Lacerations of the canalicular system often occur in the setting of trauma.[1, 2] The canaliculi are the mucosal ducts through which tears drain from the eye.[3] 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).[4] 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.[1]
Lacerations of the canalicular system result from direct or indirect trauma.[5, 6] 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.[6]
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.
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.[7] Lacerations to the canalicular system account for a very small percentage of these facial lacerations
International
A 2-year study of patients with eyelid injuries in Munich, Germany, found that 16% of eyelid lacerations involved the canalicular system.[8] A similar study in India showed that the canaliculus was involved in 24 (36%) of all eyelid lacerations. A 2006 survey of United Kingdom ophthalmologists showed that management of canalicular lacerations varies widely in the United Kingdom.[9] Eighty-three percent of the 92 UK 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.[10, 11]
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.
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.
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 eMedicineHealth's Eye and Vision Center. Also, see eMedicineHealth's patient education articles Eye Injuries and Black Eye.
The mechanism of injury must be elicited during the history.[6] 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.
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 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. Sixty-six percent of all patients with a dog bite – related injury had involvement of the canaliculi in a 10-year study of patients presenting to the Massachusetts Eye and Ear Infirmary.[12]
The photographs below show a patient with a canalicular injury from a dog bite and postoperative result.
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Toddler who sustained a dog bite injury with isolated canalicular laceration of the left lower lid.
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Postoperative (1.5 y after injury) appearance of toddler who sustained a dog bite injury with isolated canalicular laceration of the left lower lid. T....
The photographs below show a canalicular injury sustained from a fingernail and postoperative result.
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Canalicular system intubated with 6-0 Prolene suture prior to passing a segment of Crawford stent in a patient who sustained superior canalicular lace....
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Postoperative appearance of a patient who sustained superior canalicular laceration from a fingernail injury while playing basketball.
Canalicular laceration incurred during a motor vehicle accident is shown in the photographs below.
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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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Postoperative appearance of the patient in the photo above who sustained canalicular laceration following a motor vehicle accident.
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.
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.
Injection of air, water, or various solutions (eg, fluorescein) has been recommended in locating the medial aspect of the canaliculus. When only one canaliculus is lacerated, a pigtail probe is useful in locating the medial aspect of the lacerated canaliculus and guiding insertion of the silicone lacrimal stents. The use of magnification by either surgical loupes or the operating microscope usually allows for visualization of the white cuff of the severed canaliculus.
Alcaine or tetracaine can be used to anesthetize the eye. Once any form of open globe injury has been ruled out, the wound should be immediately irrigated with water or saline. One or two drops of povidone-iodine ophthalmic solution 0.5 % can be used to sterilize the ocular mucosa.
Tetanus prophylaxis must be confirmed in any contaminated injury. Rabies prophylaxis with both active and passive immunization may be necessary in certain canine bites; in most domestic dog bites, it is not necessary. The usual workup should be performed for a human bite (see Human Bites).
Postoperatively, most surgeons prescribe a broad-spectrum antibiotic, such as cephalexin or amoxicillin clavulanic acid. Some surgeons do not routinely use systemic antibiotics.[13] Considerations for using antibiotics should include the risk factors for infection. Patients at increased risk for infection include patients taking immunosuppressant medications or steroids and patients with diabetes, rheumatoid arthritis, alcoholism, cirrhosis, asplenia, or any other systemic condition that affects the immune system. Additional factors that increase the risk for infection include the extent and depth of the wounds.
The US Department of Health and Human Services 2013 guidelines recommend antibiotic treatment for facial cat and dog bites.[14] Wound care includes topical ophthalmic antibiotic ointment 4 times per day and ophthalmic antibiotic solution 4 times per day.
