Excessive production or under-drainage of tears leads to tears flowing down the cheeks. This may cause blurring of vision, interfere with daily visual tasks and may be socially embarassing. If severe, this may require the attention of an eyelid and lacrimal specialist
Tears are produced by the lacrimal gland and drained away through fine passages at the inner corner of the eyelids into the nose. Tears are essential in keeping the surface of the eye clear, moist and healthy. Blinking spreads the tears evenly across the cornea which acts as the ‘windscreen’ of the eye to allow us to achieve optimum vision.
The most common cause of excessive tear production (reflex tearing) is caused by Dry Eye Disease (DED). In this case poor quality tears do not sufficiently wet the cornea and nerve fibres on the surface of the eye send signals to the tear gland to produce more and more tears.
Common causes of under-drainage may result from eyelid problems or the narrowing or blockage of tear drainage channels.
A consultation and examination is essential to establish the main cause of the watering eye. This will involve tear duct syringing to test the patency of the tear drainage system.
If the watering is mainly due to dry eye then this has to be treated (refer to Dry Eyes page). If poor drainage is the main cause of the watering then the cause of tear drainage needs to be determined. In some patients, eyelid surgery may be recommended, in others, minor surgery to enlarge the punctum (opening)of the tear duct drainage system (puncto-canaliculoplasty) may be enough to control the watering. In more severe cases a tear duct bypass operation called DCR (DacryoCystoRhinostomy) may be required to bring relief.
External DCR procedure
The DCR operation is performed through a 1-1.5 cm incision on the side of the nose where the scar is often invisible. The surgeon bypasses the narrowing or blockage in the tear duct by joining the lining of the tear sac to the lining of the nose. This newly made passageway is initially kept open by small polythene rods/tubes. These are removed in the outpatient clinic in the ensuing weeks or months after surgery, depending on the severity of the blockage.
Endonasal DCR procedure
In some patients the surgery can be performed endonasally (from the inside of the nose). This avoids an external scar. However this may not be suitable for some types of tear duct obstruction. Again the passageways are kept open by the small plastic rods which are removed later when the rhinostomy (the join between the tearsac and the lining of the nose) has healed sufficiently.
Anaesthesia: The operation is usually performed under general anaesthesia with the patient asleep. Occasionally it can also be performed under local anaesthesia with the side of the nose ‘frozen’ by an injection and intravenous sedation.
Note: All treatment is preceded by a consultation and examination to establish the correct diagnosis.