Corneal Puncture/Laceration

 

A tale as old as time.  Dog sees cat. Dog chases cat. Cat wins.

This little pup is a 12-week-old English Bulldog who was so excited to be welcomed into his new home only to be whacked promptly right in the face with the family cat’s danger mittens. 

The owner noted acute onset of squinting and watery discharge and then the pup seemed almost as good as new and was going back for more.  On presentation this is what the eye looked like, what do you see?

There is moderate corneal edema in the central cornea with a focal penetrating injury plugged with fibrin. There is moderate chemosis and conjunctival hyperemia. 

What are your concerns now?  What is the prognosis and how can you tell?

Some things you should be thinking about are when the injury occurred, if the puncture/laceration is sealed, and if any intraocular structures are involved. Let’s work through those questions.

When did this occur?  Why does that matter? 

Well, if the puncture/laceration happened 5 days ago the risk of infection at the site of the trauma and inside the eye is much higher and therefore the prognosis is a bit more guarded.  Infection inside the eye is called endophthalmitis and it is BAD news.  Eyes often cannot come back from infection inside the eye.  If the eye isn’t in terrible shape, aggressive treatment will be recommended but the prognosis and risk of persistent infection should certainly be discussed with the owners and taken into consideration.

Is the puncture sealed?  How can you tell?

If the puncture is sealed it is typically sealed with fibrin or iris/uveal tissue.  Fibrin looks like snot.  It can be clear, tan, brown, or black and looks like an eye booger stuck at the puncture site.  Be careful to not pull this out or debride it because you will open the hole and that can be a bit shocking when the eye deflates! If you see something that looks like that and you can’t rinse it away, don’t touch it! 

You can tell if a puncture is sealed by doing something called a Seidel test.  A Seidel test is basically a leak test.  This is performed by flooding the surface of the tear film with fluorescein and then watching closely with your cobalt blue light to see if the fluorescein over the suspected perforation site is being diluted by a stream of aqueous humor.  If you see fluid diluting your fluorescein, then you have a leak.  If there is communication still with the outside world, surgical closure of the site will be needed and there is risk of bacteria from the ocular surface entering the eye.

Is the lens damaged? Why does this matter?

Rupture of the lens can cause a massive inflammatory response in the eye.  The lens capsule typically keeps the lens material safely protected enclosed within the capsule and therefore the inside of the eye is not used to the lens protein.  Rupture causes a sudden exposure of lens protein to the inside of the eye which results in essentially a foreign body reaction inside the eye.  This is called phacoclastic uveitis, sometimes called phacoanaphylaxis.  This often causes severe uveitis and synechia and subsequent secondary glaucoma.

Trauma to the lens also causes cataract formation.  If by lucky chance the lens contact does not cause severe blinding uveitis, vision limiting cataract may develop.  Some cataracts are punctate and focal and do not limit vision.  Some are blinding and cataract surgery may be an option to restore vision depending on other changes that may have occurred because of the trauma.

Treatment:

How do you treat this?

• Topical antibiotic drops.  Do not use ointment because petrolatum can be quite irritating if it gets into the eye.  I recommend something like a fluoroquinolone that can penetrate the cornea.  Good options are Ofloxacin and Ciprofloxacin.
• Systemic antibiotics.  I like Clavamox due to its broad-spectrum antimicrobial coverage.  Because of the uveitis it should be able to get adequate concentrations in the eye and hopefully help treat/prevent endophthalmitis.
• Systemic anti-inflammatories.  The uveitis should be controlled with systemic NSAIDs if possible.
• E-collar.  These eyes are often delicately sealed, if sealed at all, and self-trauma should be avoided.
• Referral.  If the lens has been contacted or if you can’t tell, referral is ideal.  If the laceration is greater than 0.5mm long (essentially more than just a puncture), surgical repair should be considered.  If the eye is Seidel + (leaking) then referral for surgery is ideal.
• Surgical repair involves direct closure with simple interrupted sutures (8-0 typically). 
  

What if referral is not possible?

If you have a sealed puncture AND the lens is not involved, you can try to medically manage.  If there is a small leak and the lens is not ruptured, you may be able to treat with a bandage contact lens or a third eyelid flap combined with medical management.  If the lens is ruptured and severe uveitis is present, enucleation is probably the best option for comfort.

 

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About the Guide: Kristin Miller Fischer, DVM, DACVO