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Ophthalmology > LACRIMAL SYSTEM
Laceration, Canalicular
Article Last Updated: Aug 4, 2006
AUTHOR AND EDITOR INFORMATION
Section 1 of 11  
Author: Louise A Mawn, MD, Assistant Professor, Department of Ophthalmology, Vanderbilt University School of Medicine
Louise A Mawn is a member of the following medical societies: American Academy of Ophthalmology, American College of Surgeons, American Medical Association, American Society of Ophthalmic Plastic and Reconstructive Surgery, Association for Research in Vision and Ophthalmology, and North American Neuro-Ophthalmology Society
Editors: Stephen D Plager, MD, FACS, Chief, Department of Ophthalmology, Dominican Hospital; Assistant Clinical Professor, Department of Ophthalmology, Stanford University Hospital; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Mark T Duffy, MD, PhD, Consulting Staff, Division of Oculoplastic, Orbito-facial, Lacrimal, and Reconstructive Surgery, Green Bay Eye Clinic, BayCare Clinic; Lance L Brown, OD, MD, Ophthalmologist, Affiliated With Freeman Hospital and St John's Hospital, Regional Eye Center, Joplin, Missouri; Hampton Roy Sr, MD, Associate Clinical Professor, Department of Ophthalmology, University of Arkansas for Medical Sciences
Author and Editor Disclosure
Synonyms and related keywords:
canalicular laceration, canalicular system, canaliculi, tear drainage system, lacrimal drainage apparatus, lacrimal system, lacrimal sac, nasolacrimal duct, mucosal ducts, tear ducts
Background
Lacerations of the canalicular system often occur in the setting of trauma. The canaliculi are the mucosal ducts through which tears drain from the eye. The canalicular portion of the tear drainage system is in the medial aspect of the lid. The lacrimal drainage apparatus consists of the puncta on the upper lid and the lower lid, the canaliculi, the common canaliculus, the lacrimal sac, and the nasolacrimal duct.
Each eyelid margin can be divided into the larger palpebral portion (consisting of skin, orbicularis muscle, insertion of lid retractors, tarsal plate, and conjunctiva) and the smaller lacrimal portion (consisting of skin, orbicularis, canaliculi, and conjunctiva). The palpebral potion of the lid is lined with lashes; posterior to the lashes are the openings of the meibomian glands of the tarsal plate. The palpebral margin assumes a flat contour. The lacrimal portion of the lid is round and without lashes. Injuries to the canalicular portion of the tear drainage system can occur as isolated injuries or as one component of more extensive injuries, including multiple marginal lid lacerations, orbital fractures, and globe injuries.
Pathophysiology
Lacerations of the canalicular system result from direct or indirect trauma. Direct trauma includes severing the lacrimal portion of the lid with objects, such as glass, coat hangers, knives, dog bites, cat claws, fingernails, or other sharp objects. Indirect trauma results from blunt injury to the ocular adnexa from such mechanisms as blows to the face, blunt weapons, or falls onto blunt objects.
Because of its superficial location in the medial lid, the canalicular system is vulnerable to trauma. The anatomy of the system includes the 2-mm vertical portion, which drains the puncta, and the 8-mm horizontal limb, which lies in the lacrimal portion of the lid, approximately 2 mm from the lid margin. The medial extent of the canaliculus interrupts the posterior arm of the medial canthal ligament. This ligament often is disrupted from the trauma and must be repaired to reestablish anatomic position and lid function.
Frequency
United States
Canalicular lacerations are the most frequent cause of injury to the lacrimal system. The inferior canaliculus is involved in more than 50-75% of cases. The horizontal lower limb is the most frequently involved site. In 2002, there were approximately 1.97 million visits to emergency departments for facial lacerations. Lacerations to the canalicular system account for a very small percentage of these facial lacerations. A survey of surgeons in the United Kingdom found that 83% of 92 surgeons repaired fewer than 5-10 canalicular lacerations per year.
