Proptosis in Cats

Dislocation of an eyeball from its socket is an alarming and serious event. In cats, it is almost always associated with some form of head injury. In brachycephalic (push nose) breeds, the severity of injury required to cause proptosis is much lower than in other domestic house cats because their eye sockets are shallower.

Proptosis is uncommon in cats. Cats whose eyelids are trapped behind their eyeball, or whose eyeball is completely out of the socket require emergency veterinary care.

Brachycephalic (aka “push-face” or short-nosed) breeds have shallow eye sockets and therefore are at much greater risk for proptosis than other cats.

The severity of proptosis depends on how much damage has been done to the eyeball itself, how much damage there is to the structures that usually keep the eyeball in place, and how long it takes for treatment to begin.

In mild cases, the eyeball pops out just enough to trap the eyelids behind it, but no further damage to the eyeball or the surrounding structures occurs.

In more severe cases, associated issues include:

• Rupture of the eyeball
• Damage to the the muscles that hold the eyeball in place
• Fractures in the skull or eye socket
• Lacerations of the skin

Typically, both mild and severe proptosis are associated with swelling around the eye, bleeding around or within the eye, misalignment of the eyes, and pain.

The cause of proptosis is traumatic injury to the head. In cats with flat faces, even a minor head trauma has the potential to pop the eyeballs out of their place. In these breeds, even mild trauma from restraining the cat may be sufficient to cause proptosis. For other cats, it takes severe trauma to cause this type of injury, and it is possible that other head injuries have been incurred at the same time. Possible causes of the type of injury that results in proptosis include:

• Bite injuries from a dog or other animal
• Blunt force trauma such as being hit by a car

The margins of the eyelids disappear behind the eyeball. In some cases, the eyeball pops completely out of the socket and is hanging loose on the cheek.

Typically, the characteristic symptom of a bulging or displaced eyeball is readily evident on physical and ophthalmic examination. CT scan and X-rays are used to help identify any other injuries resulting from the trauma that caused the proptosis.

Treatment begins with lubrication of the eyeball with tear-mimicking ointments. Once the cat has been put under anesthetic, the eyeball is put back in its normal position. The eyelid is then temporarily sewn shut to keep the eyeball in place while the tissues heal.

Further treatment includes:

• Antibiotics to prevent infection
• Anti-inflammatories to reduce inflammation
• Pain medication
• Restricting activity
• Wearing an elizabethan collar to prevent scratching

In 5 to 7 days, further assessment of the eyeball is made, to determine the eye’s health and whether additional treatments are required.

In the case that the eyeball is too severely damaged to return to function, an enucleation (the removal of the eyeball) is necessary. Cats live quite comfortably without one eyeball. Cats missing both eyeballs often live comfortably once they have acclimatized to their new circumstances.

The prognosis for cats with proptosis is good in cases where the eyeball has not sustained severe damage. Usually vision is maintained in these cases. In some cases, the eyes remain misaligned, or mobility of the affected eye is limited.

In cases where the eyeball is severely damaged, the prognosis for maintaining full vision is poor. Long term complications include blindness, decreased tear production, and increased likelihood of eye diseases such as ulcerative keratitis (inflammation of the cornea) and phthisis bulbi (the death of the eyeball leading to its removal).

Prevention centers around avoiding head trauma. Cats kept indoors and away from animals that may harm them are less likely to experience the types of trauma that cause proptosis.

In brachycephalic breeds, proptosis is possibly prevented by a partial tarsorrhaphy, a surgical procedure where the corners of the eyelids are sutured so that the opening between the eyelids is smaller. This helps to hold the eyeball in its place.

Proptosis is rare in cats. It is more common in brachycephalic breeds.

• Replacement of the eyeball back in place
• Suturing the eyelids shut
• Antibiotics
• Anti Inflammatories
• Pain medication
• Surgical removal of eyeball