What Is Eye Cancer?

Eye cancer refers to any cancer that affects the eye. Cancers of the eye are categorized by where the cancer begins: Intraocular cancer is found in the eyeball itself, while orbital and adnexal cancers are found in the tissue and structures surrounding the eye. Symptoms vary depending on which part of the eye is affected and the type of cancer involved. It’s possible for eye cancer to spread to other areas through metastasis.

The eye has three major parts: the eyeball (globe), which is mostly filled with a jelly-like material called the vitreous, the orbit, which refer to the tissues surrounding the eyeball, and the adnexal (accessory) structures such as the eyelids and tear glands.

Within intraocular cancer, there are two more classifications: Cancers that start in the eye are called primary intraocular cancers, and secondary intraocular cancers if they start somewhere else and spread to the eye.

Types

Uveal Melanoma

This is the most common primary intraocular eye cancer in adults. It accounts for about 5% of all melanoma cases. The uvea is the middle layer of the eye, and consists of the iris (the colored part of the eye (most often blue or brown). It surrounds the pupil, the small opening where light enters the eyeball), choroid (a thin, pigmented layer lining the eyeball that nourishes the retina and the front of the eye with blood), and ciliary body (the muscles inside the eye that change the shape of the lens so that the eye can focus on near or distant objects). About nine out of 10 cases of this cancer forms in the choroid or the ciliary body.

Uveal melanoma may have no symptoms, and some cases are found during routine eye exams. If there are symptoms, they may include vision changes, flashing lights, a dark spot on the iris, a change in the shape of the pupil, glaucoma, and, rarely, eye pain or redness.This type of melanoma can be there for a long time before beginning to grow. When they do, they are slow-growing and generally have a good prognosis. Uveal melanomas can spread through the blood and commonly spread to the liver. 

Ocular Lymphoma

There are two types of ocular lymphoma: mucosa-associated lymphoid tissue lymphoma (MALT) and orbital lymphoma. MALT occurs on the surface covering of the eye and the inside layer of eyelid known as the conjunctiva and is a type of non-Hodgkin’s B cell lymphoma. It usually shows up as a salmon-colored or light orange growth on the surface of the eye.

Orbital lymphoma is the most common type of cancer of the orbit in adults. It is also a form of B-cell non-Hodgkin lymphoma. It may show up as a nodule in the eyelid or around the eye, or in the lacrimal gland and the orbit. It may also cause the eye to be pushed out. This type of cancer usually does not cause pain.

Retinoblastoma

This type of eye cancer primarily affects young children. It is a cancer of the retina, a light-sensitive layer of tissue in the eye, and accounts for accounts for 3% of cancers in children. It is caused by a genetic mutation that begins in the retina of the eye. The retina nerve cells are abnormal, and begin to grow and spread quickly.

Conjunctival Cancers

The most common form of conjunctival cancer is squamous cell carcinoma. It can affect the area around the cornea on the eye surface or the inner conjunctival layer of the eyelids. It has a very low risk of spreading to the lymph nodes. If this cancer becomes aggressive, the eye and eye socket may have to be removed.

Melanoma can also occur on the conjunctiva. Conjunctival melanomas can spread to the lymph nodes and other parts of the body. This risk is higher for thicker melanomas.

Orbital Sarcoma

The most common sarcoma in the orbit is rhabdomyosarcoma, which is commonly found in children.

Eyelid Cancers

More than 90% of eyelid cancers are basal cell carcinomas. The lower eyelids are involved in more than 70% of cases, followed by the inner corner of the eye, upper eyelid and the outside corner of the eye. This cancer is usually not aggressive and does not spread to lymph nodes or distant organs.

Squamous cell carcinoma can also affect the eyelids. While it's less common compared with basal cell carcinoma, it is more aggressive. It can spread to nearby lymph nodes and other parts of the body.

Melanoma is another form of eyelid cancer, but it's the rarest and accounts for 1% of all eyelid cancers. It can spread to distant organs like the lungs, liver, or brain, where the cancer can become life-threatening.

Eye Cancer Symptoms

Symptoms that accompany eye cancer can be difficult to pinpoint since they are similar to those of other eye conditions. This makes early detection of eye cancers somewhat difficult. Some of the symptoms you may experience with eye cancers include:

• Blurry vision
• Sudden loss of vision
• Spots in your field of vision, or floaters
• Flashes of light
• A dark spot that grows in size on the iris
• Change in the size or shape of your pupil
• A change in the orientation or positioning of the eyeball
• Eye bulging
• Changes in the way the eye moves within the socket
• Eye pain
• Changes in how the eyes appear in photos (a pupil that appears light instead of dark)

Causes

The cause of eye cancer is not clear. Some think that eye cancers are genetic or caused during embryonic development. Many cancers are believed to be caused by changes to DNA brought on by various risk factors and environmental influences. Eye cancer is also associated with other eye conditions.

