Uveal melanoma

Uveal melanoma is a very rare form of cancer that affects the eye. It starts in pigment cells (melanocytes) that are found either in the iris, muscle fibres behind the iris (ciliary body) or the blood vessels to the eye (choroid). These areas together are known as the uvea.

“Uveal melanoma is now classified as a distinct disease entity (rather than a different form of cutaneous melanoma) and has been granted ‘orphan status’ which means that there are some incentives to encourage new medicines to be developed. It is an exciting time for uveal melanoma as there are new treatments in development which will hopefully be available outside of clinical trials soon.”

 

Dr Paul Nathan, Trustee (consultant medical oncologist, Mount Vernon Cancer Centre)

Types of uveal melanoma

Uveal melanoma is sometimes named by where it is located in the eye:

  • Choroidal melanoma – This occurs in the blood vessels at the back of your eye. It is the most common form of uveal melanoma
  • Ciliary melanoma – This occurs in the ring of muscle fibres behind your iris that help the lens change shape for eye focus
  • Iris melanoma – This occurs in the iris – the area at the front of your eye that gives you your eye colour. It accounts for only 5% of all uveal melanomas and is often smaller and less likely to spread than the other forms

NB: Conjunctival melanoma is cancer that starts in the outer layer (conjunctiva) of the eye. It has more in common with skin melanoma and is not an uveal melanoma, and not covered here.

What are the causes?

The causes of uveal melanoma remain largely unknown. Unlike other types of melanoma, it is NOT linked with harmful sun exposure (some research links it to iris melanoma). However, there have been certain factors shown to could increase your risk. These include having fair skin or a lighter complexion, having blue, green or other light coloured eyes and being older. In some rare cases, there is a faulty gene inherited which may be linked to several types of cancer in the family.

Symptoms

The symptoms of the different types of uveal melanoma can be difficult to pick up. This is because, unlike skin melanoma, you cannot see them. The exception is uveal melanoma in the iris that may appear as a dark area. They may be noticed by the optometrist during a routine eye test. Often, the first signs are discomfort in the eye. 

Possible symptoms you may see:

  • A new dark spot on the iris
  • A change in the size or the shape of your pupil (black area of the eye)
  • Blurred vision or other change in vision
  • Spots that drift in your field of vision
  • Flashes of light
  • A change in the position of your eyeball
  • Pain or discomfort in the eye

If your GP or optician cannot find another cause for these symptoms, you should be referred quickly (normally within about two weeks) to an ophthalmologist in a specialist hospital for tests and further evaluation.

Diagnosis and staging

After a diagnosis of uveal melanoma, your medical team will work out the ‘stage’. The stage is a way of describing the key features of your melanoma and is helpful in guiding the best treatment and follow-up for you. Your stage provides an indication of how advanced your melanoma is. Generally, the higher the stage, the more advanced it is. 
Staging for uveal melanoma follows the American Joint Committee on Cancer (AJCC) Tumour, Node, and Metastasis (TNM) classification. Details of which can be found here.
We also have more information for patients on TNM staging on our site here.

Factors that can affect staging and prognosis include:

  • The location of the melanoma
  • The size of the melanoma
  • Whether the ciliary body has been involved
  • Whether the melanoma has started to grow outside of the eye or spread to other parts of the body, usually the liver (metastasis)

Treatment

There are a number of initial treatments available for uveal melanoma. None have been generally proven better than the another. We cover them in more detail in our patient guide.

These can include:

Surgery

The main treatment for a mucosal melanoma is surgery, which should be done by a surgeon who is very experienced in complex head and neck surgery. This is often in a specialised centre where there would be support from an experienced cancer team.

  • Surgery: minimising damage to the eye
  • Radiation therapy: These therapies target the melanoma with radiation
  • Phototherapy: This can involve a laser treatment that targets the melanoma with an infrared laser beam. Other types of phototherapy include the use of a dye in combination with a laser treatment

Other possible treatments

If your uveal melanoma has recurred or spread to another part of the body, you may be tested for a gene (HLA-A*02:01). If you test positive for this gene, you may be offered a new drug called tebentafusp.

For more information on clinical trials, please visit the Melanoma TrialFinder

If you have any questions about your diagnosis or treatment, our specialised Melanoma Helpline nurses are here to support you on 0808 801 0777