Eye Cancer: Frequently Asked Questions
Q: How does the eye work?
A: The eye is an organ that collects light and sends it to the brain. The brain turns the light from the eye into pictures that allow people to see. The eye is made up of many different parts.
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The eyelids keep the eyes moist and shield them from light. The conjunctiva is a very thin membrane that covers the eyeball and lines the eyelids. It lets the eyelid blink easily without irritating the eye. The cornea covers and protects the iris, which is the colored part of the eye, and its main function is to focus light. The ciliary body is muscle tissue that has two functions. One is to make the aqueous fluid. The other is to help focus the eye. The retina lines the inside of the eye and sends information from the eye to the brain, doing the work that helps people to see.
The retina has a layer of blood vessels under it called the choroid. The choroid feeds the retina. The choroid, iris, and ciliary body make up the uvea and contain cells called melanocytes. Other parts of the eye can also have melanocytes. These cells can sometimes grow into a type of cancer called melanoma.
Q: What is cancer of the eye?
A: Eye cancer is a very rare kind of cancer that starts in or on the eye (on the surface, on the iris, or within the eye beneath the retina). It can also start in the skin around the eye (the eyelid). Because it is so rare, it is best for a person diagnosed with eye cancer to seek treatment from someone who specializes in this field. A person can ask his or her healthcare provider to refer him or her to an eye cancer specialist.
Q: What are the different types of eye cancer?
A: There are different kinds of eye cancers. Below are some of the places near or on the eye where cancers can grow and the types of cancers that may be present on each of these places:
Eyelid tumors. Basal cell carcinoma, a kind of skin cancer, is the most common type of eyelid cancer. Other types of eyelid tumors include squamous cell carcinoma, sebaceous cell carcinoma, and malignant melanoma.
Conjunctival tumors. Tumors that grow on the surface of the eye.
Iris tumors. Tumors that grow in the colored part of the eye.
Choroid tumors. Tumors that grow in the layer of blood vessels that support the retina. They include melanoma of the choroid, which is a malignant tumor, as well as choroidal nevus and choroidal osteoma, which are benign tumors.
Intraocular lymphomas. This cancer usually begins in the eyeball. It is typically non-Hodgkin lymphoma.
Lacrimal gland tumors. Tumors that are found in the gland that makes tears.
Retinoblastoma. This is a cancer of the eye that affects children. It is extremely rare in adults. It will not be discussed in this section.
Q: How is cancer of the eyelid treated?
A: The treatment most commonly used for cancer of the eyelid is surgery. The goal of surgery is to remove all of the cancer. The type of surgery used depends on the size of the tumor. If the tumor needs removal of most of the eyelid, the eyelid will be remade using plastic surgery. In some cases, radiation may be needed after surgery to kill any cancer cells that may have been left behind.
Q: How are conjunctival tumors treated?
A: The primary treatment for these tumors is surgery. It is important for the healthcare provider to keep checking for cancer cells that may have been left behind. The surgery ends when all cancer cells have been removed. This is called perioperative microscopic exam of surgical margins, or Mohs surgery.
If the tumor is large, cryotherapy (freezing of the tumor) may be needed. Researchers are also studying the use of chemotherapy eye drops for people who have conjunctival cancers.
Q: How are tumors in the iris treated?
A: These are rare tumors. Treatment of these tumors depends on whether the tumor is growing and also whether there is any complication from the tumor (for example, uncontrolled glaucoma). In the case of glaucoma that does not get better with medicine, or if the tumor is growing quickly, it may be necessary to remove the entire eye. If the tumor is not growing and the glaucoma can be controlled with medicine, treatment may be surgical removal of part of the iris (iridectomy) or radiation therapy.
Q: How are choroidal tumors and tumors of the ciliary body treated?
Melanomas. The treatment for choroidal melanomas can include thermal destruction (cryotherapy or photocoagulation), radiation, surgery to remove the tumor, complete removal of the eye, or no treatment at all (observation alone). The choice depends on the size of the tumor, on whether or not it is growing, and whether or not the person is having symptoms. All these choices should be discussed in depth with the healthcare provider, weighing all the risks and benefits of each choice.
Nevus. Nevi in the eye can be compared to freckles on the skin. They almost never need treatment. Nevi can turn into melanoma. If they do, they are treated as melanoma.
Q: How are intraocular lymphomas treated?
A. The treatment for intraocular lymphoma is chemotherapy or radiation, or a combination of both. Surgery is not used for this type of eye cancer.
Q: What are clinical trials?
A: Clinical trials are studies of new kinds of cancer treatments. Healthcare providers conduct clinical trials to learn how well new treatments work and what their side effects are. If they look promising, they are then compared to the current treatment to see if they work better or have fewer side effects. People who participate in these studies may benefit from access to new treatments before the FDA approves them. Participants also help further our understanding of cancer and help future cancer patients.
Q: Should everyone get a second opinion?
A: Many people with cancer get a second opinion from another healthcare provider. There are many reasons to get a second opinion, including if the person is not comfortable with the treatment decision, if the type of cancer is rare, if there are different ways to treat the cancer, or if the person is not able to see a cancer expert.
Q: How can someone get a second opinion?
A: There are many ways to get a second opinion:
The person's primary healthcare provider may be able to recommend a specialist, such as a surgeon, medical oncologist, or radiation oncologist. Sometimes these healthcare providers work together at cancer centers or programs.
The National Cancer Information Service (800-4-CANCER) informs callers about treatment facilities, including cancer centers and other programs supported by the National Cancer Institute.
Patients can get names of healthcare providers from their local medical society, a nearby hospital, a medical school, or local cancer advocacy groups, as well as from other people who have had that type of cancer.