What Is the Lacrimal Punctum?

The lacrimal punctum, also called the puncta lacrimalia, is a small orifice in the anatomical system that produces and clears tears from the eyes. Each eye contains a superior punctum and an inferior punctum — also called an upper punctum and a lower punctum, respectively — on the portions of the eyelid near the inner corner. Malfunctions of the this orifice can cause a watering eye condition called epiphora. The plural of lacrimal punctum is lacrimal puncta.

The tear production and drainage system is called the lacrimal apparatus. Tears are produced by the lacrimal glands above each eye. The tears originate in the upper outside corner of the eye before the blinking of the lid disperses the liquid across the eye's surface.

Excess fluids travel into the superior and inferior lacrimal canaliculi. Each channel commences with its matching lacrimal punctum. The puncta allow the tear to move into the lacrimal sac, which then drains into the nasolacrimal duct.

There are three types of tears produced by the system. The eye is nourished and protected by basal tears, which are produced as frequently as every six seconds. The majority of basal tears evaporate while the remainder drains through the ducts.

Reflex tearing flushes the eye to remove an irritant. This type of tearing occurs when an object or irritant enters the eye. Emotional tearing is caused by signals sent to the eyes from the brain because of heightened emotional states. While basal tearing occurs most often, reflux and emotional tearing produce the most tears at one time.

An improperly positioned or narrowed lacrimal punctum can lead to the condition epiphora. Epiphora occurs when tears overflow from the eye onto the face. An additional symptom is a mucus discharge from the abnormal lacrimal punctum.

Acute epiphora usually does not require treatment, because the overflow is caused by a sudden rapid production of tears that floods out the lacrimal apparatus. Chronic epiphora can be congenital, can be because of a malformation in the apparatus or can occur later in life. The chronic condition can be caused by a blockage of the puncta.

A blocked lacrimal punctum can be treated by an ophthalmologist. The punctum is dilated using numbing drops and a dilation tool. The doctor can then irrigate out the lockage using a syringe filled with a sterile saline solution. The irrigation has proved to be successful when the patient can feel the saline in the nose or mouth, because this indicates that the lacrimal punctum has regained connection to the nasolacrimal duct.