Trastornos del sistema nasolagrimal

Demasiadas lágrimas? Podría muy bien ser causado por una obstrucción, una infección u otro problema en el sistema nasolagrimal.

By Todd Dimmick, OD, and Andrew Gurwood, OD

RELEASE DATE: APRIL 2013
EXPIRATION DATE: APRIL 1, 2016
GOAL STATEMENT:

Dacryocystocele in a neonate. A dacryocystocele is cyst-like diffuse enlargement of the lacrimal sac that tends to be painless and bluish in nature.

DECLARACIÓN DE META:

El sistema nasolagrimal es un componente vital de la homeostasis ocular. Sin embargo, si surge un problema con este sistema, está en peligro de superficie de la capa-y por lo tanto el desgarro de la salud ocular. A pesar de la importancia centrado en la superficie ocular, la importancia del sistema nasolagrimal a menudo se pasa por alto. Este curso detallado revisa los muchos posibles problemas fisiopatológicos que pueden ocurrir en el sistema lagrimal, y ofrece soluciones prácticas de gestión para hacer frente a estos trastornos.

GOAL STATEMENT:

The nasolacrimal system is a vital component of ocular homeostasis. But if a problem arises with this system, the tear layer—and therefore the health of the ocular surface—is jeopardized. Despite the importance focused on the ocular surface, the significance of the nasolacrimal system is often overlooked. This detailed course reviews the many potential pathophysiologic problems that can occur within the nasolacrimal system, and offers practical management solutions for dealing with these disorders.

FACULTY/EDITORIAL BOARD:

Todd Dimmick, OD, and Andrew Gurwood, OD

CREDIT STATEMENT:

This course is COPE approved for 2 hours of CE credit. COPE ID 37353-AS. Check with your local state licensing board to see if this counts toward your CE requirement for relicensure.

JOINT-SPONSORSHIP STATEMENT:

This continuing education course is joint-sponsored by the Pennsylvania College of Optometry.

DISCLOSURE STATEMENT:

The authors have no relationships to disclose.

The nasolacrimal system, with its many intertwined and interrelated mechanisms, is a vital component of ocular homeostasis. This important system enables the spreading, distributing and elimination of the tear constituents across the ocular surfaces (palpebra, fornix and bulbar conjunctivae and cornea). The system supports the tear layer of the eye, which is essential to ocular surface health.

But if a problem arises with the system—causing symptomatic overproduction of tearing or a lack of tears—you should perform an appropriate workup for ocular surface disease and lacrimal system obstruction. To that end, this article explains the pathophysiology and management of these disorders.

TEAR FLOW DYNAMICS

Excluding evaporation, the tear volume on the anterior surface of the eye remains relatively constant both when the eye is open and during the closing portion of the blink. On average, the eye's fornix holds 7µl of liquid when a person is in the upright position. (By comparison, the average eye drop is 20µl to 30µl).^2-6

Tear drainage occurs via the lacrimal pump mechanism.^1-7 With the start of each blink, the pars ciliaris portion of the orbicularis at the eyelid margin (the muscle of Riolan) assists lid-globe congruity and wipes tears along the corneal surface and towards the puncta via a squeegee effect.^2-6 Simultaneously, the pars lacrimalis (Horner's muscle) con tracts around the lacrimal sac, pushing tears already collected in the sac further into the system. One-third of the way through the complete blink, the puncta occlude one another.⁴As the sac is contracted, a negative pressure is created as the puncta oppose each other.^2-6

When the eye opens after a blink, tension relaxes on the lacrimal sac, the canaliculi and lacrimal sac re-expand, the puncta "pop" apart and the negative pressure created by the designed constriction draws tears back into the apparatus, refilling the lacrimal sac and canaliculi, and recycling the system.^4,5,6,7

Blockage of the lacrimal drainage system may cause tear overflow or epiphora.^5,6 Infection of the lacrimal sac gives rise to dacryocystitis.

The punctal opposition naturally prevents tear regurgitation during the event, while the valves within the system (much like valves in the venous circulatory system) prevent backflow.^2,9

Anatomy of the Nasolacrimal System

To understand the nasolacrimal system and its regulation of the tear film, we must first understand the nasolacrimal anatomy.

