The watery eye
Eyes water to keep the cornea moist and healthy; tears are produced by the lacrimal glands located outside the upper eyelid and along the inner surface of the lower eyelid. They are spread across the eye by blinking and carried along the lower edges of the eyelids to small channels which lead to the tear ducts.
Watery eye, also known as epiphora, is the excessive watering of the eyes that can interfere with the patients daily life. It is mainly caused by the blockage of tear ducts or infection of the eye and can lead to tears spilling down the cheeks instead of being carried back into the tear ducts.
What are the symptoms of watery eye?
Watery eye can affect one eye (unilateral) or both eyes (bilateral). Typically the symptoms of watery eye are excessive tearing which is worse outdoors and can be aggravated by cold or windy weather. Blurry vision due to excessive tear production, irritated eyelids and lumps or redness in the corner of the eye are also common. There may also be some excoriated skin under the eyes.
Who does watery eye affect?
Watery eye can occur in all age group. Around 5% of babies are born with excessive eye watering. The condition is more common in middle-aged patients but may also occur in older patients, mainly due to dry eye which can lead to the over production of tears.
What causes watery eye?
The most common cause of watery eye is the blockage of the drainage pathway and excessive tear production linked to irritation, dry eye, blepharitis or lower eyelid lax.
- Blepharitis: Blepharitis is the inflammation of the eyelash follicles which causes the overgrowth of bacteria usually found on the skin. It can occur due to a combination of both seborrheic dermatitis and bacterial infection. Less commonly allergies or eyelashes infected with lice can cause blepharitis.
- Conjunctivitis: Bacteria, chemical exposure, chlamydia, fungi and certain diseases can cause conjunctivitis which can lead to watery eye. The viral infection of the conjunctiva (‘pink eye’) is especially common amongst children.
- Obstruction of the nasolacrimal duct: Watery eye can also be caused by a partial or full blockage of the tear duct (nasolacrimal duct), which carries tears from the lacrimal sac to the nasal cavity. Blockage can be due to weak eyelid muscles, reduced blinking, infection or a tumour (a ‘polyp’).
- Irritation: Anything that irritates the eye - such as an allergy or ingrown eyelash - can cause watery eye. If the cause is in ingrown eyelash it can been removed if it causes significant discomfort. Irritation due to grit, sand, abrasions or eye drops are easier to treat and require less attention than an ingrown eyelash.
- Ectropion (Lower eyelid lax): If the lower eyelid droops forward or sags tears may not be transported into the drainage system and can overflow to the cheeks.
- Blocked canaliculus: The canaliculi is a small channel located at the corner of the eye just before the tear sac. A blocked canaliculus can be due to inflammation or scaring and is a less likely cause of watery eye.
Complications of watery eye
Although watery eye is not entirely bothersome in most causes, the blocked tear duct can become infected (acute dacrocystitis). Tears trapped in the tear duct can stagnate and become prone to infection causing discomfort as well as irritation.
An infection of this kind requires bathing of the tear sac with warm water 3 - 4 times a day. Antibiotics may also be prescribed by a GP or, in more severe cases, patients may be required to see the emergency eye department as the infected tear sac may need draining.
The infection can pass but may still leave the eyes watering as infection can damage the tear drainage which may require a DCR operation.
Treatments for watery eye
Essentially a full eye examination is required to identify the cause of watery eye. Treatment depends on the cause - irritation, for example, can be treated much quicker and easily than blepharitis. For children with blocked tear ducts massaging can be performed to open the tear ducts rather than surgery as the tear ducts have not fully developed.
Types of Surgery for watery eye
Surgery may also be required to relieve the blocked tear ducts. When surgery is necessary a fluorescein dye is injected into the tear ducts so the obstruction becomes visible on an x-ray scan.
Minor operations can clear the blockage if it is closer to the opening; a blockage further down, however, requires dacryocystorhinostomy to bypass the blockage by directly opening the tear duct into the nose. This can be done under local anaesthetic with sedation or general anaesthetic.
DCR Operation (Dacryocystorhinostomy)
A DCR operation creates a channel from the tear sac to the nose. This type of surgery if performed on patients who are younger or middle aged and experience dry eye 7 - 10 times throughout the day. The skin is cut above the tear sac and small hole in made into the bone to connect the tear sac and the nose. DCR normally requires the patient to stay overnight in hospital.
Balloon dilatation is normally not available due to a low success rate but is an alternative to DCR operations. For this operation, small balloons are placed into the blocked tear duct and blown up to expand area and clear the blockage.
Syringing and Probing
Normally this is used to locate the site of the blockage. However, if the blockage is further up, a probe can be used to clear the disruption but does not show the same success rates as DCR operations.
Surgery normally results in most patients experiencing immediate resolution of watery eye with little to no post-opt discomfort.
Other Treatments for watery eye (Non-Surgical)
Treatments for causes such as conjunctivitis can often be relieved with tear drops which is also the case for grit or other irritations in the eye. Other patients find that watery eye is not bothersome to them and will seek no medical treatment at all.