How do tears normally drain away from the surface of the eye?
The surface of the eye and insides of the eyelids are mucous membranes which by definition should be moist at all times. This moisture is provided by tears that are made by the lacrimal gland, a specialised gland located under the outer one-third of the upper eyelid. Throughout the day when we blink, the tears are spread across the eye and slowly pushed toward the inside corner next to the nose. On the inside corner of each eyelid there is a small drainage port called the punctum. We can see this opening if we look closely in the mirror and gently pull the lid away from the eye. Each punctum leads to a short horizontal drainage canal (the canaliculus) which leads to a drainage sac deep under the skin at the inner corner of the eye (the lacrimal sac). Finally, this sac drains downwards (via the nasolacrimal duct – the tear duct), through the bone of the side of the nose into the nose. This is the reason why the nose runs when someone cries.
What is epiphora (watery eye)?
Epiphora is an overflow of tears onto the face. A clinical sign or condition that constitutes insufficient tear drainage from the eyes in that tears will drain down the face rather than through the nasolacrimal system.
Causes and treatment of epiphora
Causes of epiphora are any that cause overproduction of tears, decreased drainage of tears or pump failure, resulting in tearing onto the cheek.
Overproduction of tears
Evaporative dry eye, or reflex tearing. A dry eye can result from things like a dry or windy environment; hormonal changes associated with pregnancy, breast feeding or menopause; or inflammation of the eyelid edges (blepharitis). Probably the most common cause of a dry eye are aging changes. This is set off by malfunctioning glands in the eyelids (the Meibomian glands), which normally secrete an oily material that forms part of our tears. This secretion helps retard the evaporation of tears between blinks. When the glands are not functioning properly, the tears evaporate quickly and leave the sensitive cornea exposed. The tear glands then produce an excessive volume of tears as a reflex. In these situations, there are so many tears made that they overflow the normal drainage pathway to the nose and instead spill onto the cheeks. Treatment for overflow tearing is directed at the underlying cause and commonly includes supplemental tear drops (yes, a watery eye is often treated, paradoxically, with tear drops), lid scrubs and warm compresses for blepharitis. There are a variety of artificial tear preparations available. Some patients prefer one over another for their own reasons, so it is a good idea to try different preparations. If the tears need to be used more frequently than four times a day it is better to choose a preparation that is free of preservatives. If artificial tears do not adequately relieve the discomfort of dry eyes, closing the openings of the tear drainage system can help to keep more moisture on the eye, making it feel less sore and gritty. The closure can be performed temporarily, with the insertion of silicone plugs, or more permanently, with surgery. In either case, the procedure is carried out under local anesthetic.
Decreased drainage of tears
Narrowing/ blockage along the lacrimal drainage system
Any narrowing, irregularity, or obstruction along the lacrimal drainage system may lead to a wet or watery eye, either in specific conditions (such as cold, windy weather), or on a more constant basis. Other common symptoms include mucous buildup at the inside corner of the eye and/or along the lashes, and distorted vision. Dr Mavrikakis can perform tests to determine if there is a narrowing or blockage and if so, where between the eye and nose the problem lies. The exact location of the narrowing or blockage will determine what treatment options are available to you. In most cases, a surgical procedure will be required to either alleviate or bypass the obstruction.
Narrowing of the punctum or canaliculus may respond to minor procedures to reopen these passageways i.e. snip punctoplasty or stenting procedures.
A common location of blockage is the nasolacrimal duct (nasolacrimal duct obstruction). This causes tears to be trapped in the lacrimal sac and sometimes become stagnant and infected (a condition referred to as dacrocystitis). It is a painful condition that requires oral antibiotics. If the nasolacrimal duct is narrowed (also known as “stenosis”) but still partially open, Dr Mavrikakis may recommend placing temporary stents through your nasal passageways. If this is not effective or if the nasolacrimal duct becomes completely blocked, a dacrocystorhinostomy (DCR) is the gold standard surgery to correct this problem. The procedure has a very high success rate (reduction of symptoms in at least 90% of individuals in the hands of experienced oculoplastic surgeons). A DCR creates a new pathway between the lacrimal sac and the inside of the nose, by removing a thin bone between them. Any blockage or narrowing of the nasolacrimal duct is completely bypassed with this surgery.
A DCR has traditionally been performed through a small skin incision at the side of the nose (external DCR). Nowadays, it can also be carried out through the nose (endonasal DCR). Endonasal DCR avoids a skin incision and the results are pretty much equal to external DCR. Endonasal DCR may not be a suitable procedure if the obstruction is not in an appropriate location or there is a problem within the nose. Dr Mavrikakis carries out both external and endonasal DCRs and will recommend the best approach for you.
