Eye Cancer - Causes, Types, Symptoms, Prevention, Diagnosis, and Treatment

What Is an Eye Cancer?

Eye cancer is cancer that starts in various parts of the eye. It occurs when the healthy cells in the eye begin to change and grow out of control. Eye melanoma is a common type of eye cancer.

Where Does Eye Cancer Start in the Eye?

The eye has three major parts, which are:

1. Eyeball (globe), often filled with a jelly-like material called vitreous humor and has three main layers (the uvea, the sclera, and the retina), which is the outer part of the eye. The retina is the thin-layered structure overlaying the eyeball, which sends information to the brain from the eye. The uvea nourishes the eyeball, and it consists of three parts of the iris, ciliary body, and choroid.

2. The orbit (is the bony cup enclosing the eye).

3. The adnexal or accessory structures such as the tear glands and the eyelids.

Cancers, when it originates in the eye itself, it is called primary intraocular cancer. The most common type of eye cancer is uvea metastasis. Cancer that spreads from the other parts of the body to the uvea is called secondary cancer.

What Are the Types of Eye Cancer?

The types of eye cancer are:

• Ciliary body melanoma.

• Choroidal melanoma.

• Iris melanoma.

• Intraocular melanoma.

• Retinoblastoma.

• Hemangioma.

• Conjunctival melanoma.

• Eyelid carcinoma.

• Lacrimal gland tumor.

What Causes Eye Cancer?

The DNA (Deoxyribonucleic acid) is a chemical in the cells which form up the genes. DNA is also the hereditary material in the human and other organisms. The DNA helps replicate DNA, hence increasing the number of chromosomes and cells, the formation of RNA from DNA, and the transfer of genetic information from parents to offspring. This DNA will instruct the cells on their function. When there is an error or defect in the DNA, the cells will start to grow and divide abnormally.

What Are the Risk Factors for Eye Cancer?

The risk factor is any factor that increases the risk of getting a particular disease. Risk factors like smoking and chewing tobacco can be changed, but risk factors like family history and patient's age cannot be changed. But having a risk factor or more risk factor does not mean that a person will get cancer, and the patient who has the disease may have few or no risk factors.

• Race or ethnicity: The risk of getting melanoma is higher in whites than in African Americans and Asian Americans.

• Eye color: Light-colored eye people are at a higher risk for uveal melanoma than people with dark eyes and skin.

• Gender or Age: Eye melanoma can occur at any age, but older people are at high risk, and it more commonly occurs in men than in women.

• Moles: Various types of moles (nevi) in the eye or on the skin have been associated with a high risk of uveal eye melanoma. These include giant choroidal, choroidal, and iris nevi. On the skin, atypical nevi, which is the common nevi of the skin, and freckles. Conjunctival melanoma can occur due to an eye condition called primary acquired melanosis (PAM), where there are too many melanocytes.

• Family History: Uveal eye melanomas can occur due to family history in an individual.

• Unproven risk factors: These are sun exposure, skin melanoma, and certain occupations.

• Inherited conditions:

1. People with dysplastic nevus syndrome having many irregular moles on the skin are at increased risk of skin melanoma. They also have a higher risk of forming melanoma of the eye.

2. People with unusual brown spots on the uvea (known as nevus of Ota or oculodermal melanocytosis) also have an increased chance of acquiring uveal eye melanoma.

3. BAP1 cancer syndrome is an uncommon inherited condition in which family members are at high risk for uveal eye melanoma and melanoma of the skin, kidney cancer, malignant mesothelioma, etc.

What Are the Signs and Symptoms of Eye Cancer?

The common signs of eye cancer are:

• Flashes of light, shadows, or wiggly lines in the vision.

• Eye floaters.

• A dark patch in the eye that is getting bigger.

• Blurred vision.

• Change in the color of the iris.

• Partial or complete loss of sight.

• Bulging of one eye.

• A lump in the eyelid or in the eye that is growing in size.

• Pain in or around the eye, which is rare.

How to Diagnose Eye Cancer?

1. Eye examination:

• Direct ophthalmoscope.

• Indirect ophthalmoscope.

• Gonioscopy lens.

2. Imaging tests:

• Ultrasound Biomicroscopy (UBM).

• Optical coherence tomography (OCT).

• Fluorescein angiography.

• Chest x-ray.

• Computed tomography (CT).

• Magnetic resonance imaging (MRI).

3. Biopsy:

• Fine needle aspiration biopsy.

• Excisional or incisional biopsy.

• Fine needle biopsy of the tumor.

• Liquid biopsy.

4. Blood tests:

• Liver function test.

How to Prevent Eye Cancer?

The following methods can prevent eye cancer:

• Avoiding exposure to direct sunlight.

• Using UV-protected sunglasses that wrap around the eye.

• Using sunglasses that block ultraviolet rays.

• By treating eye injury as soon as possible to prevent eye cancer.

How to Treat Eye Cancer?

The treatment of eye cancer depends on the following factor:

• The size and location of the tumor in the eye.

• The type of eye cancer.

• Whether cancer has spread outside of the eye or not.

• The effect the treatment will have on your vision

• Patient's age and general health.

• Personal preferences.

The main goal of treatment is to reduce the spread of cancer and to save the vision whenever it is possible. Depending on cancer, the treatment options are as follows:

1. Radiation therapy: Radiation therapy is the most common treatment for eye cancer. It can be used before or after surgery as the main treatment. The types of radiation therapy used are brachytherapy or external beam radiation therapy.

2. Surgery: Surgery is another standard treatment for eye cancer. It can be used depending upon the cancer size and stage. Surgical options to treat eye cancer are:

• Enucleation: Removal of the eye.

• Iridectomy: Elimination of part of the iris.

• Iridocyclectomy: Elimination of part of the iris and the ciliary body.

• Sclerouvectomy or Endoresection: Surgery to eliminate the choroidal tumor while preserving the eye.

• Orbital Exenteration: It is the surgical extraction of the eyeball and the neighboring tissues, including the eyelids and the muscles, nerves, and fatty tissue adjacent to the eye.

• Laser surgery: Transpupillary thermotherapy and laser photocoagulation are the laser surgery techniques used to treat eye cancer where infrared light and high-energy light beams are used to burn and kill the tumor cells.

• Reconstructive Surgery: It is done to promote eye function or to enhance appearance.

3. Chemotherapy: Drugs are used to treat melanoma of the eye.

4. Targeted therapy: These drugs target specific molecules such as proteins inside cancer cells to arrest cancer growth and spread. This method is used to treat eye cancer.

5. Immunotherapy: This is the method that uses the immune system to destroy the cancer cells. Interferon alfa-2b (Intron A) is an immunotherapy drug used to treat cancer of the lymphoma or the eyelid.