Uveal Melanoma

Uveal melanoma is the most common type of eye cancer in adults, yet it remains a rare disease affecting only about 5 people per million each year. Though small tumors can often be treated while preserving vision, this cancer carries a significant risk of spreading to other organs, making early detection and expert care essential.

What Is Uveal Melanoma?
Other Names
Affected Parts of the Eye
How Common Is It?
Who Is at Risk?
Signs and Symptoms
How Is It Diagnosed?
Risk of Cancer Spreading
Treatment Options

What Is Uveal Melanoma?

Uveal melanoma is a type of cancer that develops in the eye. It affects the uvea, which is the middle layer of the eye wall that contains blood vessels, cells that make pigment (called melanocytes), and structures that provide nutrients and oxygen to the retina (the part of the eye that senses light)^[1]^[4]. This cancer begins when melanocytes in the uvea grow out of control and form a tumor^[2].

Although uveal melanoma is rare, it is the most common primary eye cancer in adults^[6]^[8]. It differs from skin melanoma because it is generally not associated with sun exposure^[14].

ocular melanoma, intraocular melanoma, eye melanoma

Affected Parts of the Eye

The uvea has three main parts, and melanoma can develop in any of them^[4]^[10]:

Iris
Ciliary body
Choroid

The iris is the colored part of the eye at the front that you can see when looking in a mirror. It contains the pupil in its center, which changes size to control how much light enters the eye. Melanomas in the iris are usually small, grow slowly, and rarely spread to other parts of the body^[4].

The ciliary body is a ring of tissue located behind the iris that contains muscle fibers. These muscles change the shape of the lens to help the eye focus, and the ciliary body also makes the clear fluid that fills the space between the cornea and the iris. Melanomas in this area tend to be larger and are more likely to spread^[4].

The choroid is a layer of blood vessels that brings oxygen and nutrients to the eye. This is the most common location for uveal melanoma, accounting for about 90% of all cases^[1]^[13]. Choroidal melanomas are often larger and more likely to spread than iris melanomas^[4].

Tumors in the ciliary body account for about 6% of cases, while iris melanomas make up about 4%^[1]^[13].

How Common Is Uveal Melanoma?

Uveal melanoma is rare, affecting approximately 5 to 6 people per million each year in the United States^[6]^[8]. It accounts for only about 5% of all melanoma cases in the country^[1]^[11].

The number of new cases has remained fairly consistent over the past three decades around the world^[1]^[13]. The disease typically affects people in their 50s to 70s, with a median age of diagnosis around 55 to 60 years^[2]^[8]. Men and women are affected about equally, though some studies suggest a slight male predominance^[2]^[8].

Who Is at Risk?

Certain factors may increase a person’s chance of developing uveal melanoma, though not everyone with these risk factors will develop the disease, and some people without any known risk factors may still be diagnosed^[4]^[10].

People with fair skin that freckles and burns easily, or that does not tan or tans poorly, have a higher risk^[4]^[10]. Having blue, green, or other light-colored eyes also increases risk^[4]^[5]. The disease is most common in white people, particularly those of northern European descent, and is rare in Black, Asian, and Hispanic populations^[6]^[8].

Older age is a risk factor, and being white also increases risk^[4]^[10]. Some people may have inherited gene mutations that increase their risk, most commonly in a gene called BAP1. While most cases are not passed from parents to children, about 2 to 3% of cases involve inherited genetic mutations^[17].

Other risk factors include having certain conditions such as ocular melanocytosis (increased pigmentation in the eye), oculodermal melanocytosis, or pre-existing moles (nevi) in the eye^[6]^[8].

Signs and Symptoms

Many people with uveal melanoma have no symptoms at all in the early stages. The cancer is often discovered during a routine eye examination when a doctor dilates the pupil and looks inside the eye^[1]^[4]^[13].

When symptoms do occur, they can include^[1]^[2]^[4]^[5]:

Blurred vision or other changes in vision
Loss of vision in one eye, which may be partial or complete
A growing dark spot on the iris (the colored part of the eye)
A change in the shape or size of the pupil
Flashes of light in the vision
Floating spots in the vision (floaters) or a sensation of specks of dust
A shadow or curtain blocking part of the field of vision
Bulging of the eye
Pain or redness in the eye (less common)

It is important to know that these symptoms can also be caused by other, non-cancerous eye conditions. However, anyone experiencing changes in vision or eye health should see an eye doctor right away^[1]^[13].