Mortality/Morbidity
If the canalicular system is not repaired initially, tearing can result from the disruption of the lacrimal anatomy, and the medial canthal area can have an abnormal appearance. Studies have demonstrated that both the inferior and the superior lacrimal drainage system can be instrumental in proper function of the tear drainage system. Primary repair can restore both lid function and position. Once the microscopic lacrimal system is scarred, it cannot be functionally repaired.
Race
Race has not been reported to be a factor in trauma to the canalicular system.
Sex
Males are more frequently the victims of trauma to the lacrimal system than females.
Age
Canalicular lacerations are most common in young adults. Canalicular lacerations in toddlers frequently result from dog bites. The mean age range is reportedly 18-30 years.
History
The mechanism of injury must be elicited during the history. Delineating the mechanism of injury helps to establish the extent of injury, the possibility of associated ocular damage, the degree of contamination, and the risk for retained foreign bodies.
- Objects projecting from the wound may indicate intracranial injury. Until imaging studies are obtained, projecting objects should not be extracted.
- Ground soil contamination may raise the need to cover for Bacillus cereus.
- Dog bite injuries need immediate decontamination.
- Documentation of the cause of injury, including whether the accident was work related, can be important medicolegal information.
Physical
In the setting of acute trauma, attention to life-threatening and then visual-threatening injuries, particularly an open globe, must take precedence over examination or repair of any adnexal injury.
- A complete ophthalmic examination must be performed, including visual acuity, pupil reaction (with specific mention of whether a relative afferent pupillary defect is present), visual fields, extraocular movements, intraocular pressure, external examination, slit lamp examination, and dilated examination of the optic nerves and posterior pole. Injuries of the lacrimal system can occur in the setting of major head trauma, in which case, dilation of the pupils may not be permissible from a neurologic standpoint.
- Any lid laceration medial to the pupil should be considered to involve the canalicular system until proven otherwise. To check for disruption of the system, the puncta can be dilated, followed by insertion of a Bowman probe. Another method of confirming a canalicular laceration includes irrigating substances, such as fluorescein stained balanced saline solution, through the system with visualization of the dye in the wound.
- Examination of the orbit for any associated injuries (eg, orbital fractures) must be performed. Fractures of the maxillary bone in the area of the nasolacrimal duct can cause difficulty in silicone intubation through the nasolacrimal duct.
Causes
Causes of canalicular lacerations include assaults, falls and collisions, sharp trauma (eg, knives, coat hangers, fingernails, glass), motor vehicle accidents, dog bites, cat scratches, and sports trauma.
Nasolacrimal Duct, Obstruction
Other Problems to be Considered
Full-thickness lid laceration not involving the lacrimal drainage system
Partial-thickness lid laceration
Epiphora
Periocular contusion
Periocular ecchymosis
Lab Studies
- Laboratory studies only include those needed by emergency trauma care providers. The lacrimal system laceration does not require laboratory studies.
Imaging Studies
- In any patient with suspected orbital or midface fractures, orbital computed tomography should be obtained in the axial and coronal planes as fine cuts 2 mm apart. If an optic canal fracture is suspected, the ophthalmologist must ensure that the images are obtained with negative angulation to ensure that the optic canals are well visualized.
Other Tests
- Although not used in the acute setting, dacryocystogram can confirm a disruption of the lacrimal drainage system.
Procedures
- Injection of air, water, or various solutions (eg, fluorescein) has been recommended in locating the medial aspect of the canaliculus. The use of magnification by either surgical loupes or the operating microscope usually allows for visualization of the white cuff of the severed canaliculus.
Medical Care
Tetanus prophylaxis must be confirmed in any contaminated injury. Rabies prophylaxis with both active and passive immunization may be necessary in certain carnivore bites; in most domestic dog bites, it is not necessary. Postoperatively, most surgeons prescribe a broad-spectrum antibiotic, such as cephalexin, for the patient. Wound care includes topical ophthalmic antibiotic ointment 4 times per day and ophthalmic antibiotic solution 4 times per day.
