Cancer starts when cells in the body begin to grow out of control. Cells in nearly any part of the body can become cancer, and can spread to other areas of the body. An eye cancer starts in the eye. There are different types of eye cancers. To understand eye cancers, it helps to know something about the parts of the eye and what they do.
Cancers in the eye (intraocular cancers)
Two types of cancers can be found in the eye. Primary intraocular cancers start inside the eyeball. In adults, melanoma is the most common primary intraocular cancer, followed by primary intraocular lymphoma. These 2 cancers are the focus of this document.
In children, retinoblastoma (a cancer that starts in cells in the retina) is the most common primary intraocular cancer, and medulloepithelioma is the next most common (but is still extremely rare). These childhood cancers are discussed in Retinoblastoma.
Secondary intraocular cancers start somewhere else in the body and then spread to the eye. These are not truly “eye cancers,” but they are actually more common than primary intraocular cancers. The most common cancers that spread to the eye are breast and lung cancers. Most often these cancers spread to the part of the eyeball called the uvea. For more information on these types of cancers, see our documents on them.
Intraocular melanoma (melanoma of the eye)
Intraocular melanoma is the most common type of cancer that develops within the eyeball in adults, but it is still fairly rare. Melanomas of the skin are much more common than intraocular melanomas.
Melanomas develop from pigment-making cells called melanocytes. When melanoma develops in the eye, it is usually in the uvea, which is why these cancers are also called uveal melanomas.
About 9 out of 10 intraocular melanomas develop in the choroid or ciliary body (which are parts of the uvea). Choroid cells make the same kind of pigment as melanocytes in the skin, so it’s not surprising that these cells sometimes form melanomas.
Most of the other intraocular melanomas start in the iris (also part of the uvea). These are the easiest for a person (or their doctor) to see because they often start in a dark spot on the iris that has been present for many years and then begins to grow. These melanomas usually are fairly slow growing, and they rarely spread to other parts of the body. For these reasons, people with iris melanomas generally have a good prognosis (outlook).
Intraocular melanomas are generally made up of 2 different kinds of cells.
- Spindle cells: These are long, thin cells.
- Epithelioid cells: These cells are almost round but with some straight edges.
Primary intraocular lymphoma (lymphoma of the eye)
Lymphoma is a type of cancer that starts in immune system cells called lymphocytes. Most lymphomas start in lymph nodes, which are bean-sized collections of immune system cells scattered throughout the body. Lymphomas can also start in internal organs such as the stomach, lungs, and rarely, in the eyes.
Orbital and adnexal cancers
Cancers of the orbit and adnexa develop from tissues such as muscle, nerve, and skin around the eyeball and are like their counterparts in other parts of the body. These are described in our other documents on cancers of muscle, nerve, skin, etc. For example, cancers of the eyelid are usually skin cancers, which are described in our documents on skin cancers ( Melanoma Skin Cancer and Skin Cancer: Basal and Squamous Cell). Muscle cancer is described in Rhabdomyosarcoma.
Certain risk factors that are associated with eye cancers
1. Risk factors associated with Intraocular melanoma
Intraocular melanoma is the commonest form of eye cancer. The commonly associated risk factors of this type of eye cancer are :
- Race or ethnicity – Caucasians or whites are at a higher risk of melanomas than African Americans or Asian Americans. Whites are also at a higher risk of skin melanomas. Eye melanomas follow a similar pattern in terms of risk association.
- Age – Primary intraocular melanoma commonly occurs after the age of 50. It is rare in children and those who are over 70 years of age.
- Sex – Eye melanoma affects both men and women with same frequency.
- Colors of the eyes or iris – Those with light colored eyes have raised risk of intraocular melanoma. Among those blue, grey or green or any light eyed individuals are at higher risk than brown eyed individuals. The actual reason is unknown but it is speculated that the risk assessment is similar to whites being more prone to skin and eye melanomas.
