What are the Puncta?
The lacrimal punctum is a small aperture located in the slightly elevated eyelid tissue called the lacrimal papilla, at the junction of the lacrimal and ciliary portions of the eyelid margin. A punctum can be found in both the upper and lower lids. The puncta are turned inward toward the globe and can be seen only if the eyelid edge is everted slightly outward. Each punctum opens into a tube, called the lacrimal canaliculus that joins the puncta with the lacrimal sac.
- Puncta play an important role in tear drainage.
- Puncta can be occluded to treat dry eye disease.
- Punctal occlusion may improve dry eye symptoms.
Understanding the Puncta
Tears produced by the lacrimal system move medially with lid blinking. They flow through the lacrimal punctum in each eyelid margin and through the superior and inferior canaliculi in the medial aspect of the upper and lower eyelids. They then drain via the sinus of Maier into the lacrimal sac. The lid acts like a windshield wiper, pushing the tears into the puncta to be removed from the eye.
Occlusion Treatment of the Puncta
Punctal occlusion is a mechanical treatment in which the tear drainage system is blocked to preserve the natural tears on the ocular surface. Punctal occlusion is often used when artificial tears do not improve the patient’s dry eye symptoms. By occluding the puncta, the eye doctor preserves the tears, which improves aqueous tear film quality and quantity.
Semi-permanent silicone or temporary collagen punctal plugs are inserted into the upper or lower puncta or both. Collagen plugs dissolve within four to seven days while silicone plugs either come out spontaneously or are removed by a physician. Permanent occlusion of the puncta is achieved by thermal cautery or argon laser.
Studies show that with punctal occlusion treatment, patient symptoms improve in 74% of eyes at four weeks with a significant reduction in fluorescein staining and use of adjunctive lubrication in the same time period. Patients also report improved contact lens comfort and wearing time after punctal occlusion.
Adverse outcomes of punctal occlusion may include epiphora (overflow of tears), foreign body sensation, eye irritation, and spontaneous plug loss.