Patients will frequently present with "a watery eye" or "a tearing eye." Historically, this was called epiphora, but there have been recent variations in the use of different terms.
Lacrimation (or lachrymation) is derived from "lacrima," Latin for tear, and essentially means "production of tears," although it is often used to describe the "shedding of tears," or to cry. Lacrimation may be basal (basic tear production), reflexive (to stimuli such as surface irritation, glare, corneal ulcer, corneal exposure), and psychic (emotional). It is thought that animals do not exhibit emotional lacrimation, although recent observations of elephant mothers responding to their dead offspring have reignited this debate. The sympathetic innervation to the lacrimal gland is thought to stimulate basal tear secretion. Basal tear production decreases with increasing age resulting in progressive acinar atrophy, fibrosis, and lymphocytic infiltrates. Normal basal tear production is 2 microliters per minute (10 ounces per day). It may be stated that lacrimation, whether used to imply "production of tears," or tearing from emotion or stimuli implies the production of tears in a normal person without and blockage of the excretory system.
Epiphora: English texts from at least 1475 have used epiphora to mean tearing or excessive tearing and essentially means an overflow of tears from the eye onto the face that is abnormal. The cause is not specified. There has been a tendency, of late, to apply the word epiphora only to tearing caused by an obstruction. This does not have any historical accuracy, and the temptation to use it in this manner should be resisted.
The word derives from ancient Greek, epifora: "epi" means "on," "upon," or "in addition" and "phérein," meaning "bring" or "carry." The literal meaning of the word epiphora is "to bring upon." This symptom is known to have been described in Egypt (1500 BC) and by Hippocrates (460 BC to 370 BC). Epiphora applies to excessive tearing caused by excessive tear production or secondary to poor drainage. Epiphora is sometimes subdivided into
Plerolacrima: Patients often present with the complaint that they have "a pool of tears in the eyes that interferes with vision," but not frank epiphora. This is also sometimes seen in patients after a dacryocystorhinostomy where the tear flow may be improved, but the obstruction not completely corrected. Ian Francis, a classically trained and thinking surgeon, coined the term "plerolacrima" in 2002. He derived it from the Greek "plero" (meaning full), and the Latin "lacrima" (tears). He noted that it was a similar derivative to the one H. M. Traquair of Edinburgh coined in 1927: "plerocephalic edema," to indicate optic nerve edema caused by raised intracranial pressure. We feel this is a useful term that completes the types of excessive tearing or pooling of tears that bother patients and deserving of an addition to our medical lexicon.
Symptoms: Epiphora can cause blurry vision, discharge if there is a lacrimal sac infection, mucoid discharge if there is a canalicular foreign body, eyelid skin excoriation from constant wiping and laxity of the lower eyelids from constant wiping
The tear film is comprised of three layers:
The mucin layer creates a wettable surface on the cornea. The aqueous layer provides a smooth surface and hydration. The lipid layer reduces surface tension and increases tear break-up time. Tears are secreted at a basal rate as well as reflexively in response to stimuli. Dysfunction of any of these components contributes to surface disease and abnormal tearing, resulting in discomfort, altered light refraction, and blurred vision.
The lacrimal system has secretory and excretory components. Normally, there is a balance between the production of tears and drainage of tears. When this balance is affected, either the secretory or the excretory component may produce epiphora.
The secretory lacrimal system produces tears. The main lacrimal gland sits in the lacrimal fossa of the frontal bone, divided into orbital and palpebral lobes by the lateral horn of the levator aponeurosis. Accessory lacrimal glands sit in the fornices and eyelids. The trigeminal nerve, the facial nerve, sympathetic innervation, and parasympathetic innervation stimulate tear production from the lacrimal glands.
The Secretory System is composed of (fig 1):
The anatomical excretory lacrimal system drains tears. Tears drain from the ocular surface via puncta located in the lower and upper eyelids, into the ampulla, and then through the canaliculi. In 90% of people, the upper and lower canaliculi join to form a common canaliculus. The canaliculi drain into the lacrimal sac, followed by the nasolacrimal duct, which opens in the inferior meatus of the nose. Blockage can occur within any of these components. Both positive pressure and negative pressure systems have been proposed as mechanisms of tear flow through the excretory lacrimal system.
