Cause of a watery eye
The treatment of a watery eye will depend on the cause.
Common causes include eyelid laxity (ectropion), punctal stenosis, blocked tear ducts and dry eye conditions.
These causes and treatment options are described below.
- Dry eye and reflex watering (reflex epiphora)- occasionally a dry eye can lead to excessive tear production and symptoms of watering. In a dry eye the surface of the eye has insufficient lubrication and becomes exposed. The tear glands then produce an excessive volume of tears as a reflex response. These excessive tears spill out of the eye. This can also occur when the eyelid glands are blocked or inflamed (meibomian gland dysfunction or MGD). In MGD the oily layer of the tear film is deficient and so the tears evaporate too quickly. This is known as evaporative dry eye and can also lead to reflex watering of the eyes.
Reflex watering associated with dry eye often leads to confusion with patients finding it difficult to understand why they have been prescribed artificial tears to improve their watering eye symptoms.
- Eyelid laxity (ectropion) – the lower eyelid can often become lax with ageing and sit away from the eyeball. An eyelid tightening procedure (a lateral tarsal strip or lateral canthopexy) can correct this.
For more information on ectropion correction please click here:link to ectropion page
- Punctal stenosis – this is a narrowing of the tear duct opening within the inner corner of the eyelids (the punctum). This is a common problem and can occur if there is eyelid margin inflammation (blepharitis) or if the eyelid is lax and the punctum sits away from the eyeball (ectropion). A punctoplasty can be performed to enlarge the punctum and thus improve watering from the eye.
- Canalicular stenosis / obstruction – the canaliculi are delicate drainage passages in the eyelids. These convey tears from the puncta (little holes on the inner aspects of the eyelids) to the tear sac. These can become narrowed or blocked up by trauma, infection and some treatments (e.g. chemotherapy for cancer can sometimes cause canalicular obstruction).
- Canalicular obstruction can cause very troublesome watering. The treatment will depend on the location of the blockage and the extent of the blockage. Some patients can have a Crawford silicone stent inserted to widen the narrowed passageways. This may remain in place for up to 3 months and then removed in clinic
- Blocked tear duct (nasolacrimal duct obstruction or NLDO) – this is one of the commonest causes of a watery eye
The nasolacrimal duct is a narrow passageway that allows tears to drain from the tear sac into the nose. A watery eye can result from either a partial or complete blockage of the tear duct.
Blockage of the nasolacrimal duct tends to occur more frequently with ageing and is more common in women. However it can occur at any age. Even some children are born with blocked tear ducts and suffer watery sticky eyes (congenital nasolacrimal duct obstruction).
Blockage of the tear ducts can usually be easily diagnosed at the time of a clinic consultation by performing a syringing of the tear ducts (also known as a “sac wash-out”):
After instilling some anaesthetic drops in the eye a small quantity of saline (salty water) is injected through a fine blunt-tipped tube (a lacrimal cannula).
If the tear duct is not completely blocked then the patient will notice some fluid entering the nose and be able to taste some salty water (saline) in the back of the throat. This test can diagnose a partial or complete obstruction of the tear duct.
Sometimes a special x-ray (a dacryocystogram or DCG) or a radioactive tracing test (a lacrimal scintigram) may be required to identify the cause of the problem. These tests can be useful if syringing fails to demonstrate any obvious obstruction.
Occasionally the blockage in the tear duct can result in an infection in the tear sac (dacryocystitis).
This can cause severe inflammation and discomfort. It can also rarely spread to the eye socket (orbit) and threaten vision.
Dacryocystitis requires urgent treatment with oral antibiotics followed by tear duct bypass surgery (a dacryocystorhinostomy or DCR) a few days or weeks later.