Eye Cancers: An Overview
What Is Eye Cancer?
Eye cancer is the growth of malignant cells in the tissues of the eye. In adults, most eye cancers are secondary tumors that spread to the eye from other parts of the body (often the breast, although cancers of the lungs, kidneys, and prostate gland are sometimes involved). These cancers spread via the bloodstream or the lymphatic system.
Two primary tumors arise within the eyes: retinoblastomas and melanomas. Among children, retinoblastoma is the most common primary eye cancer; it generally affects children under age five. Malignant melanoma of the eye is found most frequently in adults (the average age at diagnosis is 60 to 65 years old). Most primary eye cancers affect only one eye, but retinoblastoma involves both eyes in about one-third of cases. According to the American Cancer Society, about 2,580 new cancers of the eye and orbit occur each year in the United States.
Symptoms may not be evident in the early stages of any form of eye cancer; growing tumors may increasingly cause pain and impair vision, however. Cancers that originate in the eye may spread (metastasize) outside the eye (the globe) to the optic nerve, the brain, or the rest of the body, so early diagnosis and treatment are important. Treatment for eye cancer is aimed at destroying cancerous cells, relieving symptoms, and preserving sight as much as possible. Treatment for secondary eye tumors also involves treating the primary cancer elsewhere in the body.
What Causes Eye Cancer?
- It is unknown why primary eye melanomas arise.
- Exposure to ultraviolet (UV) rays (either from the sun or tanning beds) increases the risk for melanoma.
- The most common cause of metastatic eye cancer in adults is the spread of a tumor from another site in the body.
- Genetic factors play a role in retinoblastoma.
Symptoms of Eye Cancer
- Gradual distortion, loss of vision, or loss of visual field in the affected eye
- Pain and redness in the affected eye
- Swelling and watering of the eye
- Different color irises in each eye
- Floaters or light flashes in the field of vision
- In retinoblastoma, an eye may turn in or out (crossed eyes). Later, visible whiteness in the pupil may be seen
- Melanomas often produce no symptoms. A black or brown spot on the iris or the white of the eye can develop
- Bulging eyes (with a secondary tumor located behind the eyeball)
Eye Cancer Prevention
- If retinoblastoma runs in your family, genetic counseling is advised for family planning.
- Newborns and children in families with a history of retinoblastoma should have regular dilated eye examinations with an ophthalmologist.
Eye Cancer Diagnosis
- An ophthalmologist will conduct a complete eye examination, possibly requiring general anesthesia in young children.
- An ultrasound examination and sometimes CT (computed tomography) scans of the head and eye may be performed. Ultrasound is the more useful and common test.
- Ancillary tests such as lumbar puncture and blood studies may be necessary.
- Tests to diagnose melanomas include ophthalmoscopy (color fundus photography), fluorescein angiography, biopsy and MRI (magnetic resonance imaging) scan.
How Eye Cancer Is Treated
- Laser surgery or cryosurgery (freezing the targeted tissue with liquid nitrogen) may be used to destroy small tumors.
- Radiation therapy may be used to kill cancerous cells, in conjunction with or in lieu of surgery.
- Chemotherapy may be used to halt or limit the spread of the cancer. Recently, new chemotherapeutic agents have been successful in treating retinoblastoma within the eye.
- Surgical removal of the eye may be necessary to prevent the cancer from spreading, or when an eye is completely blind and painful.
When to Call a Doctor
Make an appointment with an ophthalmologist if you develop any of the symptoms of eye cancer.