Eye cancer is rare. In fact, there are only about 3,500 new cases a year, a fraction of the estimated 1.7 million-plus cases of cancer that are diagnosed in the U.S. each year. There are often no early symptoms or warning signs, especially if the cancer is small and not located close to the vital structures of the eye.

Eye cancer is most treatable when it is discovered early, says Renelle Lim, MD, a Yale Medicine ophthalmologist and specialist in ocular oncology and plastic surgery. “For that reason, we always advise everyone to have a dilated eye exam once a year with an eye doctor,” she says.  

The term eye cancer—or ocular cancer—is used to cover a number of malignant conditions that can affect the eyes, including:

• Intraocular (uveal) melanoma: This is the most common cancer that originates in eyes, specifically in the uvea. This is the middle layer of the eye between the white layer at the front of the eye (the sclera) and the retina.
• Intraocular lymphoma: This occurs mostly in older adults. It can develop in the retina or in the jelly-like vitreous. Eye lymphoma usually affects both eyes at the same time. There may be blurred vision, pain, floaters, and sensitivity to light, among other signs.
• Retinoblastoma: This is a very rare childhood cancer. It starts in the cells of the retina, and is usually diagnosed after a doctor or a parent sees that a child’s eye looks unusual. There may be other signs, such as vision problems, or lazy eye (strabismus), in which the eyes appear to be looking in different directions.

The most common cancers affecting the eye actually don’t start there. Instead, these cancers originate elsewhere in the body—especially the breasts and lungs—and spread to the eye, most often to the uvea.

It’s also possible to develop melanoma on the eyelid, but this is considered skin cancer, which has different characteristics than intraocular cancer. About 10% of all skin cancers occur on the eyelids—mostly on the lower lid, which is more likely than the upper lid to be exposed to the sun. Diagnosing and treating these cancers early is also important, as they have the potential to spread and cause significant vision problems.  

The risk for eye cancer increases with age, climbing after the age of 50. Eye cancer occurs more in people with light hair and/or light eyes. Men are at higher risk than women for primary eye cancers—the American Cancer Society estimates that there are about 2,130 men diagnosed with eye cancers annually, compared to 1,410 women.

Some studies suggest that welders have a slightly increased risk of uveal melanoma. Though the cause is not known, it is thought that this may be due to ultraviolet radiation from welding tools, or other environmental causes.

There is no strong evidence that people who have had a lot of sun exposure are at higher risk for eye cancer. However, researchers have discovered a genetic predisposition to eye cancer in patients who have had skin melanoma and other types of cancer.  

An eye doctor will perform a complete eye exam using equipment such as a silt lamp, which emits a narrow, intense beam of light, and an indirect ophthalmoscope, which provides a wide view of the inside of the eye. He or she is looking for a mass in the eye that can be dome-shaped or have a mushroom configuration. It could be elevated or small and flat.  

A specialist may then use multiple imaging modalities to get as much information about the qualities of a tumor as possible. This might include ultrasound to determine the density of the mass, as well as to look at its features and measure its thickness. Optical coherence tomography is an imaging tool that illuminates the retinal layers to assess the subtle presence of fluid, which is a sign of tumor activity. Sometimes magnetic resonance imaging (MRI) can help as well.

In some cases, the doctor will perform a fine needle biopsy to take a small sample of the tumor cells. This will be sent to a cytopathologist (a pathologist who analyzes cells). The cytopathologist will analyze the sample to confirm the diagnosis within a few days.

It’s understandable to feel nervous about having a procedure performed on your eye, but ophthalmologists are often able to make patients comfortable. They numb the eye and use very small, fine instruments, making a procedure like a needle biopsy feel much less invasive than the patient anticipates. “As it turns out, patients actually tolerate eye procedures and eye surgery very well,” Dr. Lim says. 

Tumors on the surface of the eye can be managed by topical chemotherapy, targeted therapy, radiation, or surgical excision. The typical treatment for cancers inside the eye is radiation in the form of brachytherapy. This is most commonly used for uveal melanoma, but it can be used for other eye cancers as well.

Brachytherapy for the eye is delivered by a plaque made of gold, about the size of a quarter, with radioactive seeds on the surface. Radiation oncologists and physicists configure the seeds based on the location and size of the tumor, so that vital surrounding structures will be protected. Each plaque is custom-designed for the patient. Once it is ready, the ophthalmologist surgically applies it onto the surface of the eye, where it emits radiation directly over the tumor.

A patient who has had brachytherapy goes home with a patch over the eye. Once adequate radiation is applied, based on the tumor thickness—typically after a few days—it is surgically removed.  

Though the odds that treatment will be successful depends on the type of eye cancer and its stage of development. There is a 95 to 98% success rate in achieving local control of uveal melanoma when using brachytherapy,” says Dr. Lim.

“Other cases are even simpler. If someone has a tumor on the surface of the eye, like squamous cell carcinoma, we just remove the tumor, and that patient will be free and clear of cancer,” she says. “Of course, the treatment course depends on the extent of involvement and the stage of the tumor at the time of presentation.” 

Eye cancer is difficult to prevent, as researchers are still trying to understand how it develops.    

Yale Medicine has ophthalmologists who can provide comprehensive eye exams. “We recommend that everyone has annual eye exams with an eye doctor, especially if there is a family history of skin cancer,” Dr. Lim says.

Yale Medicine is the only major academic medical center in Connecticut to have a full-time ocular (eye) oncologist. Dr. Lim trained at Wills Eye Hospital in Philadelphia, specializing in ocular oncology and plastic surgery for the eye. At Yale Medicine, she often works with other specialists, including otolaryngologists and neurosurgeons, to surgically remove tumors in a way that protects nearby delicate structures that could affect a patient’s sight.

Dr. Lim often works with other types of specialists to diagnose and treat cancers that originate in other parts of the body and spread to the eye. She also treats patients who need care for eye problems that develop as a result of treatment for cancer in other parts of the body. 

“I work with medical oncologists daily to help patients who are being treated with immunotherapy for other types of cancer. These powerful agents that stimulate the immune response in the body have really changed the treatment paradigm for skin cancer and other types of cancer, including some patients with uveal melanoma,” she says. “But they can have side effects that range from mild dry eye to potential vision loss. Luckily, these side effects are rare, and when we detect them early, we can treat them.”