- Sun exposure – Too much sun exposure or exposure to ultraviolet (UV) rays (either from the sun or tanning beds) raises risk of skin melanomas. This is true especially in Caucasians and whites. There is no evidence however that this is true for eye melanomas but concerns that similar association might be true for eye melanomas.
- Inherited conditions – Those with conditions like dysplastic nevus syndrome are at a higher risk of eye melanomas. These individuals have over 100 abnormal shaped and sized moles over their skin. Those with abnormal brown spots on the uvea called nevus of Ota are also at risk of getting eye melanomas. Nevi or moles around or within the eye also raise the risk of eye melanomas. Individuals with brown spots over the uvea in a condition called oculodermal melanocytosis are at a higher risk of eye melanomas as well. Eye melanomas may also be inherited and may run in some families.
- Occupational hazards – Workers like farmers, fishermen, welders, or chemical and laundry workers have a greater risk of getting eye melanomas.
2. Risk factors associated with other types of eye cancer
- People with weakened or suppressed immune system like those with acquired immunodeficiency syndrome (AIDS), those on anti-rejection drugs after an organ transplant or elderly are at greater risk of primary intraocular lymphoma. Sometimes the risk of eye lymphoma is raised by infection with a bacteria called Chlamydophila psittaci. The bacteria is caught from infected domestic animals such as cats and birds. This leads lung infections and conjunctival inflammation or conjunctivitis. This bacteria is associated with adnexal malt lymphoma.
- Risk of squamous cell cancer of the eyes also rises with depressed immunity. Those with HIV AIDS infection and on drugs that suppress the immunity are at higher risks. Sometimes Human papilloma virus (HPV) may infect the eye causing squamous cell carcinoma of the eye. This virus is related to cancers of the cervix and mouth. Exposure to sun and UV rays also raises risk of this type of eye cancer.
- Kaposi sarcoma of the eye occurs more commonly in people with HIV or AIDS. This tumor is rare.
- Retinoblastoma – This type of eye cancer affects young children. The risk of this disease is carried in a faulty gene. This disease thus is inherited and leads to loss of vision or even death of the child if not detected and treated early.
Treatment Options Of Eye Cancer
1. Treatment overview
Many people with intraocular melanoma are treated by more than one specialist with more than one type of treatment. This is called a multidisciplinary team approach. For example, patients who receive radiation therapy to the eye may need to also talk with an ophthalmologist or plastic surgeon to make sure the eye can still function after treatment.
Cancer care teams also include a variety of other health care professionals, including physician assistants, oncology nurses, social workers, pharmacists, counselors, dietitians, and others.
Patients should have a sense that their doctors have a coordinated plan of care and are communicating effectively with one another. If patients do not feel that the team is communicating effectively with them or each other about the goals of treatment and the plan of care, patients should discuss this with their doctors or seek additional opinions before treatment.
Descriptions of the most common treatment options for eye cancer are listed below. Treatment options and recommendations depend on several factors, including the type and stage of cancer, possible side effects, and the patient’s preferences and overall health. Your care plan may also include treatment for symptoms and side effects, an important part of cancer care.
2. Active surveillance/observation
The doctor may recommend this approach if the intraocular melanoma is small or slow-growing and/or if treating the cancer would cause more discomfort than the disease itself. For example, this approach may be appropriate for people without any symptoms, older or seriously ill people, or people with a tumor in their only useful eye.
The patient is monitored closely, and active treatment begins if the tumor shows signs of becoming more aggressive or spreading. This approach may also be called observation, watchful waiting, or watch-and-wait. If the tumor grows bigger than 10 mm in diameter or 2 mm to 3 mm in height (thickness), then the doctor and the patient may decide to proceed with active treatment.
Surgery is the removal of the tumor and some surrounding healthy tissue during an operation. This is also called surgical resection. Eye surgery is typically performed by an ophthalmologist. Surgery to the eye is quite common in the treatment of intraocular melanoma. During surgery, the ophthalmologist will remove parts or all of the affected eye depending on the size and spread of the tumor.