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 as soon as possible because of the significant contamination present in the wound.[15]
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. Laser guidance has been suggested as another alternative.[16] Recently, a modified pigtail probe, which combines both the rounded cannula and an irrigation port, has been designed to facilitate both identification and repair of the lacerated canalicular system.[17]
A study of 63 patients with traumatic canalicular lacerations reported higher success rates in patients treated with direct canalicular wall sutures compared with pericanicular sutures.[18] The modified rounded-eyed pigtail probe method of canalicular repair has been reported to have a 97.4% success rate in re-establishing the severed system.[10] 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.[19, 20] Intubation of the injured lacrimal system has been shown in an animal model to facilitate successful repair.[21] 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.[22, 23]
Both the monocanalicular and bicanalicular approaches yield excellent outcomes.[24, 10] Care should be taken with repair of the lacrimal system, as unusual complications of passing the metal intubation probe have been reported.[25]
The pericanalicular tissue can be opposed with 7-0 Polyglactin 910 suture.[26] 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.
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.
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.
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.
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.
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.
Isolated canalicular trauma can be treated on an outpatient basis.
In those patients in whom inpatient care is needed, medications may 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.
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.
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.
Clinical Context:
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.
Clinical Context:
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.
Christian El-Hadad, MD, CM, FRCSC, Fellow, Orbital Oncology, Ophthalmic Plastic and Reconstructive Surgery, University of Texas MD Anderson Cancer Center
Disclosure: Nothing to disclose.
Coauthor(s)
Jean Deschênes, MD, FRCSC, Professor, Research Associate, Director, Uveitis Program, Department of Ophthalmology, McGill University Faculty of Medicine; Senior Ophthalmologist, Clinical Director, Department of Ophthalmology, Royal Victoria Hospital, Canada
Disclosure: Nothing to disclose.
Specialty Editors
Francisco Talavera, PharmD, PhD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference
Disclosure: Received salary from Medscape for employment. for: Medscape.
Chief Editor
Hampton Roy, Sr, MD, Associate Clinical Professor, Department of Ophthalmology, University of Arkansas for Medical Sciences
Disclosure: Nothing to disclose.
Additional Contributors
Louise A Mawn, MD, Associate Professor, Departments of Ophthalmology and Neurological Surgery, Director of Oculoplastic and Reconstructive Service, Vanderbilt University School of Medicine
Disclosure: Nothing to disclose.
Stephen D Plager, MD,
Disclosure: Nothing to disclose.
References
Hawes M, Dortzbach R. Trauma of the lacrimal drainage system. Linberg J, ed. Lacrimal Surgery. New York: Churchill Livingstone; 1988. 241-262.
[Guideline] US Department of Health and Human Services. Management of cat and dog bites. Available at http://. http://guideline.gov/content.aspx?id=46428. Accessed: September 19, 2014.
Gonnering R. Periorbital animal bites. Linberg J, ed. Oculoplastic and Orbital Emergencies. Prentice Hall; 1990. 215-228.
Toddler who sustained a dog bite injury with isolated canalicular laceration of the left lower lid.
Postoperative (1.5 y after injury) appearance of toddler who sustained a dog bite injury with isolated canalicular laceration of the left lower lid. This photo demonstrates normal anatomy and function of the eyelid.
Canalicular system intubated with 6-0 Prolene suture prior to passing a segment of Crawford stent in a patient who sustained superior canalicular laceration from a fingernail injury while playing basketball.
Postoperative appearance of a patient who sustained superior canalicular laceration from a fingernail injury while playing basketball.
Canalicular laceration in the setting of a more extensive medial canthal injury in a woman involved in a motor vehicle accident.
Postoperative appearance of the patient in the photo above who sustained canalicular laceration following a motor vehicle accident.
Toddler who sustained a dog bite injury with isolated canalicular laceration of the left lower lid.
Postoperative (1.5 y after injury) appearance of toddler who sustained a dog bite injury with isolated canalicular laceration of the left lower lid. This photo demonstrates normal anatomy and function of the eyelid.
Canalicular system intubated with 6-0 Prolene suture prior to passing a segment of Crawford stent in a patient who sustained superior canalicular laceration from a fingernail injury while playing basketball.
Postoperative appearance of a patient who sustained superior canalicular laceration from a fingernail injury while playing basketball.
Canalicular laceration in the setting of a more extensive medial canthal injury in a woman involved in a motor vehicle accident.
Postoperative appearance of the patient in the photo above who sustained canalicular laceration following a motor vehicle accident.
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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