Eye Cancer Treatments
In adults, choroidal melanoma is the most common primary intraocular cancer. It starts in the choroid, a heavily pigmented, blood vessel-rich layer underneath the retina. There are approximately 1,500 new cases of choroidal melanoma diagnosed in the U.S. each year. Melanoma can also arise in the conjunctiva or the eyelid. Very rarely, lymphoma begins inside the eyes. Primary intraocular lymphomas are almost always a type of non-Hodgkin lymphoma.
Although rare, squamous cell cancer is the most common cancer of the conjunctiva, the covering of the eyeball and inside of the eyelid. This type of cancer usually grows on the surface of the conjunctiva but can grow into and around the eye. It is generally slow growing (low grade), and very rarely spreads to another part of the body.
Standard treatments for intraocular and periocular eye cancers
Five types of standard treatment are used: surgery, active surveillance, radiation therapy, photocoagulation and thermotherapy.
Surgery and Other Procedures
Surgery is the most common treatment for intraocular melanoma. The following types of surgery may be used:
Surgery removes the tumor and a small amount of healthy tissue around it.
This involves removal of the eye and part of the optic nerve. This is done if vision cannot be saved and the tumor is large, has spread to the optic nerve or causes high pressure inside the eye. After surgery, the patient is usually fitted for an artificial eye to match the size and color of the other eye.
For more extensive disease, the surgeon removes the eye, eyelid, muscles, nerves and fat in the eye socket. After surgery, the patient may be fitted for an artificial eye to match the size and color of the other eye or a facial prosthesis.
Also called watchful waiting, this monitoring is used for patients who do not have signs or symptoms and the tumor is not growing; or the tumor is in the only eye with useful vision.
Localized plaque radiation therapy: This type of internal radiation therapy may be used for tumors of the eye. Radioactive seeds are attached to a disk, called a plaque, which is placed directly on the wall of the eye where the tumor is located. The side with the seeds faces the eyeball and delivers radiation to the eye, while the other side of the plaque helps protect nearby tissues from radiation damage.
Proton beam therapy is another option for patients with ocular cancers such as melanoma. Siteman Cancer Center operates the only proton beam therapy center in Missouri and the region. It houses the world’s first compact proton beam accelerator. Radiation oncologists and physicists here helped evaluate the system and developed the patient protocols and quality standards for this advanced technology. This treatment is ideal for patients with solid tumors that are located near sensitive structures or tissues.
This procedure uses laser light to destroy the tumor and its blood supply. It is only used to treat small tumors.
Lymphomas of the eye are often linked with lymphomas of the brain and central nervous system. Because they often spread to the brain or have already spread when the cancer is first diagnosed, both the eye and the brain are treated.
Most often, doctors treat these cancers with external radiation therapy, chemotherapy, or a combination of the two. Surgical biopsy may be needed.
Treatment may be given only to the eye, both eyes, and may include the brain and spinal cord to help prevent the lymphoma from spreading there or destroy cancer cells that may already be there.
Depending on the extent of the cancer, chemotherapy drugs may be given systemically through a vein, directly into the cerebrospinal fluid or directly into the eye, which gets higher doses of the drug to the tumor. Radiation may be given in conjunction for a stronger effect.
These may also be given directly into the eye. The best combination and dosage of drugs is determined by the cell type of lymphoma.
Squamous cell cancer of the conjunctiva
Treatment includes surgery to remove the cancer, freezing therapy (cryotherapy) and chemotherapy eye drops.