Medications either containing, or being similar to, Aspirin, need to be stopped 2 weeks before surgery as long as your doctor confirms that it is safe to do so. Anti-inflammatory medicines should also be avoided for 2 weeks before surgery. If a patient has been prescribed these or any other blood-thinning drugs (such as Warfarin or Clopidogrel), your doctor will need to be contacted to determine if it is safe to discontinue these medications prior to surgery to reduce the risk of bruising and a post-operative nose bleed, which, although rare, can be severe. Paracetamol does not affect bleeding and can be taken before and after this surgery.
A fine, soft silicone stent may temporarily be left in the new tear drain for a few weeks to keep the duct open while healing occurs. The operation takes about one hour, is an outpatient procedure, and can be performed under a general or local anesthetic with intravenous sedation. After surgery, to reduce the chance of a nose bleed, hot drinks are avoided for 24 hours, and there should be no nose blowing or strenuous exercise for 2 weeks. If sneezing is unavoidable, pressure should not be allowed to build up in the nose. It is advisable to sleep on an extra pillow or two for the first few nights, and driving (including operating heavy machinery), alcohol, and sedative drugs should all be avoided for at least 24 hours. If the eye pad has not been removed in the hospital then it should be removed the next morning at home. Normal washing is permissible, with care taken to avoid rubbing the eye. The wound should be kept uncovered.
The first review occurs 1-2 weeks after surgery, when the skin stitches (external DCR) are removed and the eye examined. At the second clinic visit 6-8 weeks after surgery the silicone stent is removed and no further routine review is necessary in most cases.
Many patients continue to have a watery eye for some weeks after surgery until the swelling and inflammation settles, and the silicone stent in the nose is removed. Although the skin incision heals over a few weeks, internal swelling and healing may take many months to settle, and thus some occasional watering can persist for several months after surgery.
The main complications following a DCR include: nose bleed, swelling, scar formation, infection and further surgery.
A nose-bleed may occur in about 2% of patients within the first 10 days after surgery. In most cases the bleeding will stop spontaneously.
The degree of swelling over the inner corner of the eyelids after surgery can vary markedly, some reporting little or none, and others experiencing some swelling and bruising which takes up to a week to settle (the latter being unusual).
The incision on the side of the nose (external DCR) typically settles very well, becoming visually insignificant in time in most patients. However, in about 1 – 2 % of patients, the linear scar is visually troubling, and may require local massage to soften it.
Infection is a rare complication of surgery and is treated with antibiotics.
Rarely, the normal healing reaction in the nose can lead to the formation of a fine membrane across the internal opening, with recurrence of the original watering symptoms. Over half of such patients respond to removal of the membrane and reinsertion of the silicone stent in the nose under a brief general anesthetic. In other patients (and especially if there has been previous trauma), the procedure described above is inadequate to allow tears to drain into the nose. In this situation, the only way to drain the tears is to insert a small, smooth, Pyrex glass tube (often referred to as a Lester Jones tube) through the inner corner of the eyelids to the nose (without any further skin incision) under a brief general anesthetic. This tube remains permanently in place, although it can move slightly with blinking. Although requiring an annual review in clinic, and periodic repositioning in some patients, a Lester Jones tube can be highly effective.
A less common site of complete blockage is at the level of the canaliculus. In this situation, the solution to the problem is the placement of a Lester Jones tube (see above).
Most patients experience resolution of their tearing and discharge once the appropriate procedure has been done to address the blockage in their tear drainage system.
Approximately 7% of infants are born with congenital obstruction of the tear drainage system in one or both eyes. This percentage is even higher in premature infants. Initial treatment involves massaging the area around the affected lacrimal sac to force the tears down the nasolacrimal duct, and to push open the membrane causing the obstruction. Dr Mavrikakis may also prescribe oral antibiotics, drops, or ointment.
If massage does not relieve the tearing, additional treatments might be necessary. Dr Mavrikakis may be able to open the blockage by inserting a thin metal probe through the punctum and down the nasolacrimal duct into the nose. This outpatient procedure is performed under a general anesthetic.
For severe or recurrent cases, additional options include physically dilating the nasolacrimal duct with a balloon, propping the nasolacrimal duct open with a temporary silicone stent, or surgically creating an alternative drainage pathway for tears to pass into the nose (dacrocystorhinostomy).
Most patients experience resolution of their tearing and discharge after treatment is completed, with little if any postoperative discomfort.
If the lids are malpositioned (entropion, ectropion etc) or weak or loose from age (eyelid laxity), paralysis (facial nerve palsy) or injury, they may not blink as well. Without a proper blink mechanism, the tears have a hard time finding their way to the drainage port at the inside corner. In this situation, Dr Mavrikakis will advise on the appropriate surgical procedure to correct the underlying condition and improve the drainage mechanics.