Dr Babak Babsharif, Ophthalmologist, Subspeciality in Cosmetic Eye Surgeries (Oculoplastics), & Strabismus
Member of American Academy of Ophthalmology (AAO)
Member of European Society of Cataract & Refractive Surgery (ESCRS)
Certificate of Ophthalmology from International Council of Ophthalmology (ICO) Cambridge, UK
Medical Degree 1989
Board of Ophthalmology 1997
Subspeciality Degree 2006
Complementary Education in University of Texas, USA

Adult nasolacrimal duct obstruction

Adult nasolacrimal duct obstruction
Watering eyes are a common problem, particularly in older people. A blocked tear duct is the most common cause, but there are a number of other causes. You may not need treatment if symptoms are mild. An operation can usually cure a blocked tear duct. Other treatments depend on the cause.
Who gets watering eyes?
 
Watering eyes (tears rolling on to your cheeks) can occur at any age, but are most common in young babies and in people over the age of 60. It can occur in one or both eyes. 
Understanding normal tears
Just above, and to the outer side, of each eye is a small gland called the lacrimal gland. This constantly makes a small amount of tears. When you blink, the eyelid spreads the tears over the front of the eye to keep it moist.
The tears then drain down small channels (canaliculi) on the inner side of the eye into a tear sac. From here they flow down a channel called the tear duct (also called the nasolacrimal duct) into the nose.
What are the possible causes of watering eyes?
Making too many tears
 Emotion can make you cry.
 Anything that irritates the eye can cause you to make a lot of tears. The watering is a protective reflex to help clear irritants away from the eye. For example: 
o Chemical irritants such as onions, fumes, etc.
o Infection of the front of the eye (infective conjunctivitis).
o Allergy causing inflammation of the front of the eye (allergic conjunctivitis).
o A small injury or scratch to the front of the eye, or a piece of dirt or grit which gets stuck in the eye.
o Eyelashes that grow inwards can irritate the front of the eye. This is called an entropion. (See separate leaflet called Entropion.)
 Thyroid eye disease is an uncommon cause.
Faulty drainage of tears
 Tears may become blocked at any point in the drainage channels: 
o The most common cause of watering eye in adults is a blockage in the tear duct just below the tear sac. This is thought to be due to a gradual narrowing of the upper end of the tear duct, perhaps caused by persistent mild inflammation. If you have a blocked tear duct, not only will you have watering eyes, but the stagnant tears within the tear sac may become infected. If the tear sac gets infected you will also have a sticky discharge on the eye. You may also develop a painful swelling on the side of the nose next to the eye.
o Sometimes the tear duct is not blocked fully, but is too narrow to drain all the tears.
o Less commonly, there may be a blockage within the canaliculi, or the entrance to the small channels (canaliculi) in the inner corner of the eye may be blocked. This may be due to inflammation or scarring.
o Rarely, a polyp in the nose may block the tears from coming out of the tear duct.
 Some babies are born with a tear duct which has not fully opened. This is common and usually clears within a few weeks without any treatment as the tear duct opens fully. See separate leaflet called Tear Duct Blockage in Babies for more information.
 Ectropion. This occurs where the lower eyelid turns outward away from the eye. The ectropion may cause tears to roll off the bottom of the eyelid rather than drain down the canaliculi to the tear sac. See the separate leaflet called Ectropion.
Do I need any tests?
Sometimes the cause is easily identified - for example, infections, ectropion, entropion, and conjunctivitis. If there is no obvious cause revealed by a simple examination, further tests may be advised. These may depend on how bad the watering is, and how much it bothers you.
If a drainage problem is suspected, an eye specialist may examine the tear drainage channels, under local anaesthetic. They may push a thin stick (probe) into the small channels (canaliculi) towards the tear sac to see if it is blocked. If the probe goes as far as the tear sac then fluid can be syringed into the tear duct to see if it comes out in the nose. Syringing may sometimes clear a blockage, but it may only give temporary relief. If there seems to be a blockage then a dye may be injected into the tear duct. An X-ray picture is then taken. You can see the dye in the duct on the X-ray film. It will show exactly where there is any obstruction or narrowing of the tear duct.
Other scans - for example, a CT or MRI scan - may be undertaken in some cases.
What is the treatment for watering eyes?
Treating eye irritation
Quite often the cause can be treated. For example:
 Eyelashes irritating the front of the eye (entropion) can be removed.
 Conjunctivitis can usually be treated with drops.
 Pieces of grit, etc, can be removed.
Treating tear drainage problems
 Ectropion can usually be treated with a minor operation to the lower eyelid.
 Babies with watery eyes usually grow out of it with no treatment.
 Blockage of the channels in adults: 
o You may not need treatment if the watering is mild or does not bother you much.
o A blocked tear duct can be treated with an operation. The usual operation is called dacrocystorhinostomy (DCR). In this operation a new passage is made between your tear sac and your nose and this bypasses any blockage below your tear sac and allows tears to drain normally again.
o DCR surgery is worthwhile if the watering is bad enough to interfere with your activities of daily living. It is also recommended if you have had an infection in your tear sac as a result of the blocked tear duct. The surgery may prevent repeated attacks of a red, painful swelling at the corner of your eye.
o There are two ways of doing this surgery, either externally - through your skin or endoscopically - from within your nostril. Your doctor will be able to give you more information regarding this.
o A narrowed small channel (canaliculus) which is not fully blocked may be widened by pushing in a probe. However, if it is completely blocked, an operation is an option to drain the tears into the nose.

Dr. Bab sharif