An ocular melanoma is the most common type of eye tumour.
What is an ocular melanoma?
An ocular melanoma is the most common type of eye tumour. It develops from cells called melanocytes, which are found in the uvea (the middle layer of tissue around the eyeball that includes the choroid, the ciliary body and the iris). Ocular melanomas usually affect one eye only.
What is the cause of an ocular melanoma?
There is no known cause of ocular melanoma, and it is not linked to skin melanoma. It is a very rare form of cancer affecting between only five and seven people in every million each year. It is more common in fair skinned, blue-eyed people. The average age from which an ocular melanoma develops is 55 years.
What are the symptoms of an ocular melanoma?
For some people there may not be any symptoms and the tumour is found during a routine eye test. For others, it can cause visual disturbances such as flashing lights or a shadow.
What are the treatment options?
The appropriate treatment depends largely on the size and location of the melanoma, as explained below.
Enucleation (removal of the eye)
We usually only consider removal of the eye if:
- Your tumour is relatively large, which increases the risk of having a painful blind eye following conventional treatment
- You have other problems with your general health
- You decide that removing your eye is a better choice than other kinds of treatment
Ruthenium plaque treatment
A plaque is surgically placed on the surface of the eye to treat the tumour in your eye. The plaque is made of a radioactive isotope of ruthenium (a chemical element). Plaques are availablein different sizes meaning the correct size can be used for each patient.
Stereotactic radiosurgery is a type of radiation treatment that uses gamma rays. Gamma rays are different from the x-rays used in a standard x-ray in that they have a much shorter wavelength. These gamma rays are directed at the tumour in your eye.
Proton beam radiotherapy
Protons are hydrogen ions that are accelerated to a high energy so that they are able to penetrate tissue to a specific, clearly defined depth and area. This means they are very practical for treating small areas of the eye. The treatment works by sterilising the tumour cells so that they can no longer reproduce. The results can vary depending on the size of the tumour, but for small lesions the success rate is high. Larger lesions carry a greater risk of complications.
Local resection (surgical removal of the tumour)
Small melanomas near the front of the inside of the eye can occasionally be surgically removed under general anaesthetic.
Iridectomy (surgical removal of iris melanoma)
Small melanomas on the iris (the coloured part of the eye) can occasionally be surgically removed under a general anaesthetic.
Photodynamic therapy involves the slow injection of a drug, called visudyne (verteporfin), through a vein in your arm. Once the injection has been performed, a low power laser is shone into the eye and focused on the area being treated for just over a minute to activate the visudyne.