The anatomical excretory system (the punctum, the canaliculus, and the common canalicular opening are termed the upper lacrimal system, and the lacrimal sac and the nasolacrimal duct are termed the lower lacrimal system) is composed of (figs 2, 3):
Functional Excretory System
As one blinks, there is a contraction of the orbicularis oculi muscle: the pretarsal snd preseptal orbicularis muscles have a deep medial head each. The contracture causes dilatation of the lacrimal sac and a suctioning effect. The lower eyelid rides upwards, and the punctum moves inwards. Tears are drawn into the punctum, canaliculus and lacrimal sac by this pump mechanism. This pump mechanism is disturbed in the presence of facial nerve palsy.
The etiology of epiphora is divided into:
Epiphora in adults is a nonspecific finding, representing a broad array of diseases that can cause excessive basal tearing or excessive reflexive tearing secondary to decreased basal tearing. Frequently, more than one factor may cause epiphora. Patients will frequently complain that their eyes tear when they are in the wind or cold: this type of tearing can be seen in normal eyes, in the presence of keratitis sicca, or partial nasolacrimal duct obstruction. Tearing that occurs when indoors is often caused by lower eyelid malposition or nasolacrimal outflow obstruction. In general, older patients are likely to have more eyelid malposition and multiple factors as causes of the epiphora. In younger patients, eyelid malposition is less common: nasolacrimal duct obstruction punctal stenosis or canalicular obstruction is more common. Nasolacrimal duct obstruction affects women more than males (65% to 73%). This is thought to be because of the narrower nasolacrimal ducts, and the longer lacrimal canals are the cause of this increased female preponderance. Epiphora in infants is most commonly caused by congenital nasolacrimal duct obstruction (NLDO).
Epiphora may be unilateral or bilateral. Unilateral epiphora is more likely to be caused by local conditions (nasolacrimal duct obstruction, foreign body). 75% of cases of nasolacrimal duct have unilateral obstruction. Bilateral epiphora may be caused by oversecretion of tears, as seen in keratoconjunctivitis or allergies. Eyelid malpositions are also more often seen in patients with bilateral epiphora. Bilateral epiphora can also be caused by local conditions, which may result in more epiphora on one side.
Epiphora is a common problem in children. In a large epidemiological study, MacEwen et al. found the prevalence of epiphora to be 20 percent in the first year of life in British infants. Interestingly, 95% of these children presented with symptoms by age one month. With age, there is an increase in the number of patients who present with epiphora because of age-related laxity of the lower eyelids, increasing incidence of nasolacrimal duct obstruction, and other associated diseases (facial nerve palsy). Nasolacrimal duct obstruction causing epiphora is more common in women. The incidence of nasolacrimal duct obstruction is 20.24 per 100,000. Nasolacrimal duct obstruction accounts for 31.8% of patients presenting with chronic epiphora. Nasolacrimal duct obstructions cause 67.6% of all lacrimal pathway obstructions.
The following factors need to be determined when a patient presents with epiphora:
Examination of the Eyelids
Examination of the Conjunctiva, Plica Semilunaris, and Caruncle
Examination of the Cornea
Functional Nasolacrimal Obstruction
When a patient complains of tearing but the lacrimal outflow system is patent to irrigation, it is termed "functional epiphora" or "functional obstruction." This type of epiphora may be seen in patients who have had no trauma or surgery or may be seen after a dacryocystorhinostomy has been performed. Even if the lacrimal system appears to be open on irrigation, it is possible that there may be an anatomical narrowing of the lacrimal passage, either in the form of partial nasolacrimal duct obstruction (or narrowing), canalicular scarring, common canalicular scarring, or abnormal irregularities or "valves" which can be caused by scar tissue after dacryocystorhinostomy. To assess the true patency of the lacrimal system, it is necessary to perform a dacryocystogram (DCG).