Each eyelid normally has one punctum situated along its margin in the region of its nasal canthus. These puncta define the beginning of the nasolacrimal apparatus. (This is the "canalicular" eyelid.) Each punctum leads into its superior and inferior canaliculus, which extends 2mm in the vertical direction to the ampulla reservoir. From the ampulla, the canaliculus turns 8mm medially toward the nasolacrimal sac.^1,2 In 90% of the population, the superior and inferior canaliculi come together to form a common canaliculus that drains into the lacrimal sac.¹ In 10% of the population, each canaliculus connects directly into the lacrimal sac.¹ The nasolacrimal apparatus continues through the 10mm lacrimal sac to exit inferiorly. Here, fluid flow is regulated by both muscular contraction and the valve of Krause.¹

The lacrimal sac becomes the 12mm nasolacrimal duct, traversing a bony duct bounded by the lacrimal and maxillary bones. Along this route is the regulatory valve of Rosenmuller.^1,3 The final 5mm of the lacrimal duct is membranous and opens into the inferior meatus, lateral to the inferior turbinate. The valve of Hasner is situated at the distal end of the duct (this valve may be imperforate in newborns, and opens spontaneously in a large percentage).^1,3 The valve of Hasner functions as a unidirectional valve that allows tears to drain out of the lacrimal system while preventing upward flow. The valve also functions to block nasal fluid entry during pressure events like coughing or sneezing.^1,3

EVALUATION

The tear film and ocular adnexal health can be evaluated without the use of instrumentation. Magnified examination of the tear film and the associated ocular tissues is accomplished using the biomicroscope or by observing the lacrimal lake with a Burton lamp. Fluorescein dye can be added to the tear meniscus and observed using cobalt blue illumination.

Overabundance of tears, lack of tears, rapid evaporation of tears, poor tear coverage over the ocular surfaces, damage to the cornea or to the conjunctiva must all be included in the differential diagnosis of symptomatic lacrimation.

The Jones test can be used to determine whether nasolacrimal apparatus obstruction is pres ent (canalicular obstruction). It is accomplished by placing 2% fluorescein into the inferior cul-de-sac of the eyelid and attempting to visualize or retrieve fluorescein from the ipsilateral nostril.¹¹ A modified Jones test describes placing granules of an artificial sweetener such as saccharin into the tear lake to see if the patient can eventually taste it, confirming at least some tear flow through the system.

Tear production deficiency can be assessed by Schirmer testing and the phenol red thread test. These tests quantify basal tear production and assist analysis of whether a patient's epiphora is secondary to poor tear movement or paradoxical tear release secondary to underlying malproduction. Normal results are 10mm to 15mm or more of tear saturation along the strip.¹¹ Poor tear volume could signal tear underproduction.

Cases of paradoxical tearing (overproduction of lacrimal fluid as stimulated by an underproduction of ocular surface lubrication) must be managed by treating the underlying cause. Poor tear production requires tear replacement therapy (artificial tears, Restasis [cyclosporine A, Allergan]) or tear drainage interruption (punctal plugs or cautery), and a medication and environmental review (systemic medications or circumstances altering tear production or efficiency). Evaporative disease can be caused by acne rosacea, which is treated with oral cycline antibiotic therapy, topical antibiotic and steroid therapy along with gland evacuation (Lipiflow, TearScience) and surface support.

Disorders of the nasolacrimal system include:

CANALICULAR OBSTRUCTION

* Pathophysiology. Unilateral epiphora (tear overflow) almost always suggests ipsilateral lacri-mal drainage system obstruction. Such obstruction can occur due to mechanical means or from processes that induce canalicular closure (stenosis).^12-14 Sources of mechanical obstruction can include debris from the lids and lashes (blepharitis, chronic conjunctivitis or makeup) and obstruction from retained punc-tal plugs that are lodged below the punctum.^12-14

Age-related constriction or scarring from adnexal trauma or from chronic infection (herpes simplex virus [HSV] or human papilloma virus [HPV]) may also render the system unpassable.^14-16 Although these etiologies are known anecdotally, a study published in 2010 proposed that HSV, HPV, makeup and sex hormones had no statistical significance on canalicular obstruction.¹⁷

* Management. Individuals who suffer from mechanical canalicular obstruction—whether it be from debris from the lids and lashes, retained punctal plugs, age-related constrictive processes (stenosis) or chronic apparatus infection—generally complain of epiphora without pain.

As the condition continues, the chemistry of the tears and the erosion of the epidermis from tear wiping may cause ulcerative fissures at the canthal areas and along the lid margins.^12-18

First aid involves cold compresses, cleaning the lids and lashes (lid scrubs), and instituting appropriate antibiotic drops and ointments to prevent infection and to moisturize the tissues.^12-17 Surgical repair is only necessary in non-remitting cases. Cases of chronic eyelid infection/inflammation (blepharitis, rosacea, psoriasis or eczema) require topical and oral antibiotics in addition to anti-inflammatory agents.

In cases when the treatment does not mitigate the problem or when there is either constrictive limitation or a punctal plug stuck in the system, irrigation and punctal dilation may be attempted.^12-17 Following dilation, irrigation of a sterile saline wash is slowly flushed through the system until it is tasted by the patient, which indicates system patency.

If the solution cannot be circulated or it consistently regurgitates from the superior punctum, this may indicate that a more significant blockage or mass is present.^11,18 If repositioning and reinjection is unsuccessful, refer the patient to an oculoplastic surgeon or one experienced in nasolacrimal system evaluation.

