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Thursday, December 23, 2010

Conjunctival Laceration

SIGNS AND SYMPTOMS
Because the conjunctiva is far less innervated than the cornea, conjunctival abrasions and lacerations are less symptomatic than corneal abrasions of the same severity. Patients will present with a history of ocular trauma and complain of mild pain or a scratchy, foreign-body sensation in the affected eye. There may be some tearing and photophobia; vision is rarely impaired. The adjacent vessels will be dilated, and there will often be a subconjunctival hemorrhage. With the slit lamp, the affected region of the conjunctiva will appear torn and the edges may be retracted, revealing the underlying sclera. Fluorescein will pool in the area of the laceration under the cobalt filter. Eventually, stain will seep underneath the conjunctiva and produce a generalized "glow" to that part of the eye. Be careful to differentiate this pattern of staining from simple accumulation of fluorescein within the physiologic folds of the conjunctiva.

PATHOPHYSIOLOGY
Although the conjunctiva is normally a tough, resilient tissue, it may be lacerated in cases of ocular trauma with sharp or pointed objects such as fingernails, tree branches or the edge of a piece of paper. In these cases, the trauma itself acts as an antigen and sets off an inflammatory cascade resulting in vasodilation and edema of the involved and surrounding tissues. Rarely is there significant white cell proliferation to the point of causing an anterior chamber reaction.

MANAGEMENT
As with any case of ocular trauma, it is important to rule out global perforation. We recommend using the Seidel test, in which you apply fluorescein to the laceration and look carefully for external leakage of aqueous. Also meticulously inspect the surrounding area to look for subconjunctival foreign bodies. Once you are certain that there are no perforations or other complications, begin treatment. If the involved area of conjunctiva is small, use a broad spectrum antibiotic (Polytrim solution Q3-4H, gentamicin solution or ointment QID, or Polysporin ointment QID) and examine the patient again in three to five days. Patching is generally not necessary for smaller lesions.

If the laceration is larger, first apply topical anesthesia and use a forceps or moistened cotton-tipped applicator to manipulate any ragged areas of conjunctiva back into position. Then instill an antibiotic ointment and pressure-patch the eye for 24 hours. While most conjunctival lacerations resolve without surgical repair, significantly large (i.e., greater than 2cm) wounds may require suturing. This should only be performed by a qualified optometrist or ophthalmologist.

CLINICAL PEARLS

Conjunctival lacerations are a minor problem that typically resolve with minimal intervention, yet patients often present with great anxiety. The fact that the eye is very red and often hemorrhaging may be cause for great concern on the patient's part, even though there is little pain or other symptoms. While it's important to rule out a penetrating injury, you can safely reassure most patients that they have a simple "cut" on their eye, and that it will heal in a few days.

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