When assessing a patient with epiphora, underlying orbital, sinus, or adnexal diseases should first be excluded. In particular, eyelid abnormalities (laxity, retraction, ectropion, entropion, trichiasis, etc.), and punctal stenosis or punctal malposition are properly assessed and excluded. Once this has been done, irrigation of the lacrimal system may be undertaken. If the irrigation shows patency, but the patient has epiphora, a dacryocystogram will show any underlying anatomical narrowing or delay inflow.
If irrigation of the lacrimal system shows an obstruction, it is important to determine the type of obstruction. If there is a retrograde flow of fluid through the same canaliculus that is being irrigated, it indicates a canalicular obstruction. The level of obstruction can be determined by probing the canaliculus with a Bowman probe. If the fluid flows back through the opposite canaliculus, it indicates an obstruction in the nasolacrimal duct. As the canaliculi do not always open via a common canaliculus, common canalicular obstruction can be difficult to determine without a dacryocystogram. If there is a common canalicular obstruction, fluid will flow back out through the canaliculus being irrigated. This finding is seen more often after scarring at the common canaliculus seen in a failed dacryocystorhinostomy.
Dry Eye as a Cause of Epiphora
Multiple factors cause dry eyes, and there is also an inflammatory component. Two main types of dry eyes are recognized:
Patients may present with burning, itching, blurry vision, and a sensation of scratchiness and discomfort that is often worse first thing in the morning. Patients with dry eyes will have tear film instability and tear hyperosmolarity. The normal tear balance in an eye comprises the following:
Tear film instability results in loss of tears by evaporation, which in turn stimulates corneal and conjunctival neurosensory receptors. This causes reflex tearing by stimulation of the lacrimal gland. Similarly, meibomian gland dysfunction can lead to abnormal lipids with a poor tear breakup time, increased evaporation, an increase in osmolarity, and an unstable tear film. This can cause increased growth of bacteria along the eyelid, it causes ocular surface inflammation and increased evaporation. Although the Schirmer's test without topical anesthesia is used to measure reflex tearing, many patients with dry eyes will have normal Schirmer's test results. A tertiary referral oculoplastic practice found that dry eyes caused epiphora in 40% of their patients. This a higher percentage of patients than formerly thought. Because of travel, lifestyles, living in dry climates, increasing use of computers and screens, and prolonged close work, more patients are presenting with dry eyes. Although the evaporative loss of tears can cause reflex hypersecretion, many patients with dry eyes will have an inflammatory component. Therefore, besides the use of artificial tears and ointments, patients may need to have the inflammation controlled. Many of these patients will not have a tear volume deficiency but will demonstrate tear film instability. Meibomianitis and associated tear film instability have been found to be the main cause of tearing in as many as 20% of patients presenting with chronic epiphora.
Epiphora in Facial Palsy
There are multiple causes of tearing in a patient with facial nerve dysfunction. If the tearing is worse when the patient chews, laughs, talks, or opens the mouth, then the cause is aberrant nerve regeneration: the facial nerve branches that would normally go to the parotid gland regenerate to supply the lacrimal gland. The tearing is sometimes called "crocodile tears" (or Bogorad syndrome). This hyperlacrimation usually develops six months or more after the development of facial palsy. Although the reference to crocodiles crying when they eat their prey is thought to be more than a thousand years old, the first written documentation is found in "The voyage and travel of Sir John Mandeville" published in 1400: the book quotes "in that country be a general plenty of crocodiles. These serpents slay men, and they eat them weeping." In mythology, it was thought that crocodiles wept tears while eating their prey to show sorrow. Physiologically, it is thought that the tearing occurs in crocodiles because of the pressure caused by the eating, which in turn forces air into the sinuses. This increase in forced air into the sinuses is thought to stimulate the lacrimal glands. Another explanation is that crocodiles are noisy eaters with huffing and other noises, and this, in turn, causes the lacrimal glands to be stimulated.