DACRYOCYSTITIS

* Pathophysiology. Dacryocystitis is an infection of the lacrimal sac (lacrimal sac mucocele). It can occur as result of acute or long-standing lacrimal system obstruction or from bacterial infection sourced to the contents of the tear film. Dacryocystitis may also result from the ele ments or remnants of trauma or as an extension of infective and inflammatory processes occurring within the nose or paranasal sinuses.^18-21

The mucosa that lines the lacri-mal sac and nasal lacrimal duct are inherently resistant to microbial invasion.^19-21 When a blockage occurs within the pathway, tears (laden with inflammatory material) begin to accumulate. The overabundance of inflammatory cytokines induces changes in the mucosal cellular structure.^19-21 Alterations in the ductal epithelium and the lamina propria encompassing the lacrimal sac and nasolacrimal duct allow microbial buildup, creating an environment unopposed to the seeding of infection.^19-21 The most common gram-positive organisms include Streptococcus pneumonia andStaphylococcus aureus, while Haemophilus influenza, Pseudomonas aeruginosa and Serratia marcescensare the leading the gram-negative bacteria.^19,20

Dacryocystitis with preseptal cellulitis. A painful, firm, round nodule, with adjacent preseptal eyelid cellulitis and mucopurulent discharge that can be regurgitated with palpation.

Dacryocystitis is more common in the fifth to sixth decade of life, with a mean age of 55.5 years. It can be acute or chronic in nature.^19-21 Females tend to have blockages in the nasolacrimal drainage system more often than men, with the incidence of dacryocystitis highest in postmenopausal women.^19-21 This likely occurs because the bony lacrimal duct is smaller in women than in men. Dacryocystitis is normally not seen in patients under age 30 unless there is some form of congenital nasolacrimal duct obstruction or facial trauma.¹⁸

Acute dacryocystitis often presents with symptoms of severe pain of the inner canthus in the area of the lacrimal sac just under the medial canthal ligament. Tearing, secondary conjunctivitis, mucoid discharge in the morning and an enlarged, chronically infected lacrimal sac are all clinical signs. A firm, round nodule, with adjacent cellulitis or preseptal eyelid cellulitis, is often palpable. The lacrimal sac may be "decompressable," allowing mucopurulent reflux to emerge from the puncta upon direct pressure on the sac.^18-22

* Management. Acute onset dacryocystitis is initially managed conservatively with warm compresses, massage, topical antibiotic drops, topical antibiotic ointments and a seven- to 10-day course of oral antibiotics.¹⁹ The topical antibiotics of first choice include the fourth-generation fluoroquinolones. However, data demonstrate that the organisms involved in acute dacryocystitis also respond well to gentamicin and chloramphenicol.¹⁹

The oral antibiotics of first choice include Augmentin (amoxicillin/clavulanic acid, GlaxoSmithKline), Keflex (cephalexin, Eli Lilly) and Levaquin (levofloxacin, Ortho-McNeil).¹⁹

Natural percutaneous abscess drainage is often completed through the punctum (milking the lesion) in order to relieve pain and to obtain a culture.

Dacryocystitis in children is managed more aggressively because it has a high risk of causing sepsis due to a child's immature immune system.^19,21 In these instances, admission to the hospital is common so that prompt blood culture, CT scan and IV therapy can be instituted. Treatment in admitted cases is usually accomplished using intravenous Augmentin and probing of the naso-lacrimal system.¹⁹

When conservative treatments fail, surgical solutions are needed in both acute and chronic cases.^19-22Dacryocystorhinostomy (DCR) is the gold standard for treating acute adult dacryocystitis.^19-22 DCR is defined as the resection of the bony area around the nasolacrimal canal to gain access to the stenotic area within the drainage system. The procedure permits the shunting of tear flow around any blockage by creating a new anastomotic passageway.^19-22 Interestingly, the procedure is gaining momentum as an intervention because it permits the surgeon the advantage of being able to immediately drain and culture the abscess.

New techniques of completing DCR include endocanalicular laser and endoscopic intranasal surgical techniques.¹⁹ These revolutionary methods permit the cavity to be accessed without opening the entire passage.¹⁹

The choice of the procedure depends upon the suspected etiology of the blockage and the experience of the surgeon.¹⁹ The advantage of the endoscopic procedure is good success rate for creating a nasolacrimal pathway through the bone with improved cosmesis.¹⁹

DACRYOCYSTOCELE

* Pathophysiology. Dacryocystocele is defined as a diffuse enlargement of the lacrimal sac due to a congenital nasolacrimal duct obstruction that causes the sac to fill with tears and secretions of the cells lining the sac.^22-24 The obstruction is distal to the sac and typically the result of a functional blockage in the area of the valve of Hasner.^22,23 Proximal blockages are usually due to obstructions at the level of the valve of Rosenmuller.^22,23

