Proptosis is the movement of the eyeball beyond the bony socket and eyelids. As it moves forward, the eyelids become folded behind it, which prevents the eye from returning towards its normal location. The eye quickly becomes inflamed and dry; it is often bloody and may ulcerate.
Typically, only one eye is involved. Proptosis is usually caused by trauma. In dogs, it is most likely to occur in the small flat-faced breeds, because their eyes are naturally prominent. A common cause in these breeds is a dog fight, especially when a large dog grabs the small one by the scruff of the neck.
Extreme protrusion of the eyes is present. The conjunctiva is often bruised, bloody and swollen. The eye may be deviated to the outside and blood may be seen in the front of the eye. The animal is always in pain around the head and the eye is usually blind, at least temporarily. In many cases, the attachments of the eye are partially severed. Diagnosis is based on the clinical appearance of the eye. A thorough physical exam is indicated to search for injuries elsewhere and to ensure that the opposite eye is unharmed. Routine laboratories tests and chest x-rays are always recommended prior to surgery.
In most cases, proptosis is an emergency and must be treated immediately with surgery. Animals that have other serious head or internal injuries must often be stabilized for a few days before they can be safely anesthetized. If the eye is not severely damaged, surgical replacement is usually recommended. If the eye is severely damaged or surgery must be delayed for several days, then removal of the eye will be recommended. If the eye is still viable, the eyelids and suture line are monitored for excessive swelling and pain. Sutures are removed from the eyelids in 10-14 days. If the eye has been enucleated, pain medications are necessary as well as antibiotics.
Prognosis for vision is always poor. The best chance to save vision occurs in eyes that are not severely proptosed and when the animal is brought to the veterinary facility immediately and the surgery is performed within a couple of hours after the injury. Dogs with one eye can live a normal life span without any severe disabilities.
Dr. Karsten Fostvedt is a veterinarian at St. Francis Pet Clinic in Ketchum.