Surgical Care
Acute microscopic repair with either an operating microscope or surgical loupes is required to reanastomose the severed ends of the canaliculi. In most injuries, this repair can be accomplished within 48 hours of the trauma. Successful repairs have been reported within 5 days of the injury. Animal bites should be addressed immediately because of the significant contamination present in the wound.
Repairs on children are best performed under general anesthesia. For most adults, repairs can be performed with monitored anesthesia with intravenous sedation or if an isolated laceration even local anesthesia. In those patients with extensive ocular adnexal trauma or more extensive injuries, general anesthesia may be the preferred anesthetic approach. Local hemostasis and anesthesia are augmented with nasal vasoconstrictors, such as 4% cocaine or phenylephrine soaked cottonoids, and a local injection of 2% lidocaine with 1:100,000 epinephrine (in adults) or 0.5% lidocaine with 1:200,000 epinephrine (in children) to the area of the lacrimal sac and in both the superior and the inferior medial eyelid.
Familiarity with the anatomy of the medial canthal area is essential for accurate repair of the canalicular system. Because of the difficulty in finding the severed ends if one is not experienced with these injuries, a wide variety of methods, such as instilling various fluids (eg, saline, boiled milk, antibiotic solutions, methylene blue, sodium hyaluronate, fluorescein), have been suggested. Most recently, laser guidance has been suggested as another alternative. Regardless of the method used to determine the location of the severed ends, they must be anastomosed to recover functional patency.
The puncta must be dilated, and a Bowman probe must be passed delicately through the canaliculus. The severed end of the canaliculus is a shiny white cuff of tissue at the edge of the lumen. Most surgeons favor silicone intubations of the system, with repair of the pericanalicular injury. Intubation of the injured lacrimal system has been shown in an animal model to facilitate successful repair. Intubation can be accomplished with either bicanalicular intubation (either by passing the stent ends through the nasolacrimal duct or by using a modified eyed pigtail probe) or monocanalicular intubation. The pericanalicular tissue can be opposed with 7-0 Polyglactin 910 suture. In addition, the medial canthal tendon must be repaired in its anatomic location, posterior to the lacrimal sac at the posterior lacrimal crest. If the disrupted tendon is not repaired, both the appearance and the function of the lid will be abnormal.
Consultations
Consultation and treatment by an oculoplastic surgeon, who is experienced with the repair of lacrimal injuries, is recommended. Ophthalmic plastic and reconstructive surgeons are trained first in eye diseases and surgery; additional expertise then is obtained in the anatomy of the ocular adnexa. Injuries to the lacrimal drainage system can be quite complex and involve not only the tear drainage system but also the lid anatomy, including the medial canthal tendon. Associated injuries can include full-thickness lid lacerations or orbital fractures.
Diet
As soon as patients with isolated canalicular trauma recover from anesthesia, they may resume their preoperative diet. Trauma surgeons entrusted with systemic care manage patients with multiple injuries.
Activity
Normal activity can be resumed following surgery. If orbital fractures have occurred, the patient is asked not to blow the nose because it can cause orbital emphysema. High-pressure activities that require Valsalva maneuvers should be avoided because they can lead to ecchymosis in the lid area or even orbital hemorrhage.
The medications used in treating canalicular lacerations are antibiotics that help to prevent infection. Intraoperatively, the wounds are decontaminated with copious irrigation of antibiotic solution. Postoperatively, topical antibiotic ointment is applied to the skin wound, topical antibiotic solution is instilled to treat the lacrimal system, and system antibiotics are used if wound contamination is possible. An ophthalmic antibiotic steroid often is used for topical use since it also decreases inflammation.
Drug Category: Antibiotics
Used in prevention of postoperative inflammation and scarring of the lacrimal drainage system.
| Drug Name | Tobramycin and dexamethasone (TobraDex) |
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| Description | Indicated for infections of the eye. Tobramycin interferes with bacterial protein synthesis by binding to 30S and 50S ribosomal subunits, which results in a defective bacterial cell membrane. Dexamethasone decreases inflammation by suppressing migration of polymorphonuclear leukocytes and reducing capillary permeability. |
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| Adult Dose | Apply to affected eye qid |
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| Pediatric Dose | Administer as in adults |
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| Contraindications | Documented hypersensitivity; active bacterial, viral, or fungal infection |
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| Interactions | None reported |
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| Pregnancy | B - Usually safe but benefits must outweigh the risks.