The distal obstruction site (valve of Hasner) commonly becomes blocked when the mesodermal lining of the apparatus does not canalize properly before birth, leaving an imperforate nasolacrimal duct.^22-24 Proximal obstruction site blockages occur when an enlarged sac creates a pressure difference, causing the common canaliculus or valve of Rosenmuller to collapse on itself.²² This creates a "ball valve" mechanism, allowing tears to flow into the apparatus without an avenue of escape.^22,23

Signs and symptoms typically include bluish, cyst-like diffuse enlargement of the lacrimal sac just underneath the medial canthal tendon.^22-24 The area of elevation tends to be painless and is absent of erythema unless a concomitant dac-ryocystitis is present.^22-24 In infants, epiphora and trouble breathing during breast feeding is commonly seen.^22-24

Dacryocystocele is most commonly seen in infants.^22-24 This condition also tends to affect females more commonly than males.²³

* Management. Conservative medical management is indicated in congenital dacryocystocle.^22,23 This includes warm compresses with gentle circulating massage, along with a short course of prophylactic topical antibiotics to prevent the formation of dacryocystitis. In many cases, the conservative approach results in recanalization of the system and complete resolution of symptoms.^22,23

Surgical intervention is required only when conservative treatment fails, respiratory function is compromised or if infection occurs.^22,23 Surgical intervention is considered immediately in most adult cases, which usually require dacryocysto-rhinostomy with or without a stent.^22,23

Surgery in congenital cases is usually accomplished with probing of the lacrimal system. In most instances, the probing alone is enough to collapse thin-walled cysts. However, when probing fails, marsupialization (widely opening the cyst, permitting drainage) prevents future blockages and infection.^22-24

CANALICULITIS

* Pathophysiology. Canaliculitis is an inflammation/infection of the canalicular aspect of the lacrimal drainage system.^25-27 Canaliculitis typically happens when a partial obstruction occurs within the canaliculi.²⁶ This leads to tear stagnation, which in turn creates an environment capable of supporting anaerobic bacterial growth.^25-27

Canaliculitis is among the most frequently missed diagnoses in ocular practice, often requiring two or more office visits to be correctly identified.^25,26 The delay in proper diagnosis is due to the combination of its rarity and the similarities of other differentials.^25,26

Canaliculitis most often occurs in postmenopausal women, with a mean age of 59 years.²⁵ It can be caused by bacteria, viruses or fungi. Signs and symptoms include ipsilateral epiphora, a swollen red lower lid and a pouting (turned outward) punctum often accompanied by mucopurulent discharge that may or may not contain yellow granules (dacryoliths).^25-27

Another distinguishing characteristic of canaliculitis is that it gives rise to recurrent conjunctivitis. Here, even when the infected cana-liculus is identified and correctly treated with appropriate topical medications, the solution is only temporary.²⁵ When the topical medication is withdrawn, infection recurs.

In canaliculitis, the presence of canalicular foreign bodies impedes the penetration of medication and makes cure unlikely unless they are removed surgically.²⁵

* Management. The medical management of canaliculitis consists of warm compresses, massage, topical antibiotics and irrigation of the nasolacrimal system with the appropriate antibiotic, antifungal or antiviral agents.^25-26

Canaliculitis with discharge and dacryolith seen in left lower lid.

Conservative treatment, to be effective, must be started within the first 30 days that symptoms become apparent. After this period, small particulate obstructions known as dacryoliths form.^25-27 These impediments block the ability of any irrigating agent from reaching the root source of blockage, making that mode of treatment ineffective.^25-27

In cases where dacryoliths are identified, dilation of the punctum along with curettage of the canaliculus can sometimes be enough> to remove the stones.^{25, 27} Dacryoliths should be cultured so that an appropriate irrigating agent can be selected. In stubborn cases, cana-liculotomy provides better access for dacryolith removal.^{25, 26}

LACRIMAL NEOPLASMS AND ENCEPHALOCELES

* Pathophysiology. Malignant or nonmalignant growths are also plausible sources of nasolacrimal obstruction.²⁸ The lacrimal system frequently remains open and patent to irrigation in benign lacrimal sac tumors, whereas complete obstruction is associated with sac carcinomas.

Seventy-two percent of lacrimal sac tumors are malignant.²⁸ Naso-pharyngeal carcinomas can involve the lacrimal sac.²⁸ Malignant epithelial tumors tend to spread along the epithelium proximally toward the eyelids and distally to the inferior nasal turbinate.²⁸ Although lacrimal sac tumors are rare, it is important to include them in the differential diagnoses of epiphora, recurrent dacryocystitis and/or lacrimal sac mass.^24,28

Encephaloceles (herniation of intracranial tissue through the embryological anatomical component known as the foramen cecum or fronticulus frontalis), nasal gliomas and dermoids (cystic tumors that arise from embryonic epidermis that has become self-encapsulated) may masquerade as lacrimal sac abnormalities or mimic the signs and symptoms of dacryocystitis.²⁹ However, these unusual entities are completely unrelated, resulting from alterations in embryologic development.^22,29 The most accepted theory of pathogenesis is that the forebrain protrudes through a faulty anterior neuropore during early lacrimal apparatus deveploment.^29,30

