When we talk about melanoma, the image that spontaneously comes to mind is that of a suspicious mole. Appearance of a new spot, change in shape, color or size of an existing nevus: the signs of this skin cancer are now well known to the general public. And for good reason: melanoma is the most aggressive form of skin cancer, with more than 17,000 new cases diagnosed each year in France. However, what is much less known is that this cancer can develop in a completely unexpected place: the eyes.
Why skin cancer can affect the eye
The skin and the eyes share a fundamental common point: the presence of melanocytes, these cells which produce melanin, the pigment responsible for the color of the skin, hair and iris.
When these cells change abnormally, they can give rise to melanoma, including in the eye.
Thus, melanoma can appear:
- On the eyelids, whose very thin skin is regularly exposed to ultraviolet rays;
- Around the eye;
- But also inside the eyeball itself, in an area devoid of skin.
This is called ocular melanoma, a rare but potentially serious disease.
Ocular melanoma: discreet, but formidable
Each year, 500 to 600 new cases of ocular melanoma are diagnosed in France. The most common is uveal melanoma, which develops in the uvea, the middle layer of the eye. Even rarer, conjunctival melanoma affects the conjunctiva, the transparent tissue that covers the white of the eye.
The main danger of these cancers lies in their clinical silence. In the early stages, they often cause no pain or obvious visual disturbances.
As recalled by Dr Jacqueline Bowen, ophthalmologist and president of the American Association of Optometry in the DailyMail “some of the most serious eye cancers often cause no symptoms in the early or even middle stages.”
This is precisely what makes uveal melanoma so dangerous. Because the retina is a direct extension of the brain, and cancer can spread more easily if it is not detected in time.
Signs too often ignored
Another problem: when symptoms appear, they are frequently trivialized. Blurred vision, difficulty concentrating, flashes of light or dark spots in the visual field… So many signals that many attribute to stress, age or intensive use of screens.
“Many people tend to overlook changes in their vision or the appearance of their eyes“, warns Neil Laird, optometrist, in a previous article. However, these manifestations can reveal a much more serious problem.
Among the signs that should alert you:
- Persistent blurred vision or double vision;
- Flashes of light or dark shapes;
- Dark spots or growths on the iris;
- Redness or irritation that does not go away;
- A swelling or bump around the eye;
- A change in the size or shape of the pupil;
- A progressive loss of peripheral vision.
Who is most at risk for this type of melanoma?
The exact causes of ocular melanoma remain poorly understood. Unlike cutaneous melanoma, its link with UV rays is not clearly established, although some studies suggest a possible role.
However, specialists agree on several risk factors:
- Light eyes (blue, green or gray);
- Clear skin;
- Age, with a peak between 50 and 70 years;
- A family history of eye cancer, which increases the risk by 30 to 50%.
Detect early to save sight… and life
Good news all the same, the prognosis improves considerably when ocular melanoma is detected early. Laser therapies, plate brachytherapy, proton therapy: treatments today make it possible to destroy the tumor while preserving the eye in many cases.
On the other hand, a late diagnosis can lead to extreme situations. “Diagnosed late, these ocular tumors are not only life-threatening, but also visual and aesthetic.”also warned Professor Cassoux, a recognized specialist in eye melanoma in our pages. When the tumor is too large, removal of the eye may become inevitable.
A good argument for monitoring your eyesight, and having a complete ophthalmological examination every one to two years. As Dr. Bowen points out, many eye cancers are discovered during routine exams, even before the first signs appear. This greatly improves the chances of survival.