Uveal melanoma or ocular melanoma occurs in the cells that produce melanin in the eyes. Melanomas form in the eye where they cannot be seen; so ocular melanomas are difficult to detect. This problem is compounded because ocular melanoma does not cause any early symptoms.

The causes of ocular melanoma are not clearly known. There are three parts in the eye that can be affected. The iris gives the eye its color. The choroid layer is full of blood vessels and tissue and lies between the white of the eye (sclera) and the retina at the back. The ciliary body lies in the front of the uvea (the area between the white of the eye and the retina). It secretes the aqueous humor (the transparent liquid in the eye).

Certain people are at a higher risk of contracting ocular melanoma due to factors like

• Age
  Older people are more prone
• White skin
  People with white skin are at a higher risk
• Light-colored eyes
  People with blue or green eye color
• Ultraviolet exposure
  Prolonged exposure to light from the sun especially during the middle of the day and the use of sun lamps and tanning beds to get a tan are high-risk factors
• Heredity
  Certain inherited conditions such as dysplastic nevus syndrome, and abnormal color in the uvea, called ocular melanocytosis are risk factors
• Gene mutation
  Certain abnormal genes that are passed on from parents to children

The symptoms of ocular melanoma include

• Dark spot on the iris that is growing
• Poor vision or loss of vision in one eye
• Changes in the shape of the pupil (at the center of the eye)
• The sensation of seeing floaters (imaginary specks that look like they are floating in front of the eye)
• Sensation of flashes
• Loss of peripheral vision
• Red, bulging and painful eye

Having ocular melanoma can cause complications such as

• Vision loss due to retinal detachment caused by large melanomas
• A growing melanoma can cause pressure in the eye to increase. Glaucoma can cause eye and redness, and eventually lead to blurry vision
• Ocular melanoma can spread beyond the eye to nearby lymph nodes and later to other parts of the body

Diagnosis is done by tests such as

• Eye examination of the outside of the eye is done to look for enlarged blood vessels.
• The inside of the eye is examined using binocular indirect ophthalmoscopy or slit-lamp biomicroscopy.
• Eye ultrasound uses high-frequency sound waves to produce images of the eye.
• An angiogram of the eye is to view the blood vessels in and around the melanoma.
• An imaging technique called optical coherence tomography is used to create images of the uveal tract and retina.
• A biopsy is done by inserting a needle into the eye and extracting a sample of the suspicious tissue. The biopsy is testing in a laboratory to confirm the presence of melanoma cells.

If the melanoma is in an advanced stage and has spread to other parts of the body, the following tests are done to extent of the metastasis:

• Abdominal ultrasound
• Liver function test
• Chest x-ray
• CT, MRI and PET scans

Very small ocular melanomas may not require immediate treatment. The doctor may want to watch it for signs of growth.

Top treatment options for ocular melanoma are

Surgery
The option to remove the melanoma and a portion of the eye or remove the entire eye (enucleation) by surgery depends on the size and location of the tumor.

Radiation therapy
Melanoma cells are killed by using high energy gamma or proton rays. This method is used for small to medium-sized melanomas.

Laser therapy
Laser therapy is a treatment option in certain situations. One type of laser therapy called thermotherapy uses an infrared laser in combination with radiation therapy.

Photodynamic therapy
Certain medications make the melanoma cells sensitive to light. A light of a special wavelength is beamed on the melanoma killing it and damaging the blood vessels feeding the melanoma. This method is used for small melanoma and is not very effective for large melanomas.