The extent of surgery required and the surgical procedure used to excise the eyelid tumor depends on the nature of the tumor and the extent of tissue affected.
If cancer is suspected, a biopsy of tissue will be performed by fine needle aspiration or tissue biopsy. The tissue will be analyzed to determine the type of cancer present.
Tests such as radiographs, blood, and urine tests will be performed to:
- Look for indications of cancer spreading
- Rule out other conditions causing lesions of the eyelid, such as fungal and bacterial conditions
- Determine basic health of your cat prior to anesthesia being administered
- Look for signs of feline leukemia virus or feline immunodeficiency virus, which may be contributing factors to lesions on the eyelid. If these viruses are present, treatment for those conditions will need to be considered as well.
Depending on the type and extent of the tumor, either cryosurgery or traditional surgery will be performed.
Anesthesia will be required for either traditional surgery or cryosurgery on the eyelid. Your cat may be given a sedative to calm them prior to anesthesia being administered. If cryosurgery is being performed, which will be of shorter duration, intravenous anesthesia may be adequate. If a longer traditional surgery is required, intravenous anesthesia followed by the insertion of a breathing tube and maintenance of anesthesia with gas inhalation will be required.
Cryosurgery
This surgery is performed on small, contained tumors of the eyelid.
Freezing of unwanted tissue will be performed using a spray, probe, or manual application of liquid nitrogen using a swab. Another method of cryosurgery involves argon gas being used with a very thin (17 gauge) needle. The freezing usually takes about 30 seconds and if the tumor is cancerous, the tumor and surrounding tissue will be frozen to destroy it. There is no need for sutures, however the treatment may need to be repeated several times over a period of a few weeks.
Surgical Removal
Tumors that are too large or invasive for cryosurgery to be effective will be excised by traditional surgery methods.
This will involve removing the tumor and surrounding tissue with a scalpel and suturing the remaining tissue back together. Reconstructive surgery may be required, depending on the extent of tissue affected. In some cases, complete removal of the eye is necessary, when a cancerous tumor has sufficiently invaded surrounding optical tissue to warrant a more drastic procedure. In these case, the entire eye structure, including cornea, globe and optic nerve, will be removed surgically. Skin on the face and forehead will be sutured together to close the wound.
Excision of cancerous tissue may be accompanied by radiation therapy to ensure complete removal of cancerous tissue.