Of the lacrimal encephaloceles, nasal gliomas can be differentiated from dacryocystitis by their differing appearance: encephaloceles appear as soft, bluish nodules that swell upon Valsalva maneuver.^24,29-31

* Management. Neurosurgical techniques may be necessary in order to manage nasal gliomas (tumor of glial cells). Some intra-cranial lesions with nasal extension may require frontal craniotomy.²⁹

Encephaloceles, once diagnosed, are traditionally managed to prevent cosmetic deformity.²⁹

Fine-needle capillary sampling through the lower lacrimal punctum and canaliculus, with rapid cytologic testing, is required to make the diagnosis of malignancy and to facilitate early surgical intervention. Fine-needle cytology has a reported 100% concordance in differentiating benign vs. malignant orbital and eyelid lesions.⁸ In addition, the fine-needle capillary technique was found to be better than the aspiration technique in terms of smear quality, sensitivity and postsurgical discomfort induced.⁸

Multidisciplinary management is recommended in these sometimes complicated cases.⁸ Wide excision through a lateral rhinotomy results in a lower recurrence rate and is favored over the dacryocystorhinostomy approach.⁸ Pre- and/ or post-op radiotherapy has been recommended for malignant epithelial tumors.⁸Lifelong follow-up is essential.

LACRIMAL DIVERTICULUM

* Pathophysiology. The general definition of a diverticulum is an outward herniation of tissue.^8,32 A lacrimal diverticulum involves the lacrimal sac, resulting from either a developmental malformation or an abnormality produced by local trauma.^24,32 When these diverticula form, the base of their outpouchings can become inundated or occluded, producing swelling and inflammation. Back pressure can produce tearing, dacryocystocele and even dacryocystits.^24,32

* Management. There is no true medical management for lacrimal diverticula. Cases involving suspected nasolacrimal neoplasms require immediate imaging.^29-31,32 Lacrimal diverticula can be managed conservatively with warm compresses and massage but, over time, they tend to succumb to the forces of bacterial sequestration, becoming infected and requiring lacrimal drainage surgery.³²

ACUTE DACRYOCYSTIC RETENTION (LACRIMAL SAC 'STONE')

* Pathophysiology. Lacrimal sac "stones"—dacryoliths—are similar to gallstones.^33,34 Their composition and formation is poorly understood. Dacryoliths can create complete or partial nasolacrimal duct obstruction independent of the patient's age or history of acute dacryocystitis.^33,34

Cigarette smoking has been observed as a statistically significant risk factor.^33,34 Males seem to be affected more often, with dacryolith discovery being part of the initial presentation along with lacrimal sac distention.^33,34

Lacrimal stone, similar to a gallstone,
can create complete or partial nasolacrimal
duct obstruction.

* Management. The painful symptoms initially produced by lacrimal sac stones resolve in most instances without any intervention.^33,34 When intervention is required, punctal dilation with irrigation is the accepted first-line treatment strategy, provided there is no concurrent cellulitis or dacryocystitis.^33,34 If an infection is present, it must be resolved using oral and topical antibiotic therapy along with supportive hot compresses. If dilation with irrigation fails to recanalize the passage, dacryocysto-rhinostomy can be attempted.^33,34

Different Cysts and Nodules in Nasolacrimal Disorders
Dacryocystitis	Severe pain of the inner canthus just under the medial canthal ligament; mucoid discharge; secondary conjunctivitis; firm round nodule with adjacent cellulitis or preseptal eyelid cellulitis
Dacryocystocele	Painless, bluish, cyst-like diffuse enlargement underneath the medial canthal tendon; epiphora; in infants, trouble breathing when breastfeeding
Encephaloceles	Soft, bluish nodules that swell upon Valsalva maneuver
Nasal gliomas	Subdivisions of lacrimal encephaloceles
Epidermoid and dermoid cysts	Fleshy, yellow-colored cysts, firm to the touch, superior to the medial canthus along the nasofrontal suture line
Congenital lacrimal fistulae	Small orifices or pits, inferonasal to the medial canthal angle; drainage of a mucoid discharge

LACRIMAL EPIDERMOID AND DERMOID CYSTS

* Pathophysiology. Epidermoid and dermoid cysts tend to be a fleshy-yellow color and are firm to the touch.^13,15,32 They can be diagnosed based upon their appearance and are usually found superior to the medial canthus. These orbital cysts are normally found over the areas of bone sutures and are adhered to the periosteum that underlies them.

