Ocular Melanoma, Eye Melanoma is the most common life-threatening form of eye cancer, common in adults, also very rare. According to Ocular Melanoma Foundation, Ocular Melanoma is diagnosed in about 2500 adults every year in the United States and occurs most often with individuals with a median age of 55 years. However, the disease can occur in all race at any age [].
Cancer starts when cells in the body start growing out of control. Generally, the healthy cells in the body follow a systematic path of growth, division, and death. But when the orderly pathway of cell death known as apoptosis breaks down, cancer begins to form.
Eye cancer can occasionally develop in the tissues around the eyeball or spread to the eye from other body parts like lungs and breasts.
What is Eye Cancer or Ocular Melanoma?
Ocular Melanoma, also known as Eye Melanoma, is one of the rarest forms of cancer and mostly affects the inner portion of the eyeball. This is a type of cancer that develops in the cells that produce pigments, Melanin. The pigment is the substance that gives colour to your eyes, hair and skin. Just like the development of melanoma on your skin, it can also develop inside your eyes or your conjunctiva. Eyeball consists of three layers. The outer layer of the eye is the sclera, the innermost layer is the retina, and the middle layer is the uvea. Eye Melanoma usually begins in the middle of the three layers of the eye. However, in a rare case, ocular melanoma can also occur on the conjunctiva. If cancer starts inside the eyeball, it’s termed as intraocular cancer. There are two predominant forms of intraocular cancers or intraocular melanomas .
Primary Intraocular cancers are those that start inside the eyeball. In children, cancer of the retina, the retinoblastoma (cancer that begins in the retina) is the most common primary intraocular cancer. Whereas in adults, the most common intraocular cancers are Melanoma and Lymphoma.
Secondary intraocular cancers are those forms of cancer that first start in other areas of the body and then eventually spread to the eyes, causing the melanomas. Therefore, they cannot be termed true eye cancers. The most common cancers that spread to the eye are breast cancers and lung cancers. Most often, these cancers spread to the part of the eyeball called the uvea [].
Symptoms of Eye Cancer
Generally, in its early stage, there are no obvious symptoms of eye melanoma as most melanomas develop in the part of the eye you cannot see. The condition can sometimes be detected only during a routine eye check-up. Nevertheless, some of the common symptoms of intraocular melanoma or eye cancer include:
- Blurred Vision
- The appearance of a dark patch in the conjunctiva
- A sensation of light, shadows, seeing spots and wiggly lines in your vision
- Partial or complete loss of vision
- The appearance of a lump on the eyelid or in the eye getting bigger over time
- Bulging of the eye
- Painful feeling in and around the eye
- A change in the shape of the pupil
- Having a dark spot on the iris, 
Causes of Eye Cancer
The exact cause of the development of eye cancers, particularly primary intraocular cancers like intraocular melanoma and retinoblastoma, are still not clear. Several reasons ranging from heredity to excessive exposure to UV radiations can be the primary cause of the disease. Overexposure to the sunshine may increase the risk, but the research has not confirmed this.
People with light eye colour like blue or green eyes have a higher risk of melanoma of the eye. Notably, the risk increases along with age.
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Risk Factors for Eye Melanoma
- Race/Ethnicity– Studies have shown that White American are at higher risk of eye cancers than African Americans or Asian Americans.
- Age: Ocular Melanoma is most common in older people. In a survey of ocular melanoma patient, it was found that about 67.7% were aged between 50-79 years, 21% were below 50 years, and 11.3% were above 80 years. The average age of diagnosis is around 55 years.
- Eye colour– People with light coloured eyes are also more prone to intraocular melanoma
- Gender– Eye Melanoma is slightly common in men than in women.
- Inherited disorders such as Dysplastic Nevus Syndrome (those who have abnormal moles on the skin) have a higher risk of developing melanoma of the eye.
- Moles- People with atypical moles have a higher skin or eye melanoma than the average person.
- Inherited Cancer Syndromes- Doctors have identified a rare inherited condition called BAP1 cancer syndrome. Families with this syndrome have an increased risk of uveal melanoma, skin melanoma and other cancers.
- Exposure to Ultraviolet (UV) radiation- Some studies have reported a slightly increased risk of eye melanoma in people working as welders. This may be due to exposure to ultraviolet radiation as UV rays cause melanoma of the skin.
- Use of sunbeds. Overexposure to artificial UV radiation increases the risk of eye melanoma.
Eye Cancer Treatment
Treatment for eye cancer or melanoma depends on the size and location of the tumour. Some of the most common treatment options are:
- Brachytherapy, The most common method of treating eye melanoma with radiotherapy, is Brachytherapy, i.e. plaque therapy. This is the treatment of cancer by the insertion of radioactive implants directly into the tissue.
- External Radiotherapy: Sometimes, external beam radiotherapy may be used with a specialized technique called proton beam radiation. This therapy uses a machine outside of the body that delivers laser beans to the eye to destroy cancer cells.
- Surgery for the removal of the tumour or affected a part of the eye: It includes iridectomy (removal of part of the iris), Sclerouvectomy/Endoresection (surgery to remove the choroidal tumour while keeping the eye), Enucleation (removal of the eye).
- Removal of the eye if the tumour is large.
- Radiation Therapy uses high-energy X-rays or other particles to destroy cancer cells. The most common type of radiation treatment is called external-beam radiation therapy, which is radiation given from a machine outside the body.
Chemotherapy is rare in the case of eye melanoma, but it may be suitable for other types of eye cancer.
Can Eye Cancer Be Prevented?
The actual cause of most eye cancers is yet to be discovered, so it is not possible yet to give any prevention techniques. However, there is a link of sunlight and melanomas of the skin, so limiting exposure to intense sunlight is a good practice. The American Cancer Society recommends wearing UV-protected sunglasses in strong sunlight. This might help reduce the risk of developing cancers of the skin around the eyes. The link between UV rays and eye melanomas is not proven. However, doctors think that sunglasses might also reduce eye melanoma risk.