Diagnosing Ocular Melanoma

Ocular melanoma (OM) is usually diagnosed by an optometrist or an ophthalmologist during a routine eye exam, when a doctor looks inside the eye with special lights and instruments.

Ocular melanoma can occur in the iris, the ciliary body or the choroid. OMs in the iris occur in the front, colored part of the eye. Melanomas in the iris usually grow slowly and do not usually metastasize, or spread, to other parts of the body. OMs in the ciliary body and the choroid occur in the back part of the eye and are grouped by the size of the tumor:

  • Small: 1.0-2.5mm in height; greater than 5mm at the base
  • Medium: 2.5-10mm in height; less than or equal to 16mm at the base
  • Large: greater than 10mm in height; greater than 16mm at the base

Often, ocular melanoma is asymptomatic until the tumor grows large enough to create visual disturbances. Only OM of the iris can be diagnosed by external examination. For detection of OM of the choroid or ciliary body, a thorough ophthalmic examination is needed.

What does ocular melanoma look like?

Ocular Melanoma symptoms can vary depending on where the melanoma is. If OM starts in the iris, it may look like a dark spot on the iris or the pupil may become distorted. If it is in the ciliary body or the choroid, a person may have blurry vision, decreased visual acuity, or may have no symptoms, and the cancer may grow before it is noticed.

Surveillance & monitoring:

Currently, there is no consensus regarding type or frequency of scans following diagnosis and treatment of the primary eye tumor. It is important to speak with your doctors to decide what is right for you. The majority of surveillance techniques are focused on the liver. These include: abdominal magnetic resonance imaging (MRI), abdominal ultrasound and liver function tests. The scientific community is currently working to develop guidelines on this topic. You should discuss your options with your doctor.

Other terms 

  • Extraocular extension - The melanoma has spread outside the eye by extending through the wall of the eye
  • Recurrent - Recurrent disease means that the cancer has come back (recurred) after it has been treated.
  • Metastatic Metastatic - melanoma means that the tumor has spread from the eye to distant organs. In ocular melanoma, this means to the liver in about half of all patients.

Do you need more information?

Learn more about the treatment of ocular melanoma, find an ocular melanoma specialist, find ocular melanoma resources or donate directly to CURE OM, the MRF's ocular melanoma initiative.