Canalicular laceration refers to sudden penetrating injury or blunt trauma on the medial canthus (middle part of the eye where the upper and lower eyelids meet) canaliculus (canal), resulting in damage to the eye’s drainage system. Any force to this periocular area (the area surrounding the eye) is dangerous because it easily displaces the eyelid as the canalicular does not contain a tarsal substance for protection. If not well-managed, epiphora (excessive watering of the eye), ectropion (eyelid turning outward), canalicular obstruction, and poor cosmetic presentation may result. Therefore, ophthalmologists recommend immediate primary management or repair with stents (splints).
Reports indicate that canalicular injuries account for 5% of all severe eye injuries in the US, and most of these injuries tend to occur in children and teens. The home setting accounts for nearly 50% of periocular injuries, with most injuries caused by a blunt object.
Causes & Risk Factors
- Direct injury from foreign bodies like metal, glass, or organic material.
- Dog bites also cause direct injury and represent the leading cause in children's canalicular lacerations.
- Blows from fists are the most popular cause of canalicular laceration in young adults.
- Indirect injury from sources such as a fist punch to the face, finger poke on the eye, and impact from an accident or fall.
Risk factors include:
- Age, with patients under four years prone to facial dog bites and young people susceptible to trauma. Older adults are at a higher risk of falls.
- Sex, with males more affected by trauma than females. More boys than girls may suffer from facial dog bites, while more young men than women are susceptible to trauma.
- Environmental exposure to animals (e.g., the Pit Bull Terrier), objects (such as display hooks, blouse hooks, etc.), activities (certain games, fistfights, etc.) intoxicants (intoxicated persons), and others (birth trauma, surgical complication) may increase the possibility of canalicular laceration.
Signs & Symptoms
Signs and symptoms include:
- Severe epiphora
- Eye globe injuries
- Impaired tear drainage
- Lacrimal duct/sac/system injuries
The diagnosis is made through:
History of trauma on the brow, nose, or cheek
History is important because it determines the possibility of a deeper laceration, especially from glass injuries. It can also reveal if any foreign bodies were retained and whether there was wound contamination. Other historical details the doctor is looking for include a patient’s tetanus immunization history and whether s/he is allergic to drugs. The doctor will also want to know if the laceration was a result of an animal bite. A history of nasolacrimal surgery or prior ocular history is equally essential.
- Direct observation of a laceration, although the laceration may not be obvious. The doctor may use a Bowman probe, with the patient under anesthesia, to make the diagnosis. S/he may also use a viscoelastic injection.
- Physically examining the patient’s eyelid to determine canalicular trauma. Before determining canalicular laceration, the doctor first considers the patient’s overall condition. S/he must rule out life or eye-threatening injury possibilities.
- Diagnostic imaging using a CT scan and CT-orbit.
Because canalicular laceration involves an open wound, tetanus and rabies should be considered. The patient is given tetanus toxoid 0.5 mL IM if they have not been vaccinated against tetanus in the last ten years. In the case of a dog bite, the patient will receive a series of shots to prevent the virus from infecting the body and prophylaxis post-operative, to ward off infection. Augmentin is the first line of treatment for dog bites taken over 3-5 days because it’s an antibiotic that covers a broad range of organisms.
There are several surgical options available for the management of canalicular laceration. Each is selected on a case-by-case basis. Most cases are surgically repaired in the emergency department and without using general anesthesia. Children may require anesthesia, which includes ketamine. Only severe cases warrant the use of general anesthesia or intravenous sedation in a theatre. If the case is complicated, the surgeon may use an operating microscope or surgical loupes.
Earlier methods repaired the laceration using malleable rods and the pigtail probe. However, surgeons have abandoned this method because it has poor long-range effectiveness and the fact that the probe can cause damage to the uninvolved canaliculus, leading to excessive watering. This method was also limited because the surgeon could not tell before surgery whether there was a common or separate canalicular entrance to the lacrimal sac.
Another traditional method involved direct anastomosis (surgically made cross-connections) to the torn ends of the canaliculus, but the method was inadequate.
Generally, these methods are not utilized in canalicular repair today. Patients have found bicanalicular intubation intolerable since it involves retrieving the probe from the nasal cavity. Bicanalicular intubation is not required for simple canalicular lacerations.
Modern, frequently used methods include monocanalicular repair using the Mini Monoka stent that is inserted into the punctum. Another method is the bicanalicular repair that uses the Crawford Stent or Ritleng stent. These procedures have fewer side effects, risks, and complications.
Most cases of canalicular lacerations record functional and anatomic success. Functionally, the lacrimal system is restored successfully, and epiphora does not present. Rarely do patients need another surgical procedure to treat the resultant excessive watering of the eye. Complications involving eyelids folding inward or outward, ptosis, and poor eyelid position may require further surgery. However, the benefits of maintaining a functioning tear drainage system far outweigh the risk of potential complications.
Risks involving surgery include infection, vision loss (very rare), pain, scarring (if healing progresses poorly), bleeding, and the need for more procedures. Surgery presents very few complications in canalicular lacerations. The canaliculus may become obstructed if the stent material forces its way out prematurely. Other complications include nose bleeding, growth of capillary blood vessels, corneal exposure due to poor healing, ptosis (drooping of upper eyelid), and poor drainage of the nasolacrimal duct.
Prevention & Follow Up
Prevention involves avoiding situations and environments where trauma or injury can occur, such as living in a stray dog-infested area.
The first appointment should be a week after the surgical repair or as needed. In case silk sutures were used, the surgeon will remove them 10 to 14 days following surgery. The patient is advised to avoid rubbing the eye for at least two weeks after surgery.
Monocanalicular stents are removed about six weeks after the surgical intervention, while bicanalicular stents are removed after three months. The surgeon uses forceps at the slit lamp to remove monocanalicular stents, and scissors and forceps to pull out bicanalicular stents.
The patient must continue with follow up until complete healing is observed. Frequent follow-up and/or further surgery is necessary if a patient develops complications. Some surgeons recommend the use of prophylaxis postoperatively, especially in cases of bites.