Uveal Melanoma

Uveal melanoma is a rare eye cancer of the uvea or Uveal tract; a Uveal melanoma is a tumour. The Uvea or Uveal tract in both eyes is made up of the iris, ciliary body and choroid; it is often referred to as the middle layer of tissue in the wall of the eyeball. The iris is the coloured part of your eyes, the choroid is a layer of connective tissue and blood vessels, it is located between the retina & sclera, and the ciliary body is housed near the iris, it produces aqueous humor. Uveal melanoma can affect any of the three parts that make up the uvea or Uveal tract.

Uveal melanoma is caused by melanocytes cells found in the uvea.

Some patients may not even be aware that they have a Uveal melanoma tumour and is detected on a routine eye test.

Others may experience (dependent on where the tumour is)

• Flashing lights in your vision

• Floaters in your vision

• Shadow in the eye

• Blurring of the vision

• Loss of peripheral vision or an area of your peripheral vision

• Growing dark spot on the iris

• Change in the shape of your pupil

There is no known cause of Uveal melanoma. Medical research has shown that healthy eye cells that develop DNA faults; begin to mutate, replicate and accumulate to form a Uveal melanoma.

Risk factors associated with Uveal melanoma are:

• Light coloured eyes

• Fair skin

• Caucasians

• Older age of 55-60yrs

• People with moles

• Benign moles

• Skin melanoma

• Genetic mutations

• Abnormal skin pigmentation of the eyelids, face, Uveal tract, known as ocular melanocytosis

• Possible overexposure of UV– this is still debated and not proven

Uveal melanoma treatment is dependent on the location and size. The treatment options available are:

• Iridotomy is the surgical removal of small Uveal melanoma(s) on the iris, removal of iris melanoma(s). The iris melanoma is removed under general anaesthetic.  Surgery is often followed with ruthenium plaque brachytherapy.

• Surgical removal of small Uveal melanoma tumours at the front of the Uveal tract can be removed under general anesthetic. Surgery is often followed with ruthenium plaque brachytherapy.

• Ruthenium plaque brachytherapy is a where a radioactive plaque (small metal disc) is surgically attached to your eye to treat the Uveal melanoma tumour.  The radioactive material inside the plaque is called ruthenium. You will need to stay in hospital to be monitored, this can last up to a week, and the plaque is then removed after the treatment period. This treatment has a high success rate in small to medium sizes Uveal melanomas.

• Proton beam radiotherapy is where hydrogen ions (protons) are accelerated and are used to target the Uveal melanoma tumour. This treatment has a high success rate in medium size Uveal melanomas.

• Photodynamic therapy is when a drug called visudyne, also known as Verteporfin, is injected into your arm. The drug then travels to the eyes; a laser is then used for 1 minute to activate the visudyne in the required area to treat the Uveal melanoma. This is usually only used on small Uveal melanomas of the choroid.

• Removal of the eye is called Enucleation. This is reserved for very large Uveal melanoma tumours that cannot be treated with the above. Enucleation is used when the Uveal melanoma tumour is growing through the eyeball wall and/or you have high eye pressure, which is causing severe pain.

• Exenteration is the removal of the eye and surrounding tissue. This option is used if the Uveal melanoma has extended through the eyeball and reached surrounding tissue and cannot be treated with just removal of the eye (Enucleation).