How Is It Diagnosed?

Diagnosing uveal melanoma typically begins with a comprehensive eye examination. The doctor will first examine the outside of the eye and may look for enlarged blood vessels, which can be a sign of something concerning inside the eye^[15].

The doctor then uses special equipment to look inside the eye after dilating the pupil. This may include indirect ophthalmoscopy, which uses lenses and a bright light mounted on the doctor’s forehead, or slit-lamp biomicroscopy, which uses a microscope with an intense beam of light^[15].

Several imaging tests help confirm the diagnosis and show the size and location of the tumor^[14]^[15]:

Fundus photography takes color pictures of the inside surface of the eye to document the tumor
Eye ultrasound uses high-frequency sound waves to create images of the tumor and measure its size
Optical coherence tomography (OCT) provides detailed images of the eye’s structures
Fluorescein angiography or indocyanine green angiography examines the blood vessels in the tumor by injecting a colored dye into a vein and taking pictures as it flows through the eye vessels

Unlike many other cancers, a biopsy (removing a small sample of tissue to examine under a microscope) is rarely needed to diagnose uveal melanoma. Doctors can usually make the diagnosis based on the examination and imaging tests alone^[4]^[10]^[14]. However, when treatment is planned, a biopsy may be taken to test the tumor’s genetics, which helps predict the risk of the cancer spreading^[14].

Risk of Cancer Spreading

One of the most serious concerns with uveal melanoma is its risk of spreading (metastasizing) to other parts of the body. More than 50% of cases eventually spread, most commonly to the liver^[2]^[6].

In many patients, the cancer has already begun to spread at a microscopic level even before the eye tumor is first diagnosed, though it may not be detected for months or years^[17]. When uveal melanoma spreads to distant organs, the five-year survival rate is about 15%^[2].

The size and location of the tumor affect the risk of spreading. Tumors in the iris are usually small and rarely spread. Tumors in the ciliary body and choroid tend to be larger and carry a higher risk of spreading to other parts of the body^[4]^[10].

Recent advances in understanding the genetics of uveal melanoma have helped doctors better predict which tumors are more likely to spread. Testing the tumor’s genetic characteristics can provide important information about the patient’s prognosis and may help guide treatment and monitoring decisions^[14].

Treatment Options

Treatment for uveal melanoma aims first to eliminate the cancer and second to preserve the eye and vision whenever possible. Fortunately, most patients do not require removal of the eye and can have their cancer successfully treated while keeping their vision^[17].

The main treatment options include^[2]^[6]^[15]:

Radiation therapy is a common treatment that uses high-energy rays or radioactive materials to kill cancer cells. There are two main types. Plaque brachytherapy involves placing a small radioactive disk (plaque) on the outside of the eye next to the tumor for several days, then removing it. The radioactive materials used may include iodine-125, ruthenium-106, palladium-103, or cobalt-60. Teletherapy delivers radiation from outside the body and includes proton beam therapy, helium ion therapy, or stereotactic radiosurgery using specialized machines^[2]^[6].

Surgical resection involves removing the tumor while leaving the eye in place. This is an option for some tumors depending on their size and location^[6]^[17].

Enucleation is the surgical removal of the entire eye. This may be necessary for very large tumors or when other treatments are not suitable^[6]^[15].

Other treatment approaches include laser therapy, such as transpupillary thermotherapy or photocoagulation, and in some cases photodynamic therapy^[2].

For small tumors that are difficult to distinguish from benign moles, doctors may recommend active monitoring with regular eye examinations and imaging to watch for any growth or changes^[17].

While these treatments are usually successful at controlling the cancer in the eye, treatment for large tumors typically results in some loss of vision^[2]. For patients whose cancer has spread to other organs, immunotherapy and other systemic treatments may be recommended^[2].

Treatment decisions should be made in consultation with a specialist who has experience treating uveal melanoma. Patients are encouraged to ask questions, seek second opinions, and learn about all available options, including clinical trials that may be testing new treatments^[1].