A case of proptosis in cat

Traumatic Proptosis Traumatic proptosis is a forward displacement of the globe from the orbit by a traumatic episode resulting in entrapment of the eyelids behind the eye. Tarsorrhaphy is closure of the eyelids. Clinically Relevant Pathophysiology Blunt head trauma, combined with retrobulbar hemorrhage and/ or swelling and orbital fractures, can cause acute forward displacement of the globe beyond the bony orbit and eyelids. Excessive restraint of animals with large palpebral fissures and shallow orbits can also cause globe proptosis. Once displaced,contraction and inward rolling of the eyelids and spasms of the orbicularis oculi muscle prevent return of the prolapsed globe to its normal position. Ocular muscle damage, hemostasis, conjunctival swelling, and corneal exposure leading to corneal ulcers may occur. Traumatic proptosis is an emergency. In brachycephalic dog breeds, proptosis occurs easily because they have shallow orbits and large palpebral fissures that allow their globes to move forward more easily. With these dogs, less severe trauma (e.g., restraint) can cause proptosis and usually results in less tissue damage than nonbrachycephalic dogs. In dolichocephalic dog breeds and in cats, the naturally deeper orbits mean that severe trauma (e.g., vehicular accident or animal fight) is needed to cause a traumatic proptosis, and the orbital tissue damage is usually more severe. Head trauma can also cause skull, mandibular, and brain injuries. Longer eye exposure times result in more extensive corneal damage and more severe retrobulbar hemorrhage and edema. Pressure and stretching may damage the optic nerve, extraocular muscles, and orbital tissues (e.g., the lacrimal gland). Diagnosis The globe will be severely protruded, and the eyelid margins will not be visible because they are entrapped behind the eye. Subconjunctival hemorrhage, chemosis, corneal exposure, periocular bruising, and other signs of trauma are usually present. Medical Management While stabilizing the patient, immediately and frequently apply topical ointments or gels to the exposed cornea to keep it moist and minimize damage. In many cases, the animal will not allow topical treatments to be applied, but an attempt should be made. The animal should be kept without food and water, and self trauma should be prevented with a rigid E-collar. Surgical Treatment If possible, make a lateral canthus incision using a Mayo or iris scissor to enlarge the palpebral fissure enough to move the eyelids in front of the globe. Lubricate the cornea with sterile ophthalmic antibiotic ointment. Reduce entrapment of the lid margins using atraumatic forceps. Place two to four partial- thickness temporary tarsorrhaphy sutures of 4-0 nylon or silk, but do not tie them, leaving the area of the medial canthus open. Take care to allow the sutures to exit the lid margins so that sutures will not touch the cornea when tightened. Grasp the ends of the preplaced sutures with a hemostat and pull them anteriorly while applying gentle posterior pressure to the well-lubricated globe with a Jaeger lid place, smooth Bard-Parker scalpel blade handle, or the cut finger of a surgical glove. Tie the sutures with the ends left long; place stents if the sutures are excessively tight. Close the canthotomy incision with a figure-eight suture at the lateral canthus and simple interrupted sutures of 4-0 to 5-0 absorbable polyglactin 910. Place the sutures partial thickness in the eyelid to prevent corneal contact