What is Ocular Melanoma?
Ocular melanoma is an eye cancer that develops from cells called melanocytes. Melanocytes produce the dark-coloured pigment melanin, which is responsible for the colour of our skin. These cells are found in many places of the body, including: the skin, hair and lining of the internal organs, as well as the eye.
Most of the time melanomas begin to grow on the skin, but it is possible for a melanoma to develop in other parts of the body, such as the eye. An ocular melanoma can develop in a variety of anatomical places within the eye. Uveal melanoma is the most common type; this tumor occurs along the uveal tract of the eye, which includes the choroid, ciliary body and iris.
The choroid is part of a layer found within the eyeball. The choroid is darkly pigmented to prevent light from reflecting inside of the eye. The ciliary body extends from the choroid and helps the eye focus by changing the shape of the lens. The iris is the coloured disc at the front of the eye whose job is to control the amount of light that enters the eye. All these structures within the eye are coloured with melanin. A melanoma can also be present in the thin lining over the white part of the eye (the conjunctiva) or on the eyelid, but are very rare. This is known as conjunctival melanoma. The ocular melanoma is the most common type of cancer to affect the eye, although it's still quite rare.
What causes Ocular Melanoma?
Doctors know that a melanoma occurs when there is an error in the DNA of healthy eye cells. The error in the DNA code tells the cells to grow and multiply rapidly, but these mutated cells go on living and accumulating in the eye to form an eye melanoma. The cause of the tumor is unknown but there are some theories that show how exposure to ultraviolet (UV) rays will increase the risk of developing a melanoma of the skin. People who have fair coloured skin, hair, eyes and who get skin burns easily are higher at risk to develop a melanoma. Ocular melanoma may also be more common in people with atypical mole syndrome/dysplastic nevus syndrome. People with this condition have over 100 moles on their body that are abnormal in size and shape, thus making it a greater risk for developing a melanoma of the skin.
Symptoms ofOcular Melanoma
Symptoms of an ocular melanoma include blurred vision, seeing flashing lights and shadows. However, patients are usually asymptomatic and can be diagnosed by an optometrist during a routine comprehensive eye exam.
What are the risks of having Eye Melanoma?
Risk factors for primary melanoma of the eye include:
- Light eye color.
- Being pale skinned.
- Increasing age.
- Certain inherited skin disorders.
- Exposure to ultraviolet (UV) light.
Are there any complications?
Complications of eye melanoma may include:
- Increasing pressure within the eye (glaucoma). A growing eye melanoma may cause glaucoma. Signs and symptoms of glaucoma may include eye pain and redness, as well as blurry vision.
- Vision loss. Large eye melanomas often cause vision loss in the affected eye and can cause complications, such as retinal detachment, that also causes vision loss. Small eye melanomas can cause some vision loss depending on the location of it inside the eye. Very advanced eye melanomas can cause complete vision loss.
- Eye melanoma that spreads beyond the eye. Eye melanoma can spread outside of the eye and to distant areas of the body, including the liver, lungs and bones.
Are there any Treatment?
A number of different treatments are used for ocular melanoma. The treatment modality depends on the size, cell type and position of the tumour and on other factors such as your general health and level of vision in both eyes. The aim of treatment is to destroy the cancer cells, stop the cancer from coming back and to save as much vision as possible.