Keeping the eyes moist and healthy requires tears. Tears are produced
in the lacrimal glands, some of which are located under the upper
eyelid. Tears drain from the eye into the nose through the nasolacrimal
duct, or tear duct. A blockage of this drainage duct can cause wet eyes
or excessive tearing. A blocked tear duct can also cause mucus buildup
in the eye or ongoing infections in the lacrimal sac where tears
collect. Infections are noticeable as a swelling of the inner corner of
the lower eyelid.
Nasolacrimal duct obstructions can happen with no obvious cause.
Sometimes previous sinus or nose surgery, or facial trauma with broken
facial bones, can obstruct the tear duct.
Lacrimal drainage surgery is called dacryocystorhinostomy (DCR)
and can be performed in different ways. One type of operation is an
external DCR where an incision is made on the side of the nose, where
eyeglasses might rest. A small amount of bone is removed to permit a
new connection between the lacrimal sac and the inside of the nose.
Small plastic tubes are sometimes inserted at the time of surgery to
help keep the newly created opening from scarring shut during the
healing process. The tubing is removed a few months after surgery.
Another type of operation uses a special instrument called an endoscope.
The endoscope is a small tube with a fiberoptic light that facilitates
the creation of a new opening into the nose. Various types of laser
have also been used to perform the DCR operation.
In extreme cases where the tear duct cannot be reopened or repaired, an
artificial tear duct can be implanted. The artificial tear duct is
called a Jones tube and is implanted behind the inner corner of the
eyelid to drain tears into the nose.
(c) 2007 The American Academy of Ophthalmology