Sunday, September 19, 2010

Eye cancer

Cancer of the eye is rare in the UK. Around 350 people get eye cancer each year. It's usually treated with surgery, radiotherapy or chemotherapy.
• About eye cancer
• Types of eye cancer
• Symptoms
• Causes
• Diagnosis
• Treatment
• Further Information
• Sources
• Related topics
About eye cancer
Eye cancer is caused by an uncontrolled growth of cells. It can develop in or around the eye. There are several different types of eye cancer.
Types of eye cancer
Cancer that develops in the eye is called intraocular cancer. Cancer that develops outside the eye is called extraocular cancer. Below are the most common types.
Intraocular cancers
Non-Hodgkin's lymphoma
This type of cancer usually develops in lymph nodes. The lymph nodes are glands throughout your body that make up part of your immune system (the system that helps protect your body from infections). However, non-Hodgkin's lymphoma sometimes develops in the eye.

Ocular melanoma
Melanoma develops from cells that contain the pigment melanin. It most commonly occurs on the skin. But it can also develop inside the eye, where it is called ocular melanoma.
Melanoma is the most common type of intraocular eye cancer, though it's still rare. It is most commonly diagnosed in people over 50.
Ocular melanoma usually develops in the uveal tract in the eye. The uvueal tract consists of the choroid layer (the lining of your eyeball), the ciliary body (which contains the muscles that focus the eye), and the iris (the coloured part of your eye). Melanoma can also starts in the inner surface of eyelids (conjunctiva) or the eyelids.

Retinoblastoma
This type of intraocular eye cancer develops in young children, usually under the age of 5. It is often inherited. In nine out of 10 cases it can be cured.

Extraocular cancer
Non-melanoma skin cancers
• Basal cell carcinoma is the most common type of skin cancer in the UK. It often develops near your eye, especially on the lower eyelid. It causes a small red growth on the skin that often has a pearly edge to it. It doesn't usually spread to other parts of the body but it can affect surrounding tissue if it isn't treated. Basal cell carcinoma can usually be removed with surgery if caught early, but sometimes radiotherapy is used to treat it (see Treatment).

• Squamous cell carcinoma is another type of skin cancer that can develop on the skin of your eyelid, but it is quite rare. It develops on the surface of the eyeball or the conjunctiva. It can sometimes spread to lower levels of the skin. It's usually treated with radiotherapy, although it may need surgery as well (see Treatment).


Rhabdomyosarcoma
This is a very rare extraocular cancer that most commonly affects children. It develops in the muscles that move the eye.
Optic nerve tumours
Rarely, a tumour can develop in your optic nerve. The optic nerve connects your eye to the brain. Optic nerve tumiurs are usually treated with surgery (See Treatment).


Symptoms
The symptoms of eye cancer vary depending on the type of cancer and where it is located.
Intraocular cancers such as ocular melanoma have no symptoms. They are usually detected in routine eye examinations. This is one of the reasons it's important to have regular eye tests. The College of Optometrists recommends having an eye examination every two years unless you are advised otherwise.
Some eye cancers cause symptoms. However it's important to remember that these are usually caused by other eye problems and only rarely mean that you have eye cancer. These symptoms are:
• loss of some or all of your vision
• flashing lights or spots in your vision
• a dark spot on your iris that is growing
• a visible lump on your eyelid with crusting or bleeding
• pain in or around the eye (although this is rare with cancer)
• bulging of an eye
In children a squint or odd looking pupil may be a symptom of retinoblastoma. If you notice this, you should take your child to your doctor.
Causes
The exact reasons why cancer of the eye develops aren't fully understood. However, some things increase your risk of certain types. For example:
if you have blue, grey or green eyes you are more likely to develop melanoma of the eye.
• if you have lots of moles that are unusually shaped or especially large (a condition called atypical mole syndrome) this may increase your chances of developing melanoma of the eye
• exposure to ultraviolet rays (UV) in sunlight increases your risk of getting melanoma of the eye - wearing UV protective sunglasses can reduce your exposure
• having a weakened immune system increases your chances of developing lymphoma of the eye
• retinoblastoma is often caused by inheriting a faulty gene from your parents
Diagnosis
If your doctor thinks that you have cancer of the eye, he or she will arrange for you to have some tests to help with diagnosis. You may be referred to a doctor who specialises in eye conditions (an ophthalmologist), and perhaps to a doctor who specialises in cancer (an oncologist) as well.
There are several different types of tests you could have, depending on the type of cancer you are suspected of having.
Ophthalmoscopy
This test is similar to a regular eye test. Your ophthalmologist will use several different instruments to examine the inside of your eye.

