Ocular Melanoma (Eye Melanoma), from the CureRays guide library.

Ocular melanoma is a rare cancer inside the eye; precise radiation, often a small implant placed on the eye, controls most tumors while preserving the eye itself.

What it is.

Ocular melanoma, also called uveal melanoma, is a rare cancer that begins in the pigment-making cells inside the eye — the same kind of cells that can cause melanoma of the skin, but here they are in the eye's middle layer (the uvea), which includes the colored iris, the ring of muscle behind it (the ciliary body), and the lining behind the retina (the choroid). It is the most common cancer that starts inside the adult eye. Because it grows out of sight, it often causes no early symptoms and may be found during a routine eye exam; when symptoms do occur, they can include blurred vision, flashes or floaters, a growing dark spot on the iris, or a change in the shape of the pupil. Unlike skin melanoma, ocular melanoma is not caused by sun exposure and is diagnosed mainly by an eye specialist's examination and imaging rather than a biopsy. The central goals of treatment are to control the tumor, preserve the eye and as much vision as possible, and reduce the chance of spread — and radiation is the leading way to do this.

How radiation treats it.

Radiation uses focused high-energy beams to damage the DNA inside tumor cells so they can no longer grow and divide. In ocular melanoma, radiation is the leading treatment because it can control the tumor while preserving the eye — something surgery to remove the eye cannot do. The most common method, plaque brachytherapy, places a small radioactive disc directly on the outside of the eye over the tumor for a few days, concentrating the dose precisely where it's needed. For tumors in delicate locations, an external proton beam can deliver a sharply focused dose from outside the eye while protecting the optic nerve and central vision. Treatments are designed to maximize tumor control while sparing sight. Side effects depend on the tumor's size and location and can include changes in vision over time, dry eye, or cataract, which the eye team monitors and manages. For most patients, radiation controls the tumor and saves the eye.

The ways we can treat it.

Plaque brachytherapy. A custom radioactive plaque is placed directly on the eye over the tumor for several days, then removed, giving a concentrated dose to the cancer while limiting exposure to the rest of the eye.

Proton beam therapy. An external proton beam delivers a sharply focused dose that stops right at the tumor, useful for tumors near the optic nerve or fovea where preserving vision is critical.

Stereotactic radiosurgery. Highly focused external radiation in one or a few sessions is another eye-preserving option for selected tumors when plaque or proton treatment isn't ideal.

Questions we hear often.

Is ocular melanoma caused by sun exposure? Unlike melanoma of the skin, ocular melanoma is not clearly linked to sun exposure. It arises from pigment cells deep inside the eye, and its exact causes are still being studied, though certain eye colors and genetic factors may raise the risk.

Will I lose my eye? Usually not. Most ocular melanomas are treated with eye-preserving radiation — often a small radioactive plaque placed on the eye — that controls the tumor while keeping the eye. Removing the eye is reserved for very large tumors or when the eye can't be saved.

Where does ocular melanoma spread if it spreads? When it spreads, ocular melanoma most often goes to the liver. Because of this, doctors monitor the liver with imaging over time. New immune-based treatments designed for this cancer have, for the first time, been shown to help patients whose disease has spread.

This guide is informational only. It is not medical advice — please confirm anything here with your care team.