Epidermoid cysts are differentiated from the dermoid cysts by their cellular composition (underlying keratinized stratified squamous cells).³⁵

* Management. These cysts can be identified and localized with neuroimaging. Removal can be accomplished using a number of procedures, such as a superior nasal orbit incision and removal of the lesion without dissection.³⁵

CANALICULAR LACERATIONS

* Pathophysiology. Canalicular lacerations are created when an insult to the face causes a rupture of the skin along the canalicular portion of the eyelid. Lacerations can involve the upper, lower or both canaliculi.^36,37 The eyelids are more susceptible to avulsion in the area medial to the punctum.³⁶ This is because there is a lack of connective tissue (the tarsal plates are absent) in this area and because mechanical failure is at greatest risk in areas where tissues are weakest.³⁶

The pathophysiology of blunt injuries remains constant, direct and indirect impact with shear force or penetration disrupts the skin and canalicular apparatus.^36,37 Consistent with the general statistics seen with trauma, canalicular lacerations occur most often in young males around the age of 30.^36,37

* Management. Surgical intervention is indicated for canalicular lacerations. Ectropion, overflow epiphora, poor tear spread, eyelid deformity and eventually visual complications can occur if wound closure is not properly performed.³⁷ Multiple techniques of canalicular repair have been described, including bicanalicular silicone tube intubation, monocanalicular intubation (Mini Monoka, FCI Ophthalmics) and nasolacrimal duct intubation.^37,38

Generally, repair is accomplished with localization of the lacerated medial edge of the canaliculus. A stent is then threaded through the punctum and through the lateral and medial edges of the laceration, leaving an intact tube to stent the canalicular edges open while they heal.^37,38 The lacerated eyelid is then sutured over the stent with dissolvable sutures and the canalicular edges are reapproximated microscopically.³⁷

Hemolacria, or "bloody tears," occur secondary to a concomitant disease process, so the underlying cause must first be identified.

LACRIMAL FISTULA (CONGENITAL)

* Pathophysiology. Congenital lacrimal fistulae represent rare anomalies in development.⁸ The majority of fistulae originate from the common canaliculus; however, they can also arise from the lacrimal sac.⁸ The incidence of congenital lacrimal fistulae is estimated to be one in 2,000 births, and are generally inherited in an autosomal dominant fashion.⁸ Cohorts with an autosomal recessive inheritance pattern have also been reported in the literature.⁸

Lacrimal fistulae are often asymptomatic and nonprogressive, appearing as small orifices or pits that may go undetected.⁸ While most fistulae are unilateral, familial cases are associated with a higher incidence of bilateral fistulae. The location of congenital lacrimal fis-tulae is characteristically inferonasal to the medial canthal angle.⁸ Symptoms such as drainage of a mucoid discharge or epiphora may necessitate surgical excision/correction.⁸

Lacrimal fistulae share asso ciations with preauricular fistulae, hypospadias (congenital urethral displacement) and VACTERL syndrome (vertebral anomalies, anal atresia, cardiac malformations, tracheo-esophageal fistulae, renal anomalies and limb anomalies).⁸ Congenital lacrimal fistulae have been associated with thalassemia (blood cell abnormality involving altered hemoglobin chain) and Down syndrome.⁸ Associated ocular pathology includes dacryocystitis, lacrimal tract stenosis and infections of the lower eyelid.⁸

* Management. A wide range of treatment modalities for symptomatic lacrimal fistulae have been discussed in the literature.⁸ They range from nasolacrimal duct probing and cauterization of the external ostium to surgical excision of the fistula, either alone or in combination with dacryocystorhinostomy.⁸ For patients who are asymptomatic or minimally symptomatic, observation is a reasonable approach.⁸

PUNCTAL AGENESIS

* Pathophysiology. Punctal agenesis (not present/failure to develop) is associated with the absence of underlying canalicular tissue.³⁹ When one or both puncta are absent, there is a reasonable possibility that no canalicular tissue was formed.³⁹ In symptomatic cases, surgical exploration is required to determine if a maldeveloped canalicular apparatus is present and can be salvaged or if one needs to be constructed.³⁹

* Management. The treatment of choice for punctal agenesis is some form of DCR. If more than 8mm of proximal healthy canaliculus exists, standard DCR is performed and incorporates that healthy tissue.^39,40

If less than 8mm is present, then a conjunctivodacryocystorhinostomy (CDCR) is performed. The CDCR procedure differs from the DCR, as it dictates making an incision at the caruncle.⁴⁰ In CDCR, a needle is passed from the caruncle into the nasal cavity to allow for the creation of a fistula and the insertion of a bypass tube.⁴⁰ This procedure or variation creates an anastomosis from the conjunctiva to the nasal cavity to permit the maintenance of proper tear drainage, and bypasses the missing punctal opening and canalicular tissue.⁴⁰

BLOODY TEARS (HEMOLACRIA)

* Pathophysiology. Hemolacria means "bloody tears."^41,42 It is associated with conjunctival capillary hemangioma, conjunctival telangiectasias, bacterial conjunctivitis, lacrimal sac tumors, lacrimal sac infections, nasal and paranasal sinus tumors, hereditary hemorrhagic telangiectasia, Henoch-Schönlein purpura (IgA-mediated small vessel disease) and retrograde epistaxis.⁴¹ Further, hemolacria may occur in women spontaneously during the menstrual period.⁴² There have been cases of idiopathic hemolacria with no identifiable cause.^41,42

* Management. Because bloody tears occur secondary to a concomitant disease process, the underlying cause must be discovered with an appropriate workup. Idiopathic cases are a diagnosis of exclusion.^41,42

Dysfunction of the blink mechanism and its articulated wiper effect, obstruction of the puncta, obstruction or compromise of the nasolacrimal canaliculi, obstruction or infection within the nasolacrimal sac, or any formation of cystic or malignant growth can give rise to excessive, non-remitting tearing as well as collateral symptoms.

