What Is Uveal Melanoma?

Uveal melanoma is a rare form of eye cancer that many patients may not be aware they are even at risk for.

According to the American Cancer Society, there will be approximately 3,360 new cases of eye cancers in 2022 (1,790 in men and 1,570 in women) with about 410 deaths. And although it is not as common or aggressive as other cancers, it is important to understand who is at risk, what to look out for and how it is diagnosed.

Signs, Symptoms and Presentation

Uveal melanoma is found in the uvea or uveal tract which is one of the three layers of the wall of the eye that is made up of the iris (the colored area at the front of the eye), the ciliary body (which is a ring of muscle tissue behind the iris that changes the size of the pupil) and the choroid (which is a layer of blood vessels that bring oxygen and nutrients to the eye).

Melanomas can arise in any of those parts of the eye and will have different behaviors and looks. In the iris, tumors usually are small and grow slowly, rarely spreading to other parts of the body. In the ciliary body, the tumors are often larger and more likely to spread to other parts of the body, and the same goes for the choroid — this is the most common site where uveal melanoma is found.

Some symptoms of uveal melanoma, according to Columbia University’s Department of Ophthalmology, include:

• Blurred or change in vision.
• Floaters (spots that drift in your field of vision).
• Flashes of light.
• A dark spot on the iris.
• A change in the size or shape of the pupil.
• A change in the position of the eyeball in the socket.

Causes and Risk Factors

Different cancers are associated with a multitude of risk factors that increase the chance of diagnosis, some of which can be changed but some are inherited. However, having a known risk factor of the disease does not mean a person is guaranteed to have it. Some known risk factors associated with uveal melanoma, according to the American Cancer Society, include:

1. Race and ethnicity. The risk of uveal melanoma is much higher in White patients compared to Black, Hispanic or Asian American patients.
2. Eye color. People with light colored eyes are more likely to develop uveal melanoma compared to those with darker colored eyes.
3. Age. Uveal melanoma can be diagnosed at any age, but the risk is greater as people get older.
4. Gender. Slightly more common in men than women.
5. Family history. It is very rare, but some uveal melanoma runs in the family — of note, this risk is still under investigation.

Different types of moles in the eye or on the skin have also been associated with an increased risk of melanoma. In the eye these include choroidal, giant choroidal and iris nevi; on the skin it includes atypical nevi, common nevi and freckles.

Other risk factors for uveal melanomas include certain inherited conditions. One of these includes dysplastic nervus syndrome, which consists of many abnormal moles on the skin. Another risk factor is oculodermal melanoma, which is abnormal brown spots on the uvea. And BAP 1 cancer syndrome, which is a rare inherited condition in family members that increases the risk for uveal melanoma, as well as other cancers; this specific condition is an inherited mutation and usually forms aggressive cancers at younger ages.

Additionally, there are some unproven risk factors that are still under investigation. Some of these include certain occupations, such as welders.

Most notably, it is still unknown if sun and UV light exposure increase the chance of developing uveal melanoma — although it is one of the biggest risk factors for general melanoma — there are still studies investigating the potential association.

Diagnosis

Uveal melanoma is uncommon and there is no widely recommended screening test for those who may be at risk. Most are detected by a routine eye exam which includes dilating the pupil and examining the eye in detail, according to information from the University of Michigan Health Kellogg Eye Center. The eye exam is typically done with tools such as an ophthalmoscope, indirect ophthalmoscope or slit lamp and a gonioscopy lens.

Although there is no universal screening process for those at a higher risk for uveal melanoma, it can still be caught at an early stage. Some physicians may require people who have those inherited risk factors to have an eye exam more than the typical once per year checkup.

Of note, sometimes these tumors grow so fast that they might have been missed during a patient’s last routine eye exam, so if one begins experiencing any of the symptoms, the American Cancer Society suggests getting another exam.