Nasolacrimal duct obstruction
‘Nasolacrimal duct’ is the medical term for your tear duct. Your tear duct system consists of an upper and a lower lacrimal duct, which are tiny channels in your eyelids that join together in an area under your eye called the lacrimal sac. The nasolacrimal sac carries tears from the lacrimal sac into your nasal cavity.
Sometimes the tear duct can become blocked, known as nasolacrimal duct stenosis (narrowing in the duct) or obstruction (blockage in the duct). This condition may be present from birth or could be caused by external factors, such as a growth which blocks the duct or inflammation.
If there is any obstacle inside your tear duct system, it will cause tears to drain from your eye into your nasal cavity. As a result, patients have an excessive amount of tears, known as epiphora. If you have an obstruction in your tear duct system, you may also experience pain, redness or pus.
Your doctor may diagnose you using imaging, which is an out-patient procedure. Depending on the imaging method used, your doctor may also be able to see the cause of the stenosis or obstruction as well as its severity. You will be under local anaesthesia for the procedure.
Two possible routes of treatment for nasolacrimal duct stenosis are surgery and minimally invasive techniques. Both types of treatment are performed as out-patient procedures under local anaesthesia. If you choose to undergo surgery, this means you will have a dacryocystorhinostomy, a surgical procedure in which the surgeon creates a new lacrimal duct.
On the other hand, you may choose to have a minimally invasive procedure, using interventional radiology. One interventional radiology technique is to use a tiny balloon to expand the area (known as balloon dilation), which may be accompanied by a mesh metal tube (a stent) being used to support the structure of the duct. In this procedure, an interventional radiologist inserts a catheter into the edge of the patient’s eye and into the affected tear duct, using imaging for guidance. The interventional radiologist then passes a guidewire and a tiny balloon into the duct and then, once the balloon is dilated, the area is gently expanded.