Until recently, patients were offered various surgical procedures, including partial resection of the lacrimal gland, sphenopalatine ganglion block with alcohol, surgical denervation of the lacrimal gland, or vidian neurectomy. Vidian neurectomy gave a 50% success. The other procedures were unreliable and ran the risk of creating excessive dryness. Currently, injection of 2.5 to 4 units of botulinum toxin-A into the lacrimal gland gives relief for three to four months. Botulinum toxin-A inhibits acetylcholine release and normally acts at the neuromuscular junction. In the lacrimal gland, the toxin stops transmission in the abnormal parasympathetic nerves.
In facial palsy, the orbicularis pump may be weakened with or without a frank lower eyelid laxity or ectropion and retraction. By examining the patient while they attempt tight closure, one can grade the orbicularis weakness (normal, mild, moderate, severe weakness). This is performed by attempting to open the squeezed eyelids. Most patients with facial nerve dysfunction will have some degree of orbicularis weakness and lower eyelid laxity with a frank retraction and/or ectropion. Inspection should show the lower eyelid sitting at the inferior limbus. Lower eyelid laxity examination is carried out with the distraction test and the snap-back test. Finally, many of these patients will have a sensory cause of tearing as well because of corneal exposure secondary to lagophthalmos. Bell phenomenon should always be assessed, and the degree of lagophthalmos documented. In our experience, epiphora in patients with facial weakness is almost always multifactorial. Simply tightening the lower eyelid may improve the lagophthalmos but rarely improves tearing unless the orbicularis weakness is only mild. Puntal eversion is also common because of the weakness of the orbicularis muscle. In many patients, the only way to substantially improve tearing is to insert a Lester Jones tube with a conjunctivodacryocystorhinostomy (CDCR). When we place a Lester Jones tube, we always tighten the lower eyelid at the same time to improve tear flow, even if the pump is not improved much.
Tests performed in patients presenting with epiphora are classified as secretory tests and excretory tests and discussed in the chapter "Epiphora: clinical testing." The tests performed include the following:
Appropriate management of epiphora depends on the etiology. For example, treatment of surface irritation with lubrication or eyelid repositioning surgery can decrease reflex tearing. Punctoplasty is performed to widen a tight punctum. Typically one tip of a pair of scissors is introduced into the punctum to snip the punctum, creating a wider orifice. Balloon dacryoplasty (balloon dilation) introduces a balloon into the nasolacrimal system, which is inflated and then deflated and removed to push open the obstruction. The dacryocystorhinostomy (DCR) surgical procedure creates a passage from the nasolacrimal sac to the middle meatus in the nose. The conjunctivodacryocystorhinostomy (CDCR) surgical procedure creates a passage from the conjunctiva to the middle meatus. The goal of both procedures is to create passages for tear drainage that bypass obstructions; the appropriate procedure is chosen based on the location of the obstruction. In patients for whom surgery is not an ideal option, such as some patients with malignant NLDO, injection of botulinum toxin into the lacrimal duct can provide relief.
With a high rate of spontaneous resolution, “watchful waiting” is appropriate for many cases of pediatric epiphora. For congenital NLDO that does not resolve, probing with consideration of balloon dilation and/or silicone tube placement should be the first intervention. If the NLDO persists, DCR or CDCR can be performed.
The causes of adult epiphora may be summarized anatomically as follows:
Epiphora in Children
Numerous conditions in children may cause epiphora:
Epiphora is treatable in most patients with the appropriate diagnosis and treatment. A few patients are left with tearing without any underlying cause, and these are sometimes said to have "functional epiphora." Various treatments, including intubation, dacryocystorhinostomy, and injection of the lacrimal gland with botulinum toxin, have been used for patients with functional epiphora with varying success.
Complications of specific procedures performed for the management of epiphora are discussed under each procedure.
Patients should be instructed not to rub their eyes, which can stretch the periocular tissues and worsen surface irritation. Education on proper technique for lubricating the ocular surface is also important for many patients.
Patients with tearing will present to opticians, optometrists, ophthalmologists, and family physicians. It is important for each group to be aware of the different causes of epiphora so that appropriate tests may be requested by referring patients to the appropriate specialist. [Level 4]
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