When tears constantly spill over the eyelid and run down the cheek (epiphora), it signals a failure in the eye’s natural drainage mechanism. This overflow is caused by a blockage within the tear duct system, preventing tears from reaching the nasal cavity. A blocked tear duct can lead to chronic irritation, discharge, and recurrent infections. When less invasive treatments fail to clear this obstruction, the temporary placement of tear tubes, or lacrimal stenting, is used to restore proper tear flow.
The Tear Drainage System and Obstruction
The tear drainage system transports tears from the eye’s surface into the nose. Tears begin at the lacrimal puncta, two tiny openings on the inner corner of the upper and lower eyelids. Tears then move through small channels called canaliculi, collecting in the lacrimal sac next to the nose. The final segment is the nasolacrimal duct (NLD), a tube that passes through the bone and empties into the nasal cavity.
An obstruction, most commonly at the lower end of the nasolacrimal duct, results in Nasolacrimal Duct Obstruction (NLDO). In infants, this blockage is frequently congenital, often due to a thin, unperforated membrane at the duct’s opening (the Valve of Hasner). In adults, obstruction is typically acquired, caused by chronic inflammation from infections, trauma, or age-related narrowing of the drainage openings. When the duct is blocked, tears become stagnant within the lacrimal sac, which can lead to infection and mucous discharge.
Treatment Progression Before Intubation
Treatment for a blocked tear duct begins with the least invasive approaches, especially for infants with congenital NLDO. Initial management involves observation combined with a specific massage technique performed by the caregiver. This gentle external pressure over the lacrimal sac helps rupture the membrane blockage at the duct’s lower end. This method is highly effective, resolving the condition in up to 90% of cases within the first year of life.
If conservative methods fail, or if the blockage is acquired in an adult, doctors may perform lacrimal probing. This involves passing a thin instrument through the punctum and down the nasolacrimal duct to mechanically open the blockage. Tear tube placement, or intubation, is generally reserved for cases where probing has failed to keep the duct open, or when the patient is older than 12 to 18 months, since probing success rates decline with age. Intubation is also used for partial or chronic obstructions in adults to temporarily stent the passage open and prevent scarring and re-closure.
Insertion and Placement of Tear Tubes
Tube placement involves threading thin, flexible silicone tubes through the entire tear drainage pathway to serve as a temporary scaffold. This outpatient procedure requires general anesthesia for children to ensure stillness, while local anesthesia with sedation may be used for adults. The surgeon first passes a probe through the upper and lower puncta, guiding it down through the canaliculi and lacrimal sac, eventually directing it into the nasal cavity.
Once the passage is clear, the silicone tube is attached to the probe and pulled through the system so that a loop of tubing rests securely in the inner corner of the eye. The tubes (often bicanalicular or monocanalicular stents) are then secured in the nose, either tied together or anchored to the nasal wall. This temporary stent maintains the patency of the duct, allowing the tissues around the newly opened channel to heal without sealing shut.
Post-Procedure Care and Tube Removal
Following tear tube placement, patients receive instructions to manage healing and minimize complications. Post-operative care typically includes antibiotic and anti-inflammatory eye drops to prevent infection and control swelling. Patients are advised to avoid rubbing the eyes or forcefully blowing the nose, which could inadvertently dislodge the tube.
The silicone tubes are generally left in place for three to six months to provide sufficient time for the duct lining to stabilize. While the tube is in, some patients may still experience minor tearing or irritation, or even an increase in symptoms until removal. Tube migration, where the loop slips out of the punctum, is a possible complication requiring attention. Tube removal is a straightforward process, often performed quickly in the clinic without general anesthesia. Silicone intubation is highly successful, with reported success rates exceeding 90% in resolving chronic tearing.