Blocked tear duct – Obstruction of the tear ducts
The term “blocked tear duct” is frequently used by patients to describe chronic tearing. Fortunately, not all tearing is caused by a blockage of the tear drainage system. Tears drain from the inner corner of the eye, and the tear duct runs down the bridge of the nose to the nasal cavity. This is why our noses run when we cry! If a tear duct is blocked, the obstruction may be at the superior meatus (entrance), the duct itself (pathway), or the inferior meatus (exit). An ophthalmologist specializing in the tear ducts, called an oculoplastic surgeon, assesses the blockage. Treatment involves mechanical dilation, stenting, or shunt surgery.
What is a blocked tear duct?
The term "blocked tear duct" is medically referred to as "obstruction of the tear duct".
The term refers to all causes of obstruction, stenosis or narrowing located at the entrance, in the path, or at the exit of the lacrimal canal.
It results in excessive tearing and tear stasis, leading to recurrent eye infections.
Functioning of the lacrimal ducts
Tears come from your lacrimal glands located at the upper outer corner of each eye, below the rim of the orbit.
Tears flow onto the surface of the eye to lubricate and protect it. With each blink, tears and impurities are gradually pushed towards the inner corner of the eye.
They then flow out at the lacrimal puncta (points) located at the inner corners of the upper and lower eyelids.
The tears then pass through horizontal channels (canaliculi) to the lacrimal sac. The lacrimal sac acts as a reservoir before draining into the nasolacrimal duct.
The duct empties into the nasal cavities, which lubricate the nasal mucosa and its secretions. The nasal mucosa absorbs some of the tears, some flow down the throat, and the rest evaporates during respiration.
Causes
The various causes of tear duct obstruction in adults are:
Meatal stenosis – The sphincter located at the entrance of the lacrimal ducts narrows.
Stones – Small calcified clots in the tear ducts.
Facial trauma , including fractures of the nasal bones.
Tumors of the lacrimal ducts or located nearby (rare)
Craniofacial malformations – Particularly in cases of Down syndrome.
Case of a child's tearfulness
A baby can be born with a blocked tear duct. This is called congenital obstruction of the nasolacrimal duct.
10 to 20% of newborns are born with a blocked tear duct; this is actually due to an immaturity of the valve of Hasner, the "one-way valve" separating the nasolacrimal duct from the nasal cavities.
Therefore, excessive tearing in children is almost always linked to an obstruction of the tear ducts.
In 95% of cases, the problem resolves spontaneously, without treatment, within the first year of life. Therefore, therapeutic abstention is recommended before the age of one.
The main symptom, but also the main complaint of the patient when there is an obstruction of the tear duct, is excessive tearing.
Blurred vision linked to an increase in the tear lake is also frequently reported: the eye is bathed in too many tears.
Chronic obstruction of the lacrimal ducts is prone to tear maceration.
If these become infected on the surface of the eye, you will suffer from conjunctivitis .
If tears pool in the lacrimal sac, it will become infected; this is dacryocystitis . The disease manifests as painful swelling of the inner corner of the eye, periocular edema, and purulent discharge from the meatus.
Diagnosis
The diagnosis of a blocked tear duct is clinical.
The ophthalmologist can perform a patency test to confirm the obstruction. For this, the lacrimal meatus is dilated using a small probe, then saline solution is injected.
If you feel the serum flowing down your throat, then the tear duct is open.
If the serum refluxes and runs down your cheek, then the obstruction is confirmed.
To determine the cause and location of the blockage, your ophthalmologist may order a dacryocystogram. A contrast agent is injected through the tear duct, and the scan is performed. This examination can reveal stones and tumors of the tear ducts.
Treatment and surgery
The technique for clearing a blocked tear duct depends on its cause! Medical treatments rely on probes and dilation.
Treatment of meatal stenosis
In cases of stenosis of the lacrimal meatus, that is, at the entrance to the tear ducts, the ophthalmologist may suggest:
A meatal dilator – a small, invisible, transparent silicone tip that “forces” the opening of the lacrimal meatus. The tip eventually falls off on its own, leaving the meatus open.
A surgical opening – Called a “snip”, the surgeon widens the lacrimal meatus by slightly cutting the inlet sphincter.
Treatment of canal obstruction
In case of canal obstruction, particularly by stones, it is possible to perform:
An endonasal probing – A camera is inserted into the nose, the inferior lacrimal meatus is widened, and a probe is passed into the lacrimal duct. The stones are then gradually removed.
A dacryocystorhinostomy (DCR) – The procedure involves directly connecting the lacrimal sac to the nasal cavity to bypass the obstruction. The procedure can be performed through the inner corner of the nose or via an endonasal approach.