A laceration over the nasolacrimal canal is visible in Dr Leonid Skorin's photograph of a young girl who was bitten around the eye by a dog. An ophthalmologist needs to be consulted whenever a laceration occurs in this area. Failure to repair the nasolacrimal canal properly can result in permanent tearing and discomfort.
A laceration over the nasolacrimal canal is visible in Dr Leonid Skorin's photograph (Figure) of a young girl who was bitten around the eye by a dog (CONSULTANT, September 1, 2005, page 1106). The portion of the canal potentially affected by this wound carries excess lacrimation from both the superior and inferior puncta. An ophthalmologist needs to be consulted whenever a laceration occurs in this area. Failure to repair the nasolacrimal canal properly can result in permanent tearing and discomfort.
-John Benecki, PA
Your concern about possible damage to a portion of this child's nasolacrimal drainage system is justified. In most persons, about 70% of tears drain through the lower canaliculus and the remainder through the upper canaliculus.1 However, in some persons, the upper canaliculus is responsible for removing most of the tears.2 Unfortunately, in most clinical settings--especially in an emergent situation--determining whether the upper or lower system is predominant in tear excretion is not possible. Also, although a single canaliculus (particularly the lower) may be sufficient for drainage of basal tear secretion, both canaliculi are required to provide satisfactory tear drainage during increased tear secretion that may occur on a reflex basis.3 Thus, if either canaliculus is lacerated, it should be repaired.
Even very small eyelid lacerations may involve the canalicular system. A high index of suspicion is important when evaluating the medial eyelids. Medial conjunctival lacerations often involve the canalicular system; therefore, examination of the canalicular system with a Bowman probe should be done under topical anesthesia to help localize possible damage.4
An ophthalmologist should be consulted when canalicular damage is suspected. The best opportunity for successful repair of a canalicular laceration is at the time of the injury.5 However, the laceration can be safely repaired up to 48 to 72 hours after the injury--or even longer in select cases.3 This gives the primary care provider time to repair any other injuries and make an appropriate referral. Delaying surgery may allow time for any significant edema to diminish, which further facilitates the repair.5
In the case of this 9-year-old girl, I performed a physical examination with both irrigation and gentle probing and found the nasolacrimal system to be intact. If I had detected a canalicular laceration, I would have repaired it by intubating the canaliculus with a stent and closing the laceration in layers to minimize any undue tension, paying strict attention to anatomic alignment.
Since I am an ophthalmologist, I feel comfortable performing this type of surgery. Canalicular lacerations should be repaired by ophthalmic surgeons, otorhinolaryngologists, or plastic surgeons because specific techniques and instrumentation are required.
-Leonid Skorin, Jr, DO
Albert Lea Eye Clinic
Mayo Health System
Albert Lea, Minn
1. Kanski JJ. Clinical Ophthalmology. 4th ed. Boston: Butterworth-Heinemann; 2000:44.
2. White WL, Glover AT, Buckner A, et al. Relative canalicular tear flow as assessed by dacryoscintigraphy. Ophthalmology. 1989;96:167-169.
3. Gossman MD. Management of eyelid trauma. Focal Points: Clinical Modules for Ophthalmologists. Vol 14, No 10. San Francisco: American Academy of Ophthalmology; 1996:1-14.
4. Long LA, Tann TM. Eyelid and lacrimal trauma. In: Kuhn F, Pieramici DJ, eds. Ocular Trauma: Principles and Practice. New York: Thieme; 2002:373-382.
5. Murphy BA, Klippenstein KA, Wesley RE. Trauma to the lacrimal system. In: Mauriello JA, ed. Unfavorable Results of Eyelid and Lacrimal Surgery: Prevention and Management. Boston: Butterworth-Heinemann; 2000:477-490.