February 4 is During World Cancer Day, so we are taking the opportunity to raise awareness about eye cancers, particularly intraocular melanoma.
When patients hear the term melanoma, they likely often relate it to skin cancers, often caused by sun exposure or other familiar triggers such as smoking. The main difference between this type of skin and eye cancer is the origin of development. Skin melanoma develops from pigment cells called melanocytes. While in the eye, melanoma develops in the uvea, which is the middle layer of the eye (iris, ciliary body and choroid) lying beneath the sclera.
Intraocular Melanoma is said to be the most common primary cancer developing within the globe (the eyeball) of adults, but it is still a rare eye disease. It is considered a primary intraocular cancer, meaning that it is a cancer that starts within the eye itself, and is one of two inner eye cancers, lymphoma being the second.
As with other types of cancers, it is unclear why some people develop them, and others do not. Eye melanomas tend to appear in higher numbers in people with lighter eye colours and those born with certain growths in or on the eyes.
As with most cancers, it is difficult to narrow in on any specific cause. Research suggests eye cancers have both genetic and environmental factors in their development. DNA abnormalities play a significant role in cellular malignant transformation, but analysis is continuously evolving. Exposure to ultraviolet (UV) rays is also a considered cause, which indicates that sun protection is recommended.
Freckles or Nevi, are common inside the eye, and identification of nevi and regular review during eye examination is important, as a small percentage of nevi are actually melanoma in a dormant state.
Due to the development location, that is, growth underneath the surface, melanoma is virtually impossible to detect. It does not cause many significant early symptoms, making visits to an optometrist that much more important.
When symptoms do present themselves, they show up as:
A thorough eye examination is key to establishing what type of melanoma is being handled and how to proceed with treatment. Due to the relatively asymptomatic nature of intraocular melanoma, it is most often caught during routine checkups at the optometrist. This highlights the importance of regular imaging of the retina as part of your eye examination, so that any changes to your retina, including changes to nevi, can be recognized.
Tests will be able to reveal the type of cancer present and determine if the spread is intraocular or secondary. Both classifications present similarly in symptoms.
When a diagnosis is made, an ophthalmologist will recommend how to proceed with treatment depending on the subtype of melanoma present.
Reccomended treatments range from radiation therapy, which is the most common remedy, to surgery, chemotherapy, targeted therapy, drugs, freezing or heat therapy and laser therapy. Each option comes on the recommendation and would be overseen by an eye doctor.
Those who wish pursue other treatment can do so through clinical trials. More information about clinic trails is available from the Canadian Cancer Society, here.
Though rare, intraocular melanoma still affects 5-6 people out of every 1,000,000. With the proper knowledge of symptoms and regular eye exams, it is less likely to do damage and serious harm.
Our team of qualified optometrists will work with you to identify early signs of eyesight problems and suggest effective treatments. Click here to schedule an appointment at your local FYidoctors.