General Information About Intraocular (Eye) Melanoma
Intraocular melanoma is a disease in which malignant (cancer) cells form in the tissues of the eye.
Intraocular melanoma begins in the middle of 3 layers of the wall of the eye. The outer layer includes the white sclera (the "white of the eye") and the clear cornea at the front of the eye. The inner layer has a lining of nervetissue, called the retina, which senses light and sends images along the optic nerve to the brain.
The middle layer, where intraocular melanoma forms, is called the uvea or uveal tract, and has 3 main parts:
The iris is the colored area at the front of the eye (the "eye color"). It can be seen through the clear cornea. The pupil is in the center of the iris and it changes size to let more or less light into the eye.
The ciliary body is a ring of tissue with muscle fibers that change the size of the pupil and the shape of the lens. It is found behind the iris. Changes in the shape of the lens help the eye focus. The ciliary body also makes the clear fluid that fills the space between the cornea and the iris.
The choroid is the layer of blood vessels that bring oxygen and nutrients to the eye. Most intraocular melanomas begin in the choroid.
Anatomy of the eye, showing the outside and inside of the eye including the sclera, cornea, iris, ciliary body, choroid, retina, vitreous humor, and optic nerve. The vitreous humor is a liquid that fills the center of the eye.
Intraocular melanoma is a rare cancer, but it is the most common eye cancer in adults.
Age and sun exposure may increase the risk of developing intraocular melanoma.
Anything that increases your risk of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn't mean that you will not get cancer. People who think they may be at risk should discuss this with their doctor. Risk factors for intraocular melanoma include the following:
- Being exposed to natural sunlight or artificial sunlight (such as from tanning beds) over long periods of time.
- Having a fair complexion, which includes the following:
- Fair skin that freckles and burns easily, does not tan, or tans poorly.
- Blue or green or other light-colored eyes.
- Older age.
- Being white.
Possible signs of intraocular melanoma include a dark spot on the iris or blurred vision.
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.