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| Precautions | Must rule out the possibility of corneal fungal infections; suspect fungal invasion in any persistent corneal ulceration where a corticosteroid has been used or is in use (obtain fungal cultures when appropriate); prolonged use may increase hazard of secondary ocular infection |
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| Drug Name | Cephalexin (Keflex, Biocef, Keftab) |
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| Description | Indicated for infections. First-generation cephalosporin arrests bacterial growth by inhibiting bacterial cell wall synthesis. Bactericidal activity against rapidly growing organisms. Primary activity against skin flora; used for skin infections or prophylaxis in minor procedures. |
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| Adult Dose | 250-1000 mg PO q6h for 10-14 d; not to exceed 4 g/d |
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| Pediatric Dose | 25-50 mg/kg/d PO divided q6h; not to exceed 3 g/d |
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| Contraindications | Documented hypersensitivity |
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| Interactions | Coadministration with aminoglycosides increases nephrotoxic potential |
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| Pregnancy | B - Usually safe but benefits must outweigh the risks.
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| Precautions | Adjust dose in severe renal insufficiency (high doses may cause CNS toxicity); superinfections and promotion of nonsusceptible organisms may occur with prolonged use or repeated therapy |
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Further Inpatient Care
- Inpatient care typically is directed by the trauma service admitting the patient.
Further Outpatient Care
- Children with trauma to the eyelids must be monitored closely to ensure that deprivational amblyopia does not occur from eyelid ptosis.
- Patients with traumatic ptosis typically are observed for 6 months before proceeding with repair; exceptions include complete ptosis in a child at risk for amblyopia. The silicone stent is removed 3 months to 1 year after the repair depending on the extent of the trauma.
In/Out Patient Meds
- Isolated canalicular trauma can be treated on an outpatient basis.
- In those patients in whom inpatient care is needed, medications include intravenous Ancef (1 g q8h in adult for first 24 h).
- If the patient is able to take oral antibiotics, then a broad-spectrum antibiotic, such as (Keflex 500 mg qid), can be used for 10 days. A broad-spectrum ophthalmic antibiotic ointment, such as TobraDex, is used 4 times per day to the wounds for the first 2 weeks. An ophthalmic antibiotic solution, such as TobraDex, is used 4 times per day to the lacrimal system for the first 2 weeks.
- Patients who are immunosuppressed or who have undergone prior splenectomy are at risk for developing infection with dysgonic fermenter-2 24-48 hours after a dog bite.
Transfer
- Patients with extensive injuries often are transferred to a rehabilitation facility. Postoperative care must include assessing the wound for infection, patency of the lacrimal system, and stent position.
Deterrence/Prevention
- Canalicular injuries resulting from sports injuries could potentially be avoided with proper headgear.
- Those lacerations resulting from assault often are alcohol abuse related.
- Close surveillance of toddler interactions with the family pet or a known dog may be helpful in preventing a significant number of canalicular lacerations in toddlers.
Complications
- Premature loss of the stent can occur with bicanalicular repair with passage of the stent through the nasolacrimal duct. The stent can prolapse through the puncta, raising concern of the patient and family members. When the eyed pigtail probe method is used, the knot can rotate and cause conjunctival irritation. The puncta can erode from any of the stent materials used to repair the laceration. Pyogenic granulomas may form adjacent to the stent. Nasal irritation or nosebleeds may occur from stents passed through the nose. Despite acute repair, chronic epiphora may develop. The medial lids may become webbed because of opposed lacerations.
Prognosis
- The success rate with canalicular repair ranges from 20-100%. The success rate rises to 86-95% with microscopic reanastomosis of the severed canaliculus with silicone intubation of the lacrimal system.
