Introduction  

Ocular melanoma occurs when the cells responsible for color and pigmentation form tumors in the iris or other areas at the center of the eye.
Ocular melanoma is a common cancer of the eye. Every year, up to 2,500 adults in the U.S. are diagnosed with eye melanoma. This condition is more common among light pigmented people who are around the age of 55 years. Eye melanoma can also occur at any age and affects all races. 
The condition is similar to skin melanoma in that it is a silent killer, barely understood. In most cases, it develops in the choroid but it may also develop in the ciliary body and the iris.

Also Known As

  • Uveal melanoma
  • Eye melanoma
     

Sub-Types

  • Choroidal melanoma
  • Ciliary body melanoma
  • Iris melanoma
     

Causes and Risk Factors

The cause of eye melanoma is still unclear. It is believed to be caused by errors that form in the DNA of a person’s eye. The errors instruct the cells to mutate when they should actually die. These mutated cells form in the eye resulting in eye melanoma.
The following factors increase one’s chances of contracting ocular melanoma:

  • Old age
  • Light-colored eyes
  • Caucasian descent
  • Abnormal skin pigmentation that extends to the eye lids and the uvea
  • Long exposure to artificial and natural sunlight
  • A mole in one’s eye or eye surface
     

Signs & Symptoms

In some cases, eye melanoma develops with no signs and symptoms. However, in cases where they occur, one may experience:

  • Blurry or poor vision
  • A dark spot developing on the iris
  • Specks or flashes in one’s vision (floaters)
  • Losing one’s peripheral vision
  • A change in one’s pupil (dark circle in the middle of the eye)
     

Diagnosis

A diagnosis of eye melanoma may involve any of the following tests:

  • Eye exam -  This test is used to probe the exterior of the patient’s eye and check whether there are any large body vessels that signify the presence of a tumor in the eye. The eye professional may further check the inside of the patient’s eye.
  • Eye ultrasound - This test involves the use of a transducer, a handheld apparatus that produces sound waves. The transducer is positioned on the eyelid or front surface of the eye.
  • Imaging of blood vessels around and in the tumor - This test is called an angiogram. During this procedure, a colored dye is injected in the patient’s blood. The dye travels to the cells in the patient’s eye. A camera detects the movement of the dye and takes pictures every few minutes.
  • Sample testing - The professional will remove a small sample of eye tissue that they suspect is infected and perform a procedure known as a biopsy.
  • Optical coherence tomography - The test takes pictures of parts of the retina and uveal tract.

He/she may take more tests to find out if the tumor has spread. These tests include:

  • Chest X-ray
  • Magnetic resonance imaging (MRI) scan
  • Positron emission tomography (PET) scan
  • Computerized tomography (CT) scan
  • Abdominal ultrasound
  • Blood tests to track liver function
     

Treatment 

Treatment of ocular melanoma is aimed at getting rid of the tumor or preventing it from growing. 

Medical Treatment

The eye doctor may use radiation therapy to kill or prevent the melanoma from growing. The most popular type of radiation treatment is plaque radiation. It involves fixing a radioactive plaque over the tumor. It can be delivered manually or using a machine. This treatment is often delivered over several days. It involves destroying the tumor or hindering its growth through radiation.
Laser treatment may also be used to kill the cancerous cells. The most common form of laser treatment is thermotherapy. This treatment utilizes an infrared laser. This treatment is often used together with radiation treatment.

Surgical Treatment

Surgery involves the removal of the tumor and any tissues surrounding it. For large tumors or tumors affecting the optic nerve, the surgeon will have to do an enucleation (removal of the entire eye). An implant will replace the eye. After the patient has recovered fully, the surgeon will give the patient prosthesis (artificial eye) to replace their natural eye.

Prognosis/Long-term outlook

Complications of ocular melanoma include:

  • Vision loss - Large melanomas cause vision loss and complications like retinal detachment. Small eye melanomas also cause vision loss especially if they are located in sensitive parts of the patient’s eye.
  • Glaucoma - In some cases, patients develop glaucoma. Some of the symptoms of glaucoma include blurry vision, eye redness and eye pain.
  • Spreading of the melanoma - Eye melanoma may spread to areas of the patient’s body including the lungs, liver and bones.
     

Prevention

Experts believe there is a relationship between sunlight exposure and melanomas. Reducing the risk of getting these cancers involves limiting one’s exposure to sunlight, using sunscreen and covering oneself with protective clothing. The American Cancer Society recommends the use of UV protected sunglasses for protection against strong sunlight.