Diagnosis is facilitated by observing the tissues (conjunctivae, eyelids, cilia, surrounding glands), the blink mechanism at work, the puncta and overlying adnexa, performing tear chemistry tests, tear secretion tests, tear recovery tests, and performing dilation of the puncta with irrigation of the corresponding nasolac-rimal drainage system. Eradication of infection can be accomplished with oral, topical and intravenous antibiotics. Infections or traumas, which induce scarring and chronic system failure, require oculoplastic management. Congenital malformations and acquired diseases of the canaliculi and nasolacrimal system can be managed with system reconstruction and stenting.

Dr. Dimmick is a primary care resident at The Eye Institute of The Pennsylvania College of Optometry at Salus University, in Philadelphia. Dr. Gurwood is a professor of clinical sciences and a member of the attending staff of The Eye Institute of the Pennsylvania College of Optometry at Salus University. He is also a member of the staff at Albert Einstein Medical Center Department of Ophthalmology.

REFERENCES

1. Francisco FC, Carvalho AC, Francisco VF, et al. Evaluation of 1000 lacrimal ducts by dacryocystography. Br J Ophthalmol. 2007 Jan;91(1):43-6.
2. Oyster CW. The Eyelids and the Lacrimal System. In: Oyster CW. The Human Eye Structure and Function. Sunderland, Mass.: Sinauer Associates, Inc.; 1999:291-320.
3. Paulsen FP, Schaudig U, Thale AB. Drainage of tears: impact on the ocular surface and lacrimal system. Ocul Surf. 2003 Oct;1(4):180-91.
4. Van Santvliet L, Ludwig A. Determinants of eye drop size. Surv Ophthalmol. 2004 Mar-Apr;49(2):197-213.
5. Johnson ME, Murphy PJ. Temporal changes in the tear menisci following a blink. Exp Eye Res. 2006 Sep;83(3):517-25.
6. Sahlin, S, Chen E, Kaugesaar T, et al. Effect of eyelid botulinum toxin injection on lacrimal drainage. Am J Ophthalmol. 2000 Apr;129(4):481-6.
7. Stoeckelhuber M, Stoeckelhuber BM, Welsch U. Human glands of Moll: histochemical and ultrastructural characterization of the glands of Moll in the human eyelid. J Invest Dermatol. 2003;121(1):28-36.
8. Zhuang L, Sylvester CL, Simons JP. Bilateral congenital lacrimal fistulae: a case report and review of the literature. Laryngoscope. 2010;120 Suppl 4:S230.
9. Doane MG. Blinking and the mechanics of the lacrimal drainage system. Ophthalmology. 1981 Aug;88(8):844-51.
10. Wilson G, Merrill R. The lacrimal drainage system: pressure changes in the canaliculus. Am J Optom Physiol Opt. 1976 Feb;53(2):55-9.
11. Hagele JE, Guzek JP, Shavlik GW. Lacrimal testing: Age as a factor in Jones testing. Ophthalmology. 1994 Mar;101(3):612-7.
12. Deangelis D, Hurwitz J, Mazzulli T. The role of bacteriologic infection in the etiology of nasolacrimal duct obstruction. Can J Ophthal-mol. 2001 Apr;36(3):134-9.
13. Hidayat AA, Weatherhead RG, Al-Rajhi A, Johnson FB. Conjuncti-val and lacrimal sac pigmentation by kohl (eyeliner). Br J Ophthalmol. 1997 May;81(5):418.
14. Harley RD, Stefanyszyn MA, Apt L, Nelson LB. Herpetic canalicular obstruction. Ophthalmic Surg. 1987 May;18(5):367-70.
15. Yoshida M, Hondo R. Transmission of herpes simplex virus infection via lacrimal canaliculi. Ophthalmologica. 1992;204(2):101-2.
16. Migliori ME, Putterman AM. Recurrent conjunctival papilloma causing nasolacrimal duct obstruction. Am J Ophthalmol. 1990 Jul 15;110(1):17-22.
17. Kashkouli MB, Sadeghipour A, Kaghazkanani R, et al. Pathogenesis of primary acquired nasolacrimal duct obstruction. Orbit. 2010 Feb;29(1):11-5.
18. Jones LT. An anatomical approach to problems of the eyelids and lacrimal apparatus. Arch Ophthalmol. 1961 Jul;66:111-24.