Patient Education
- Attention to the anatomy of the lacrimal drainage system and the medial aspect of the lid is critical for those ophthalmologists and emergency physicians who are assessing these injuries. Suspicion must be raised in any laceration of the medial eyelid.
- The balance between tear production and outflow must be explained to patients. In addition, limitations secondary to the extent or nature of the trauma must be discussed with the patient.
- For excellent patient education resources, visit eMedicine's Eye and Vision Center. Also, see eMedicine's patient education articles Eye Injuries and Black Eye.
Medical/Legal Pitfalls
- Patients who are not offered primary repair may experience epiphora or cosmetic disfigurement. The examining or treating physician may be called upon to offer testimony as to the nature and extent of the trauma. Detailed documentation can be instrumental in this process.
| Media file 1:
Toddler who sustained a dog bite injury with isolated canalicular laceration of the left lower lid. |
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| Media file 2:
Postoperative (1.5 y after injury) appearance of same patient as in Image 1 demonstrating normal anatomy and function of the eyelid. |
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| Media file 3:
Canalicular system intubated with 6-0 Prolene suture prior to passing a segment of Crawford stent. |
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| Media file 4:
Postoperative appearance of a man (same patient as in Image 3) who sustained superior canalicular laceration from a fingernail injury while playing basketball. |
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| Media file 5:
Canalicular laceration in the setting of a more extensive medial canthal injury in a woman involved in a motor vehicle accident. |
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| Media file 6:
Postoperative appearance of same patient as in Image 5 who sustained canalicular laceration following a motor vehicle accident. |
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| Media file 7:
Woman with tearing and medial canthal asymmetry after the repair of a laceration sustained during a domestic assault. An emergency room physician performed the repair. |
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- Conlon MR, Smith KD, Cadera W. An animal model studying reconstruction techniques and histopathological changes in repair of canalicular lacerations. Can J Ophthalmol. Feb 1994;29(1):3-8. [Medline].
- Gonnering R. Periorbital animal bites. In: Linberg J, ed. Oculoplastic and Orbital Emergencies. Prentice Hall;1990:215-228.
- Hawes M, Dortzbach R. Trauma of the lacrimal drainage system. In: Linberg J, ed. Lacrimal Surgery. New York: Churchill Livingstone;1988:241-262.
- Hawes MJ, Segrest DR. Effectiveness of bicanalicular silicone intubation in the repair of canalicular lacerations. Ophthal Plast Reconstr Surg. 1985;1(3):185-90. [Medline].
- Ho T, Lee V. National survey on the management of lacrimal canalicular injury in the United Kingdom. Clin Experiment Ophthalmol. Jan-Feb 2006;34(1):39-43. [Medline].
- Jordan DR, Nerad JA, Tse DT. The pigtail probe, revisited. Ophthalmology. Apr 1990;97(4):512-9. [Medline].
- Kersten RC, Kulwin DR. "One-stitch" canalicular repair. A simplified approach for repair of canalicular laceration. Ophthalmology. May 1996;103(5):785-9. [Medline].
- Liang T, Zhao KX, Zhang LY. A clinical application of laser direction in anastomosis for inferior canalicular laceration. Chin J Traumatol. Feb 2006;9(1):34-7. [Medline].
- Linberg J. Surgical anatomy of the lacrimal system. In: Linberg J, ed. Lacrimal Surgery. New York: Churchill Livingstone;1988:1-18.
- Reifler DM. Management of canalicular laceration. Surv Ophthalmol. Sep-Oct 1991;36(2):113-32. [Medline].
- Saunders DH, Shannon GM, Flanagan JC. The effectiveness of the pigtail probe method of repairing canalicular lacerations. Ophthalmic Surg. Jun 1978;9(3):33-40. [Medline].
- Wulc AE, Arterberry JF. The pathogenesis of canalicular laceration. Ophthalmology. Aug 1991;98(8):1243-9. [Medline].
Laceration, Canalicular excerpt Article Last Updated: Aug 4, 2006
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