Punctum’s Role in Tear Drainage
The punctum serves as the initial opening to your eye’s tear drainage system, often referred to as the lacrimal system. Tears, produced by the lacrimal glands to lubricate and protect the eye, collect in the “tear lake” along the lower eyelid margin. With each blink, your eyelids act like a windshield wiper, pushing these tears towards the puncta.
Once tears enter the puncta, they travel through small tubes called canaliculi, which extend from each punctum. These canaliculi then converge and drain into a small reservoir known as the lacrimal sac, situated between the eye and the bridge of the nose. From the lacrimal sac, tears flow down a duct called the nasolacrimal duct, which empties directly into the back of your nose. This pathway explains why your nose often runs when you cry or experience watery eyes, as excess tears drain into your nasal cavity.
Conditions Affecting the Punctum
When the punctum does not function properly, it can lead to noticeable eye discomfort and symptoms. A common issue is the narrowing (stenosis) or complete closure (occlusion) of one or both puncta. The primary symptom resulting from impaired tear drainage is excessive, persistent tearing, known as epiphora.
Epiphora occurs because tears cannot exit the eye efficiently, causing them to well up and overflow onto the cheek. Several factors can contribute to punctal stenosis or occlusion, including the natural aging process, chronic inflammation of the eyelids, or previous eye injuries. Some individuals may be born with an underdeveloped or absent punctum, a condition known as congenital atresia.
Treatments for Punctal Disorders
Medical interventions for punctal disorders aim either to restore tear drainage or to intentionally block it, depending on the underlying issue. For a blocked or narrowed punctum, procedures such as punctal dilation can be performed, where a specialized instrument gently stretches and widens the opening. In more persistent cases, a minor surgical procedure called punctoplasty may be used to reshape or enlarge the punctal opening.
Conversely, punctal plugs are a common treatment for dry eye disease, where the goal is to keep tears on the eye’s surface longer. These tiny, biocompatible devices are inserted into the puncta to intentionally block tear drainage. They help alleviate dry eye symptoms by preserving the eye’s natural tear film.