‌

Nkem Declan is an oncology certified nurse and an adjunct professor in Houston Texas, in the United States of America. She tells ALEXANDER OKERE about the development and symptoms of eye cancer
What is cancer?

Cancer develops when body cells grow out of control, crowding out normal cells. This can start from any place in the body, making it hard for the body to work the way it should.

What is cancer of the eye?

Eye cancer refers to any cancer that starts in any of the different structures of the eye. Melanomas, lymphomas, carcinomas and sarcomas are some of the different types of cancers that can develop from any of the eye structures. Eye melanoma is a type of cancer, and it is the most common. It develops within the eyeball in adults. Most eye melanomas form in the part of the eye that cannot be seen by looking in a mirror.

What causes this type of cancer?

Melanomas arise from body cells called melanocytes, which are the cells that make pigments. When melanoma develops in the eye, it is usually in the uvea, also known as uveal melanomas. The rare form known as conjunctival melanomas can also occur in the conjunctiva.

Are there other types of eye cancer?

Orbital and adnexal cancers are other types of eye cancer in adults. In children, retinoblastoma and medulloepithelioma are two other kinds of cancer that can also occur.

Retinoblastoma is said to be common among children. What puts them at risk of this type of cancer?

Age, heredity and some other factors such as diets low in fruits and vegetables among pregnant mothers, exposure to chemicals in gasoline or diesel in pregnant women are risk factors. Exposure of fathers to radiation, and being born by older fathers have been identified as other risk factors for retinoblastoma.

What are the areas of the eyes that this type of cancer can occur and why are such areas vulnerable?

According to the American Cancer Society, the retina is the most common site for retinoblastoma. A normal pupil (the dark spot in the centre of the eye) looks red when you shine a light in the eye, due to blood vessels in the back of the eye. In an eye with retinoblastoma, the pupil appears rather white or pink, which is known as a white pupillary reflex (or leukocoria).

How is age a risk factor?

Most children diagnosed with retinoblastoma are younger than three years old. Most congenital (heritable) retinoblastomas are found during the first year of life, while non-heritable retinoblastomas tend to be diagnosed in one and two-year-olds. Retinoblastomas are uncommon in children older than six.

Are there human activities that put one at risk of having eye cancer?

Activities such as excessive sun and ultraviolet light exposures, and certain occupations have been shown to increase the risk for eye cancers.

Melanomas are rare in albinos. While there are several studies currently in progress in this regard, existing studies have shown that, perhaps, inherent molecular differences in albino melanocytes interfere with their ability to proliferate. However, melanomas in albinos could go under-recognised as a result of their reduced or absent melanocytic appearance.

What are the symptoms of eye cancer?

According to the American Cancer Society, some of the symptoms of eye cancer include blurry vision or sudden loss or gradual loss of vision, spots or squiggles drifting in the field of vision or flashes of light, visual field loss (losing part of your field of sight), a growing dark spot on the colored part of the eye (iris), change in the size or shape of the pupil, which is the dark spot in the center of the eye. Other symptoms of eye cancer include a change in the position of the eyeball within its socket, bulging of the eye, and change in the way the eye moves within the socket, ulcers on the eyelid, bloody tears or excessive tearing, sudden or gradual loss of eyelashes, and a non-healing sty on the eyelid.

Pain is uncommon, except in situations where the tumour has grown extensively beyond the eye and is pressing down on nerves. The cause of eye cancer is unknown, so it is almost impossible to prevent them. But, generally, a healthy diet, exercise and lifestyle modification, such as not smoking or drinking alcohol can help maintain a good immune system, thereby preventing cancer.

When is surgery required and are there risks or side effects?

Most of the time, surgery is indicated for cancers that are localised and have not spread to a distant location. Surgery on the eye can lead to the loss of some or all of the vision in that eye. Surgical procedures, like the removal of the eyeball (enucleation) and orbital exenteration, result in immediate and complete vision loss in the eye. Other eye surgeries can lead to vision loss in the future, although in some cases, vision may have already been damaged or lost because of the cancer. Enucleation can affect an individual’s physical appearance.

In what ways can a person take care of their eyes to avoid health challenges like cancer?

The American Cancer Society recommends wearing UV-protected sunglasses when outside in strong sunlight. The link between sunlight and eye melanomas is not proven, but some doctors think that sunglasses might also reduce eye melanoma risk.

Are there fruits and vegetables that can help?

Fruits and vegetables have some generally known health benefits. Studies have suggested that there is a lower risk of cancer among people who eat meals that are rich in fruits and vegetables. Also, Jed W. Fahey, ScD, MS, an assistant professor at Johns Hopkins Bloomberg School of Public Health and its School of Medicine, has suggested that a variety of chemicals from plants known as phytochemicals seem to protect cells from harmful compounds in food and in the environment, while also preventing cell damage and mutations.