Diagnosis of Melanoma of the Eye

Symptoms: Patients with eye cancer may have:

• decreased ability to see
• floaters (spots or squiggles drifting in the field of vision) or flashes of light
• visual field loss (losing part of your field of sight so that instead of seeing all around, you only see part of what is around you)
• a growing dark spot on the iris
• a change in position of the eyeball within its socket
• bulging of the eye
• a change in the way the eye moves within the socket

Pain is quite rare except in cases of massive spread outside the eye. In such a case, bulging or a change in the position of the eye may be noted.

Other, less serious conditions can cause some of these symptoms. Floaters, for example, may occur as a normal part of the aging process. Regular eye exams are an important part of everyone's health care, even if there are no symptoms. If you have any of these symptoms, see a doctor promptly.

Tests for Diagnosing Melanoma of the Eye

Eye exam: Examination of the eye by an ophthalmologist (a medical doctor specializing in diseases of the eye) is the most important step in diagnosing melanoma of the eye. The doctor will look for enlarged blood vessels on the outside of the eye, which can indicate a tumor inside the eye. Using an ophthalmoscope, the ophthalmologist can get a very good look inside the eye and detect a tumor or other abnormality. Most of the time, this examination alone can make the diagnosis. To confirm the diagnosis, imaging tests such as ultrasound may be required. Very rarely will a biopsy also be needed. Even if you have been recently examined by an ophthalmologist or optometrist, if you have the symptoms listed above, get another exam. Sometimes these tumors are missed or grow so fast that they weren’t there when you were examined.

Examination of the eye and detection of tumors has been improving because of better technology. Also, the ability to take photographs of any abnormality is helpful.

Many people have a benign tumor called a choroidal nevus. These can sometimes be mistaken for eye melanomas and about 1 in 5000 will turn into melanomas. If your ophthalmologist spots one of these, the best approach is watching it to see if it grows.

Ultrasound This is another important test for helping to diagnose eye melanomas. Ultrasound is a very common test that is often used in pregnant women to look at the fetus. But it can be applied anywhere in the body. This test works by "bouncing" high frequency sound waves off the tumor and reading their pattern. It is especially useful for diagnosing eye melanomas because they have a specific appearance on ultrasound. Using this test, doctors can confirm a diagnosis of melanoma of the eye in more than 80% of cases.

Angiography: This is another technique used by ophthalmologists to help diagnose melanoma of the eye. A fluorescent dye is injected into the bloodstream through a vein in the arm. Pictures of the back of the eye are taken with light that causes the dye to fluoresce (glow). Although melanomas do not have a special appearance with this test, some other eye problems do. Doctors can use this method to tell if something is not a melanoma.

Chest x-ray: A plain x-ray of your chest will be done to see if your cancer has spread to your lungs. This is very unlikely unless your cancer is far advanced. This x-ray can be done in any outpatient setting. If the results are normal, you probably don’t have cancer in your lungs.

Computed tomography scan (CT or CAT scan): The CT scan is an x-ray procedure that produces detailed cross-sectional images of your body. It may be used to look for spread of your melanoma. Instead of taking one picture, like a conventional x-ray, a CT scanner takes many pictures as it rotates around you. A computer then combines these pictures into an image of a slice of your body (think of a loaf of sliced bread). The machine takes pictures of multiple slices of the part of your body being studied.

Often after the first set of pictures is taken, you will likely receive an intravenous (IV) injection of a radiocontrast agent, or dye, which helps better outline structures in your body. The contrast dye is injected through an IV line. A second set of pictures is then taken. Some people are allergic to the dye and get hives, a flushed feeling, or rarely, more serious reactions like trouble breathing and low blood pressure can occur. Be sure to tell your doctor if you have ever had a reaction to any contrast material used for x-rays. If you have, you may need medicine before you can have such an injection during your test.

CT scans take longer than regular x-rays, and you will need to lie still on a table while they are being done. But just like other computerized devices, they are getting faster and your stay might be pleasantly short. The newest CT scanners take only seconds to complete the study. Also, you might feel a bit confined by the ring-like equipment you’re in when the pictures are being taken.

Magnetic resonance imaging (MRI) scans: MRI scans use radio waves and strong magnets instead of x-rays. The energy from the radio waves is absorbed and then released in a pattern formed by the type of tissue and by certain diseases. A computer translates the pattern of radio waves given off by the tissues into a very detailed image of parts of the body. Not only does this produce cross-sectional slices of the body like a CT scanner, it also produces slices that are parallel with the length of your body.

A contrast material might be injected just as with CT scans but is used less often. MRI scans take longer -- often up to an hour. Also, you have to be placed inside a tube-like piece of equipment, which is confining and can upset people with a fear of enclosed spaces. The machine makes a thumping noise that you may find annoying. Some places provide headphones with music to block this out. MRI images are particularly useful in examining eye tumors. They are also helpful in detecting cancer that has spread to the brain or spinal cord, as well as any spread of the melanoma outside the eye orbit.

Biopsy: In this procedure, a small needle is passed into the eye, and cells from the tumor are sucked up into a small syringe. After processing and staining, a pathologist (a doctor who specializes in looking at tissues under a microscope) examines these cells. Although a biopsy is recommended for confirming the diagnosis of most cancers, it is usually not used for eye cancers because it is very difficult and risks damaging the eye and possibly spreading the tumor outside the eye. Because of this, and because almost all cases can be accurately diagnosed by the eye exam and imaging, most people with melanoma of the eye are treated without having a biopsy. This may change. New technology has been introduced that may make biopsy safe in situations where the diagnosis is uncertain.

Tests for Diagnosing Intraocular Lymphoma

Signs and symptoms: The first symptom of this disease is usually trouble with vision. Pain is rare. Intraocular lymphoma most often affects both eyes.

Eye exam: On examination with an ophthalmoscope, the doctor will see that the vitreous (the gel that fills most of the inside of the eye) is cloudy, and this cloudiness does not go away with treatments that would be effective for benign problems.

Imaging tests: Ultrasound is usually done to assess the nature of the mass (tumor) especially if there is no direct view of the back of the eye. MRI is often done not only to see the eye better, but also to look for lymphoma in the brain or meninges (the thin layers of tissue that surround the brain and spinal cord). CT scan is used less often as it does not provide as much detail.

Biopsy: A procedure called a vitrectomy can be done by an ophthalmologist, who takes a sample of the vitreous fluid from inside the eye with a needle-like instrument or removes a piece of tumor through a small incision. The cells in the biopsy are then examined under a microscope and by other special techniques. For more information, see the American Cancer Society document, "Non-Hodgkin Lymphoma."

Lumbar puncture: A lumbar puncture (spinal tap) is a test in which a needle is placed in the lower back to obtain a small sample of cerebrospinal fluid (fluid that surrounds and cushions the brain and spinal cord). This fluid is examined under a microscope to look for lymphoma cells, because eye lymphomas may spread to the brain.

Revised: 10/16/2006