Surgical options include:
- Iridectomy: Removal of part of the iris
- Iridocyclectomy: Removal of part of the iris and ciliary body
- Sclerouvectomy/endoresection: Surgery to remove the choroidal tumor while keeping the eye
- Enucleation: Removal of the eye
In some cases, surgery may also be used to place a radioactive disc for internal radiation therapy, also called brachytherapy. More information about radiation therapy is below.
4. Having an eye removed
Sometimes the only choice a doctor has in treating intraocular melanoma is to remove the eye. Because of this visual loss, a person with one eye may have trouble with depth perception. Most people adjust to these differences.
Many people worry about what they will look like when they have an eye removed. The cosmetic surgery available today usually yields good cosmetic results. To fill the area left by the missing eye, the person is fitted for a prosthesis (artificial eye). The prosthesis will look and behave almost the same as a natural eye. For example, the artificial eye will move along with the person’s remaining eye, just not as much as a natural eye moves. Family members may be able to tell that the eye is not real, but it is unlikely that strangers will know.
5. Radiation therapy
Radiation therapy is the use of high-energy x-rays or other particles to destroy cancer cells. A doctor who specializes in giving radiation therapy to treat cancer is a radiation oncologist. A radiation therapy regimen (schedule) usually consists of a specific number of treatments given over a set period of time.
Radiation therapy may result in a variety of side effects, so it is important to talk with your ophthalmologist about what to expect. The extent of side effects depends on the type and dose of radiation therapy the person receives, where the tumor is located, and the patient’s general health. For larger tumors, there is more risk for side effects or complications from radiation therapy. The side effects may not show up right away. So let your doctor know is a problem arises. Be sure to ask what problems and signs to watch out for after being treated with radiation therapy.
Common side effects include:
- Cataracts. A cataract is when the lens of the eye becomes cloudy. People with cataracts may have cloudy or foggy vision, have trouble seeing at night, or have problems with glare from the sun or bright lights. If the cataract is causing major problems with a person’s eyesight, it may be surgically removed.
- Loss of eyelashes and/or a dry eye. These side effects can occur with external-beam radiation therapy and proton-beam radiation therapy.
The following side effects are less common and can cause a loss of vision:
- Radiation retinopathy: The development of abnormal blood vessels in the retina
- Radiation optic neuropathy: Optic nerve damage
- Neovascular glaucoma: A painful condition where new blood vessels develop and block the outflow of fluid from the eye
- Loss of eye: If there is significant damage to the eye from radiation therapy, the eye may need to be removed.
6. Laser therapy
This procedure uses heat in the form of a laser to shrink a smaller tumor. It may also be called thermotherapy or transpupillary thermotherapy (TTT). This treatment potentially has fewer side effects than surgery or radiation therapy. Laser therapy may also be combined with radiation therapy.
Can Eye Cancer Be Prevented?
We do not yet know what causes most cancers of the eye, so it is not yet possible to prevent them.
1. Eye melanoma
We know there is a link between sunlight and melanomas of the skin, and there are things you can do that might reduce your risk of these cancers, including limiting your exposure to intense sunlight, covering up with protective hats and clothing, and using sunscreen.
The American Cancer Society also recommends wearing UV-protected sunglasses when outside in strong sunlight. Wrap-around sunglasses with 99% to 100% UVA and UVB absorption provide the best protection for the eyes and the surrounding skin. This might help reduce the risk of developing cancers of the skin around the eyes. The link between sunlight and eye melanomas is not proven, but some doctors think that sunglasses might also reduce eye melanoma risk.
2. Eye lymphoma
Many people with eye lymphoma have no clear risk factors for this disease. For now, the best way to limit the risk of eye lymphoma is to try to avoid infection with HIV, the virus that causes AIDS.