Eye cancer

Retinoblastoma

• Pupil of the eye appears white instead of red when light shines into it. This may be seen in flash photographs of the child.
• Eyes appear to be looking in different directions.
• Pain or redness in the eye.

Intraocular melanoma may not cause any early symptoms.  It is sometimes found during a routine eye exam when the doctor dilates the pupil and looks into the eye. The following symptoms may be caused by intraocular melanoma or by other conditions. A doctor should be consulted if any of these problems occur:

• A dark spot on the iris.
• Blurred vision.
• A change in the shape of the pupil.
• A change in vision.

Sources: National Cancer Institute and UC Davis Comprehensive Cancer Center 

Retinoblastoma is a relatively uncommon tumor of childhood that arises in the retina and accounts for about 3% of the cancers occurring in children younger than 15 years. There are tumors that occur in heritable (40%) and non-heritable (60%) forms. Heritable disease is the only known cause.

Risk factors for intraocular melanoma include:

• Older age
• Being white
• Having a fair complexion (light skin) or green or blue eyes
• Being able to tan

Sources: National Cancer Institute and UC Davis Comprehensive Cancer Center 

Standard treatment for retinoblastoma

• Enucleation

Enucleation is surgery to remove the eye and part of the optic nerve.  The eye will be checked with a microscope to see if there are any signs that the cancer is likely to spread to other parts of the body. This is done if the tumor is large and there or no chance that vision can be saved. The patient will be fitted for an artificial eye after this surgery. Close follow-up is needed for 2 years or more to check for recurrence in the area around the eye.

• Radiation therapy

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, plaques, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated. Methods of radiation therapy used to treat retinoblastoma include the following:

• Intensity-modulated radiation therapy (IMRT)

A type of 3-dimensional (3-D) radiation therapy that uses a computer to make pictures of the size and shape of the tumor. Thin beams of radiation of different intensities (strengths) are aimed at the tumor from many angles. This type of radiation therapy causes less damage to healthy tissue near the tumor.

• Stereotactic radiation therapy

Radiation therapy that uses a rigid head frame attached to the skull to aim high-dose radiation beams directly at the tumors, causing less damage to nearby healthy tissue. It is also called stereotactic external-beam radiation and stereotaxic radiation therapy.

• Proton beam radiation therapy

Radiation therapy that uses protons made by a special machine. A proton is a type of high-energy radiation that is different from an x-ray.

• Plaque radiotherapy

Radioactive seeds are attached to one side of a disk, called a plaque, and placed directly on the outside wall of the eye near the tumor. The side of the plaque with the seeds on it faces the eyeball, aiming radiation at the tumor. The plaque helps protect other nearby tissue from the radiation.

• Cryotherapy

Cryotherapy is a treatment that uses an instrument to freeze and destroy abnormal tissue, such as carcinoma in situ. This type of treatment is also called cryosurgery.

• Photocoagulation

Photocoagulation is a procedure that uses laser light to destroy blood vessels to the tumor, causing the tumor cells to die. Photocoagulation may be used to treat small tumors. This is also called light coagulation.

• Thermotherapy

Thermotherapy is the use of heat to destroy cancer cells. Thermotherapy may be given using a laser beam aimed through the dilated pupil or onto the outside of the eyeball, or using ultrasound, microwaves, or infrared radiation (light that cannot be seen but can be felt as heat).

• Chemotherapy

Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column, an organ (such as the eye), or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated.

Treatment of ocular melanoma

• Radiation Therapy

Radiation therapy is the most common treatment for eye melanoma since the patient does not require removal of the eye. Studies have shown no difference in patient survival regardless of whether the melanoma is treated with radiation or eye removal surgery.

• Surgery

The surgical option for treatment eye melanoma is eye removal (enucleation). This is the simplest and most definitive treatment for eye melanoma, but this is reserved usually for patients with poor vision and large tumors. If the tumor has extended outside the eyeball into the surrounding tissue, removal of the surrounding tissues in the eye socket also will be performed (exenteration). Surgery is also an option for small melanomas involving the iris.

• Surveillance

Continued surveillance for signs of extraocular metastasis of ocular melanoma is needed even with successful eye treatment since patients are at risk for metastasis. This can be done by a medical oncologist or ocular oncologist.

More about surgical interventions for eye cancer

Sources: National Cancer Institute and UC Davis Comprehensive Cancer Center