Answering your Questions about Enucleation
Photo by MarVistaVet
Why Might this Procedure be Necessary?
In almost all cases, the eye is removed because it has reached a point where it has no chance of being capable of sight and it is painful. Trauma to the eye (such as an infected scratch, puncture, or hitting the eye on something sharp), tumors, glaucoma (increased pressure inside the eye), and herpes-related ulcers on the eye (in cats) are all catastrophes. Any of these conditions, or others, creates a painful, blinded eye. Brachycephalic breeds, those with flattened faces and prominent eyes, tend to be predisposed to eye injuries, and often it is these breeds that end up with one eye enucleated. The focus must become the relief of pain when restoring vision becomes hopeless.
Should Eyes Damaged Long Ago be Enucleated?
Eye damage eventually heals leaving a blinded shriveled eye. An eye in this condition is usually not painful but might be depending on tear production and chronic inflammation. If an eye has reached this stage, the veterinarian can help assess whether residual pain is enough of an issue to warrant enucleation. Most dogs do not require enucleation in this situation, but cats have a special complication for eyes in this condition: they can develop a malignant tumor in a damaged eye ("post-traumatic sarcoma). This occurs, on average, seven years from the original injury, and most tumors are highly malignant. For this reason, most collapsed eyes in the cat should be removed for cancer prevention. Post-traumatic sarcomas are the second most common primary eye tumor in the cat.
Are there any Alternatives to Enucleation?
This dog has a black ball prosthesis so as to look more natural after eye removal. Photo by Audrey Yu-Speight, DVM MS DACVO/Cornell University
Most people have a strong preference for their pets to have two eyes and would like to keep both their pet’s eyes if possible. Frequently, this is indeed possible with the help of a board-certified ophthalmologist. Many eye wounds can be trimmed and closed with proper magnification and tiny sutures. Sometimes the inner contents of the eye can be removed and replaced with a prosthesis. (This is called evisceration and the prosthesis is called a black ball.) This creates a more natural-looking eye but is not appropriate for infected eyes or eyes with tumors. There are also advanced procedures that can resolve glaucoma surgically and still spare the eye.
All of the above are highly specialized procedures that can only be performed by an ophthalmology specialist. Often enucleation is selected as the other procedures are too expensive (they often cost three or four times as much as enucleation) or enucleation may simply be the best medical choice. Enucleation can be performed by most general practitioners and referral to a specialist is unnecessary.
If you are interested in pursuing an advanced procedure, you will need a referral to a board-certified ophthalmologist. Ask your veterinarian.
Is the Surgery Painful or Disfiguring?
The Shih Tzu shown at the top of this page is a rescue named "Winky" for obvious reasons. His face shows a typical end result of enucleation. In brachycephalic breeds like Winky's, most owners let the hair grow long over the enucleated side, and the result is not at all objectionable. Pain-relieving medications are needed for the first week or so after surgery, but when healing is complete the surgical area should be pain-free and comfortable.
What can we Expect after the Surgery?
Magic Burk one eye
Magic the day after surgery. Magic is wearing an Elizabethan Collar to protect the incision.
In surgery, the eye is removed, and the eyelids are sewn closed. Sometimes there are stitches to be removed in 10 to 14 days, and sometimes the stitches are buried inside the eye socket. The eyelids will be swollen, and there may be some bruising. Some red-tinged fluid may seep from the incision, which is normal. The eye may at first look like it is simply closed. Over the first week following surgery, the swelling will go down and the socket will flatten out. An Elizabethan collar is often provided to discourage rubbing or scratching of the eye area. This collar should stay in place for 10 to 14 days until the incision is healed. The pet should be able to eat and drink with the collar in place, but if you are concerned, you may remove the collar at meal time provided the pet is well supervised.
The pet will have lost peripheral vision on the side of the enucleation and may need to adjust to being approached from this side. Cats should be kept as indoor-only pets after an enucleation as the outdoor lifestyle will pose even more hazards than usual.
One eye cat
Squirrelly the day after surgery. Note the swelling (which is normal).
What Signs Would Indicate a Problem?
Infection may pose a complication. In this event, the eye area would remain swollen after the initial week, and the incision may drain pus. If this occurs, the infection would require drainage and antibiotics. If you think there may be an infection, recheck with your vet as soon as possible. Remember, some mild oozing of red-tinged fluid is normal during the first few days after surgery.
If the eye was enucleated due to a severe tear or rupture, there may be difficulty removing the eye in one piece. Sometimes a small fragment of the rear eye membranes remains behind. If enough of this tissue is still there, secretion of fluid can continue and chronic oozing from the incision can be a problem. If this is excessive, the eye socket may require a second surgery to be fully cleaned out.
What Limitations will the Pet Have?
As long as the other eye can still see, there are not likely to be any serious handicaps. The pet will not be able to see on the enucleation side and may bump into objects. The pet may be easily startled when approached from that side. Otherwise, once healing is complete, life can return to normal. If your pet has a condition that endangers the remaining eye, be sure you understand any preventive measures that should be taken.