A proptosis refers to a sudden protrusion of the globe from the orbit. While they can appear quite scary, with some preparation they can easily be addressed. The number one question that you as a practitioner need to determine, is should the globe be replaced or should an enucleation occur.
Due to this injury occurring from a multitude of different types of traumas ranging from a big dog-little dog attack to hit-by-cars, the overall pet needs to be evaluated prior to addressing the proptosis. During your stabilization period, you can treat the eye by administering systemic pain medication and applying topical lubrication. Once the pet is stable systemically, you can further evaluate the prognosis for the globe.
Indications for Replacement
Positive indicators include:
- Positive menace response (difficult to assess due to the eyelids being behind the globe)
- Positive consensual pupillary light reflex
- Fewer than 3 extraocular muscles ruptured
- Breed (brachycephalic breeds have a better prognosis than dolichocephalic breeds)
Negative indicators include:
- Complete hyphema
- A corneoscleral laceration
- Optic nerve transection
- Corneal desiccation
- Species (Dogs can be replaced; cats need to be enucleated.)
Once the decision has been made to replace the globe, prepare the patient for general anesthesia. Once anesthetized, using 3-0 or 4-0 silk, preplace 2-3 horizontal mattress sutures through stents but do not tie. Ensure that while doing this, the sutures are placed through the meibomian glands. Apply additional lubrication to the cornea and gently slide a bard-parker blade handle between the sutures and cornea. With an assistant holding the blade handle in place, lift up on all of the sutures at one time to facilitate the eyelids coming back over the globe. Tie all suture tails and prescribe a topical antibiotic and systemic pain therapy. The tarsorrhaphy should remain in place for 2-3 weeks.
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The most common complications following proptosis are:
- Corneal ulceration
- Keratoconjunctivitis sicca (KCS)
Take Home Points
The most important thing to remember is that while proptosis may be the first thing that you notice in a trauma patient, you need to ensure that the patient is stable systemically prior to addressing the proptosis. Additionally, lubrication early and often will aid you in preventing corneal ulcerations and allow you time to stabilize. Finally, if unsure if an enucleation or replacement should occur, inform the client of the risks and remember that an enucleation can always be performed at a later date, but we can never replace the globe!
- Miller, Paul E. “Ocular Emergencies.” Slatter’s Fundamentals of Veterinary Ophthalmology, 4th ed. St. Louis: Saunders (2008): 419-426.