Risk factors of eye cancer include:

• Being Caucasian
• Having light-colored eyes
• Age
• Being male
• Abnormal moles on the skin
• BAP1 cancer syndrome
• Family history
• Sun exposure

Diagnosis

Diagnosing eye cancer can be difficult because its symptoms mimic those of other eye conditions. Typically, cancers of the eye are detected during routine vision screenings. People with known genetic traits or conditions that increase their risk of developing eye cancers may undergo additional genetic screenings.

Your ophthalmologist will perform the following exams to tests to diagnose eye cancer:

• Ophthalmologic examination: Your ophthalmologist may use an opthalmoscope, a handheld device that provides light and magnification, to examine your eye. They may also use an indirect opothalmoscope, or a slit lamp, which sits on a platform and provides stronger magnification to see into your eye. A gonioscopy lens may also help them take a better look at your eye. This mirrored lens is placed on the cornea and can be used to see tumor growth in the eye
• Eye and orbital ultrasound: Ultrasounds use sound waves to help your healthcare provider visualize internal structures, and can be particularly useful for diagnosing melanomas of the eye. Ultrasound biomicroscopy is a special type of ultrasound that uses high-energy waves to show a detailed view of the front of the eye
• Optical coherence tomography: This type of imaging uses light waves to take cross-section pictures of your retina. Your ophthalmologist can see each of the retina’s distinctive layers, which helps them map and measure the thickness of these layers. These measurements help with diagnosis
• Fluorescein angiography: Your ophthalmologist uses a special camera to take pictures of your retina during this imaging test. These pictures help your ophthalmologist get a better look at the blood vessels and other structures in the back of the eye
• Biopsy: The types of biopsy used to diagnose eye cancer include fine needle aspiration, excisional biopsy, and incisional biopsy. Fine needle aspiration uses a very thin, hollow needle attached to a syringe to take out a small amount of fluid and very small pieces of tissue from the tumor. Excisional biopsy is where a surgeon cuts through the skin to remove the entire tumor, while incisional biopsy is where a small part of a large tumor is extracted. These two types of biopsy are often done using local or regional anesthesia
• Liquid biopsy: This is a test done on a sample of blood to look for pieces of DNA from tumor cells that are in the blood. A liquid biopsy may be used to help find cancer at an early stage

Staging

A staging system is a standard way to describe how far a cancer has spread. The most common systems used to describe the stages of eye cancer are the American Joint Committee on Cancer (AJCC) TNM system and the Collaborative Ocular Melanoma Study (COMS) group classification system.

The AJCC TNM system is based on three key pieces of information:

• The size and extent of the main tumor (T)
• The spread to nearby lymph nodes (N)
• The spread (metastasis) to distant sites (M)

The staging system devised by the COMS group is simpler, and divides eye melanomas into small, medium, and large:

• Small: Between 1 mm and 3 mm in height and between 5 mm and 16 mm across
• Medium: Between 3.1 mm and 8 mm in height and no more than 16 mm across
• Large: More than 8 mm in height or more than 16 mm across

Treatment

Treatments for eye cancer depend a lot on the size and stage of your cancer, where it is located, and how fast the cancer is growing. Some cancers grow very slowly and rarely spread. In these cases, your healthcare provider may choose to monitor the cancer closely without performing any invasive procedures.

When more significant treatment is needed, options include:

• Surgery can remove small parts of, or even the entire eye
• Radiation therapy using implanted seeds or external radiation beams can target and destroy cancer cells
• Laser therapy using infrared beams can heat or burn cancerous tissue
• Chemotherapy is not often used in eye cancers unless it has spread to other parts of the body
• Immunotherapy and other targeted treatments have become very effective at training the immune system or managing genetic mutations to fight eye cancers

The focus of treatment is on preserving vision, so a small cancer that is already impacting vision could lead to complete removal of the eye. In other cases, a large area of cancer that is not impacting vision may be treated without removing the eye. Treatment choices should be a shared decision between you and your healthcare provider.

Coping

Cancer can be a scary diagnosis, no matter what part of the body is affected. One of the most common issues, even after a successful cancer treatment, is the fear that your cancer will return. Ask your healthcare provider about follow-up care and screening, as well as local support groups and organizations.

So far, no dietary supplements (including vitamins, minerals, and herbal products) have been shown to clearly help lower the risk of eye cancer progressing or coming back. This doesn’t mean that no supplements will help. If you’re thinking about taking any type of nutritional supplement, talk to your healthcare team. They can help you decide which ones you can use safely while avoiding those that might be harmful.

Eye cancer survivors may benefit from joining a support group of others who have had the same type of cancer or share their experiences. Surrounding yourself with a support network can also help you cope with anxiety and stress.

A Word From Verywell

Eye cancer can grow undetected for some time, but most forms of eye cancer are relatively rare. In many cases, cancers of the eye do not spread to other parts of the body. Decisions about treatment aren’t usually based on whether the cancer is spreading, but on how much the cancer impacts your vision and quality of life. Being diagnosed with cancer and going through cancer treatments can be stressful. Be sure to talk to friends and family or seek support through a community of people who understand what you are going through.