Ocular melanoma

This information sheet has been written to provide information on ocular melanoma (melanoma of the eye). Ocular melanoma is a rare cancer. Melanoma is a cancer of the cells called melanocytes. Melanocytes produce the dark coloured pigment melanin, which is responsible for the colour in the skin. These cells are found in many parts of your body, including the skin, hair and lining of the internal organs, including the eye.

The eye

Parts of the eye

  • iris (the coloured part of the eye)
  • ciliary body (the muscle that focuses the eye)
  • choroid (part of the lining of the eyeball)
  • vitreous body (the clear, colourless jelly that fills the back part of the eye)
  • lens (the transparent disc behind the iris that helps the eye to focus)
  • cornea (the transparent membrane that covers the iris and pupil).

Most melanomas of the eye are in the uvea, which includes the ciliary body, choroid, and iris. This is known as uveal melanoma.

Melanoma can occur on the white part of the eye (the conjunctiva) or on the eyelid but this is very rare. This is known as conjunctival melanoma. Eyelid melanomas are the same as a melanoma on the skin anywhere else.

The exact cause of ocular melanoma is unknown. Uveal melanoma is more likely in people with light-coloured eyes and in older age groups. It may be linked to sun exposure. It is more common in people that have atypical mole syndrome. Atypical mole syndrome is when the person has 100 or more moles, and at least three of these moles are unusual in size and shape.

Signs and symptoms

Usually, there are no symptoms and ocular melanoma is found during a routine eye check. Those with symptoms usually just have decreased vision, some- times they have lost a bit of their side vision.

Diagnosis

It may be diagnosed by using a number of different types of scans and photography, and, occasionally, biopsy (removing a small sample of tissue).

Treatment

Treatment depends on the size, cell type and position of the melanoma in the eye.

Radiation treatment

Recent developments in radiation treatment mean that it is often possible to save sight in the eye completely or partly.

External radiation

Radiation treatment is the use of high energy radiation to destroy cancer cells or prevent them from reproducing. Radiation treatment only affects the part of the body at which the beam(s) is aimed so is localised.

Treatment is normally given as small doses, called fractions, over a few weeks.

Internal radiation

A radioactive source called a plaque (a small disc) is placed over the melanoma during an operation.

The disc stays in place for about 80-120 hours (about four days) until the total dose of radiation has been given. Usually, you’ll have a general anaesthetic and will need to stay in one room until the plaque is removed. The operation takes about an hour. Removal of the plaque is also done under anaesthetic and takes about 15 minutes to remove.

Treatment is only offered in a few specialist centres in New Zealand. Usually, there are two trips: one to do the special tests needed to plan the treatment, then a couple of weeks later, you go there for about five to six days for the actual treatment.

If you need to travel out of your home town for treatment, you may be eligible for National Travel Assistance. Speak to your doctor or social worker about this. For more information visit their website:

http://www.health.govt.nz/publication/national-travel-assistance-scheme-your-guide-claiming-travel-assistance-brochure

Surgery

This may involve just the melanoma, a small part of the eye, or sometimes, the whole eye. The type of surgery you have depends on the size and position of the melanoma.

The surgery is done by a specialist eye surgeon under a general anaesthetic. There are only two surgeons in New Zealand that do this and they are in Christchurch and Auckland.

Conjunctival melanoma

This is diagnosed by taking a small sample of cells from the pigmented area (a biopsy). Treatment includes surgery and chemotherapy (eye drops). Radiation treatment is very occasionally used.

Reviewed by Professor Mark Elder, ophthalmologist, Christchurch

This information sheet was reviewed in 2013 by the Cancer Society of New Zealand. The Cancer Society’s information sheets are reviewed every three years.