Eye cancer, also known as ocular cancer, is rare, with around 430 cases diagnosed in the UK each year.
There are a number of different types of cancers that affect the eye. These include:
melanoma of the eye – this can be intraocular, conjunctival or skin melanoma
basal cell carcinoma
squamous cell carcinoma
sebaceous cell carcinoma
retinoblastoma – a childhood cancer
Cancer can sometimes develop in the tissues surrounding your eyeball, such as your eyelids, orbit or lacrimal gland. It can also spread to the eye from other areas of the body. This is known as a secondary cancer or a metastasis.
Melanoma is the most common type of intraocular eye cancer, and this topic focuses mainly on this type of eye cancer. See the Cancer Research UK website for more detailed information about other types of eye cancer.
Symptoms of eye cancer
There are a number of different symptoms of eye cancer including:
bulging of one eye (proptosis)
total or partial loss of vision or blurred vision
pain in or around your eye, although this is rare
a change in the appearance of the eye or surrounding tissues
You may also experience:
flashes of light, spots, or wiggly lines in front of your eye
a lump on your eyelid or in the eye that's increasing in size
Many of these symptoms are common to other eye conditions, and if you have them it may not necessarily mean you have cancer of the eye.
However, it's very important that these types of eye symptoms are checked by a doctor as soon as possible. The sooner cancer is diagnosed, the easier it is to treat and the greater the chance of treatment being successful.
Melanoma of the eye
Melanoma is cancer that develops from pigment-producing cells called melanocytes. Most melanomas develop in the skin, but it's also possible for them to occur in other parts of the body, including the eye.
Ocular melanoma usually starts in the eyeball, although occasionally it can begin in the eyelid or conjunctiva (the thin mucous membrane that covers the front of the eye).
The symptoms of ocular melanoma include a sudden blurring of vision and seeing flashing lights and shadows. It sometimes doesn't cause any symptoms and is picked up during a routine eye test.
You should visit your GP if you experience these eye symptoms, so that they can be investigated further.
The risk of developing melanoma of the eye increases with age, with most cases being diagnosed in people in their 50s.
What causes eye melanoma?
The following factors increase your risk of developing melanoma of the eye:
lighter eye colour – if you have blue, grey or green eyes, you have a higher risk of developing eye melanoma compared to people with brown eyes
unusual moles – if you have irregular shaped or unusually coloured moles, you're more at risk of developing skin cancer and eye melanoma
over-exposure to sunlight – a known risk factor for skin cancer, this may also be a risk factor for eye melanoma (although there's currently no firm scientific evidence to support this)
exposure to ultraviolet radiation – there's some evidence to support a slightly increased risk of eye melanoma in people who work as welders
Diagnosing melanoma of the eye
An ophthalmologist (a specialist in diagnosing and treating eye conditions) will examine your eyes.
If they suspect you have melanoma of the eye, they'll refer you to a specialist centre for eye cancer. There are four centres in the UK, located in:
At the centre, it's likely you'll have a number of different tests. You'll have another eye examination to look at the structures of your eyes in more detail and to check for abnormalities.
Eye drops may be put in your eyes, which may temporarily affect your vision. You should therefore ask a friend or relative to drive you to and from your appointment.
You may also have an ultrasound scan of your eye. A local anaestheticeye drop will be put in your eye. A small probe will be placed over your closed eye with a small amount of lubricating jelly to make it more comfortable.
You may also have a fluorescein angiogram. This is where photographs of the suspected cancer are taken using a special camera. You'll have an injection of dye (fluorescein) into your arm, which will travel through your bloodstream to the blood vessels of your eye. The dye in the blood vessels shows up on the images, which provide useful information about the tumour.
Cytogenic testing is another type of test you may have. This is where a small sample of the tumour's cells (a biopsy) is taken to check for chromosomal abnormalities. This information can be used to help determine the grade of the melanoma and prognosis (outlook).
Treating eye cancer
Radiotherapy, chemotherapy and surgery are the three main treatments used for eye cancer. The type of treatment you'll have will depend on:
the type of eye cancer you have
the size of the tumour and how far it has spread
your age, overall health and level of fitness
You'll probably be treated at a specialist eye cancer centre. It may be that only one type of treatment is suitable for you, or several options may be possible. Your care team will explain each treatment option in detail, including the benefits and any potential complications.
Treating melanoma of the eye
Treatment for melanoma of the eye will depend on the size and location of the tumour inside your eye.
If the tumour is very large, you may need to have your eye removed (enucleation). Enucleation may also be necessary if your eye is red and painful with raised intraocular pressure.
In more advanced cases of ocular melanoma, the tumour may have spread outside the eye. This is known as extraocular melanoma. If this is the case, you may need surgery to remove your eye, plus further surgery to the eye socket to ensure that all the cancer has been removed. You may also need radiotherapy.
If there's still some vision in your eye, your doctor may try to preserve your eye by removing the tumour (local resection) or using radiotherapy.
Approximately two thirds of people with ocular melanoma have radiotherapy treatment. The radiotherapy treatments often used include:
proton beam radiotherapy
If the melanoma is in the iris (coloured part of the eye), you may also have local resection, plaque brachytherapy or proton beam radiotherapy. Pure iris melanoma has the best prognosis.
Outlook for melanoma of the eye
The outlook for ocular melanoma depends on how advanced the cancer is at the time it's diagnosed and which parts of the eye are affected.
The five year survival rates for different stages of ocular melanoma are as follows:
early stage small melanoma – 84 people out of 100 (84%) will live for at least five years after diagnosis
medium stage eye melanoma – about 68 out of 100 (68%) will live for at least five years after diagnosis
large eye melanoma – about 47 out of 100 people (47%) will live for at least five years after diagnosis