19. Pinar-Sueiro S, Sota M, Lerchundi T, et al. Dacryocystitis: Systematic approach to diagnosis and therapy. Curr Infect Dis Rep. 2012 Jan 29;14(2):137-146.
20. Pinar-Sueiro S, Fernandez-Hermida RV, Gibelalde A, et al. Study on the effectiveness of antibiotic prophylaxis in external dacryocysto-rhinostomy: a review of 697 cases. Ophthal Plast Reconstr Surg. 2010 Nov-Dec;26(6):467-72.
21. Paulsen FP, Thale AB, Maune S, Tillmann BN. New insight into the pathophysiology of primary acquired dacryostenosis. Ophthalmology. 2001 Dec;108(12):2329-36.
22. Perry LJ, Jakobiec FA, Zakka FR, Rubin PA. Giant dacryocystomu-copycele in an adult: a review of lacrimal sac enlargments with clinical and histopathologic differential diagnoses. Surv Ophthalmol. 2012 Sep;57(5):474-85.
23. Wong RK, VanderVeen DK. Presentation and management of congenital dacryocystocele. Pediatrics. 2008 Nov;122(5):e1108-12.
24. Fussell JN, Wilson T, Pride H. Case report: Congenital dacryocys-tocele and dacryocystitis. Pediatr Dermatol. 2011 Jan-Feb;28(1):70-2.
25. Freedman JR, Markert MS, Cohen AJ. Primary and secondary lacrimal canaliculitis: a review of literature. Surv Ophthalmol. 2011 Jul-Aug;56(4):336-47.
26. Vécsei VP, Huber-Spitzy V, Arocker-Mettinger E, Steinkogler 
    FJ. Canaliculitis: difficulties in diagnosis, differential diagnosis and comparison between conservative and surgical treatment. Ophthalmo-logica. 1994;208(6):314-7.
27. Pavilack MA, Frueh BR. Through curettage in the treatment of chronic canaliculitis. Arch Ophthalmol. 1992 Feb;110(2):200-2.
28. Low JR, Bian Ng S, Sundar G. Undifferentiated carcinoma of the lacrimal sac: case report and review of literature. Orbit. 2011 Dec;30(6):293-6.
29. Rahbar R, Resto VA, Robson CD, et al. Nasal glioma and encephalocele: diagnosis and management. Laryngoscope. 2003 Dec;113(12):2069-77.
30. Patterson K, Kapur S, Chandra RS. "Nasal gliomas" and related brain heterotopias: a pathologist's perspective. Pediatr Pathol. 1986;5(3-4):353-62.
31. Puppala B, Mangurten HH, McFadden J, et al. Nasal glioma presenting as neonatal respiratory distress: definition of the tumor mass by MRI. Clin Pediatr (Phila). 1990 Jan;29(1):49-52.
32. Sinnreich Z. Lacrimal diverticula. Orbit. 1998 Sep;17(3):195-200.
33. Yazici B, Hammad AM, Meyer DR. Lacrimal sac dacryoliths: predictive factors and clinical characteristics. Ophthalmology. 2001 Jul;108(7):1308-12.
34. Gonnering RS, Bosniak SL. Recognition and management of acute noninfectious dacryocystic retention. Ophthal Plast Reconstr Surg. 1989;5(1):27-33.
35. Lelli GJ, Levy RL. Epidermoid cyst masquerading as dacryocysto-cele: case report and review. Orbit. 2011 Mar;30(2):114-5.
36. Jordan DR, Ziai S, Gilberg SM, Mawn LA. Pathogenesis of canalicular lacerations. Ophthal Plast Reconstr Surg. 2008 Sep-Oct;24(5):394-8.
37. Leibovitch I, Kakizaki H, Prabhakaran V, et al. Canalicular lacerations: repair with the Mini-Monoka monocanalicular intubation stent. Ophthalmic Surg Lasers Imaging. 2010 Jul-Aug;41(4):472-7.
38. Hussain RN, Kanani H, McMullan T. Use of Mini-Monoka stents for punctal/canalicular stenosis. Br J Ophthalmol. 2012 May;96(5):671-3.
39. Lyons CJ, Rosser PM, Welham RA. The management of punctal agenesis. Ophthalmology. 1993 Dec;100(12):1851-5.
40. Athanasiov PA, Madge S, Kakizaki H, Selva D. Diagnostic and surgical techniques: a review of bypass tubes for proximal lacrimal drainage obstruction. Surv Ophthalmol. 2011 May-Jun;56(3):252-66.
41. Ozcan KM, Ozdas T, Baran H, et al. Hemolacria: Case report. Int J Pediatr Otorhinolaryngol. 2013 Jan;77(1):137-8.
42. Praveen BK, Vincent J. Hematidrosis and hemolacria: a case report. Indian J Pediatr. 2012 Jan;79(1):109-11. 5.