Fluorescein angiography
In this test, a dye called fluorescein is injected into your arm. This travels through your blood to vessels in your eyes. A photograph of your eye is taken with a special camera fitted with filters that make the dye visible. The blood vessels inside your eye can then be examined on the photograph.
Ultrasound scan
After giving you some eye drops, your doctor will move a small ultrasound probe over the surface of your eye (through closed eyelids) or on the skin around it. The probe produces sound waves which are used to create an image of the inside of your eye.
Computerised tomography (CT) scan
You may have a CT scan of your head. A CT scan uses X-rays to make a three-dimensional picture of the inside of a part of your body. This helps to show up tumours in and around your eye and whether they have spread.
Magnetic resonance imaging (MRI) scan
An MRI scan uses magnets and radio waves to produce images of the inside of your body. This is sometimes used to find eye tumours.
Biopsy
Sometimes your doctor will want to take a biopsy. A biopsy is a small sample of tissue. This will be sent to a laboratory for testing to find out what type of cancer you have. The procedure can be carried out under local or general anaesthetic.
Treatment
The treatment you will receive will depend on the type of eye cancer you have, how far it has spread and your general state of health. There are three main treatments for eye cancer.
Surgery
Some eye tumours can be removed by surgery. This can involve removing just the tumour, or the part of the eye it is growing in. Surgery is usually enough to remove most tumours of the eyelids. It's sometimes combined with radiotherapy for treating intraocular tumours.
Some tumours, such as melanoma of the eye, can be treated with laser therapy, which is used to kill the cancer cells.
Occasionally the tumour has spread too far to be safely removed on its own and the whole eyeball may need to be taken out (enucleation). Having this treatment can make people feel upset or worried about how they will cope. The doctors and nurses looking after you will support you during this time and will be able to help and advise you. An artificial (prosthetic) eyeball can be created to match your remaining eye.
Remembered that eye cancer is very rare. Most eye symptoms are due to other causes. However, having a regular eye check is important, as is seeing your doctor if you have any symptoms that you are concerned about.
Non-surgical treatments
Radiotherapy
Radiotherapy uses radiation to kill cancer cells. It is often used for treating melanoma of the eye.
A beam of radiation is targeted on the cancerous cells, which shrinks the tumour. Alternatively a source of radiation is implanted next to the tumour in an operation. This is called brachytherapy. You will need to stay at hospital until it's removed in another operation about a week later.
Chemotherapy
Chemotherapy uses medicines to destroy cancer cells. There are lots of chemotherapy drugs. They are usually injected into a vein but sometimes you may be given tablets.
These drugs can cause a variety of side effects, such as making you feel tired or ill. They can also cause nausea or hair-loss. Your specialist will advise you about what side effects to expect.
Chemotherapy can be effective for treating lymphoma of the eye and retinoblastoma. It isn't usually used for melanoma of the eye unless other types of treatment haven't worked.
Sources
• Series mb1 no. 35: Cancer statistics registrations. Office of National Statistics, 2004. www.statistics.gov.uk, accessed 23 August 2007
• Eye cancer overview. Cancer Research UK. www.cancerresearchuk.org, accessed 03 September 2007
• Melanoma of the eye (ocular melanoma). Cancerbackup. www.cancerbackup.org.uk, accessed 23 August 2007
• Cassidy J, Bissed D, and Obe RAS. Oxford handbook of oncology: Oxford University of Press, 2002: 458, 486
• 10 reasons for having an eye examination. College of Optometrists. www.college-optometrists.org, accessed 29 August 2007

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