Eye Cancer

What is Eye Cancer?

Eye cancer is a type of cancer that occurs in the eyeball and surrounding structures. The tumors form as a result of the uncontrollable multiplication of abnormal cells in the eye. These tumors can be benign or malignant. Unlike benign tumors, malignant tumors can spread to other parts of the body.

Types of Eye Cancer

The types of eye cancer vary based on the area where the cancer originates, its location, and the type of cells involved.

Retinoblastoma (Eye Cancer in Children)

This type of eye cancer is most commonly seen in children under 5 years old and starts in the retina at the back of the eye. It is considered a malignant tumor.

Uveal Melanoma (The Most Common Eye Cancer in Adults)

Uveal melanoma is the most common type of eye cancer found in adults. It generally appears in the melanocytes of the ciliary body, iris, and choroid. Uveal melanoma is a malignant tumor that is mostly found on the eyelids, but can also appear on the conjunctiva. A significant portion of cases involves individuals over 60 years old.

Conjunctival Cancer

Conjunctival cancer is a rare type of eye cancer found in the eyelids and the white part of the eye. In many cases, the tumor affects the bulbar conjunctiva or the mucous membrane that covers the sclera.

As a type of ocular melanoma, it starts in the melanin-producing cells, which give the eye its color. This cancer is malignant and can be fatal.

Eyelid Tumors

Eyelid cancers occur in tissues near the eyeball. Orbital cancers are found in the nerves and muscles that move the eyeball. Adnexal cancer appears in the supporting tissues, including the eyelids and lacrimal glands.

There are subtypes of eyelid cancer, including:

• Squamous cell carcinoma occurring in the uppermost layer of skin cells.
• Basal cell carcinoma occurring in the uppermost layer of skin cells.
• Rhabdomyosarcoma occurring in the muscle tissue.

Metastatic Eye Cancer

Metastatic eye cancer can present itself as multiple tumors. In women, breast cancer and in men, lung cancer, are common causes of metastatic eye cancer. This type of cancer can affect both eyes.

Causes of Eye Cancer

Like other types of cancer, eye cancer occurs due to the uncontrolled division of cells. Tumors form as a result of the multiplication of cells in the eye. In some cases, parts of the tumor may break off and travel through the blood and lymphatic system, leading to the development of metastatic cancer in other parts of the body.

Symptoms of Eye Cancer

Eye cancer typically does not show symptoms unless it affects the patient’s vision. However, the symptoms observed should not be considered definitive proof of eye cancer. Many benign eye tumors show similar symptoms to other eye conditions and malignant tumors.

The most common symptom of eye cancer is vision loss. Other possible symptoms include:

• Blurred vision
• Partial vision loss
• Total vision loss
• Flashes of light
• Seeing floaters
• Seeing lines
• Protruding eye
• Persistent eye irritation
• A growing spot in the iris over time
• A swelling growing in the eyelid or eyeball
• Changes in the position or movement of the eyeball

Eye cancer is usually detected during an eye exam performed by an ophthalmologist. Signs such as dilated blood vessels or a dark spot in the eye may be considered indicative of eye cancer.

Diagnosis of Eye Cancer

In the diagnosis of eye cancer, in addition to eye examination, many different tests are performed. The methods used for diagnosis include:

Eye Examination

During an eye exam, the doctor looks for signs such as restricted eye movement or enlarged blood vessels. Special examination methods and devices are used for this purpose. These methods include:

• Ophthalmoscope, a handheld device that includes light and multiple lenses to help specialists view the structures at the back of the eyeball.
• Slit-lamp is a device used on a table to provide a detailed view of the front and back of the eyeball. It contains a light source and a microscope.

Imaging

The results from imaging procedures and the eye exam are used together for diagnosis. Commonly used imaging procedures include:

• Ultrasound, a method that uses sound waves to visualize the internal structures of the eyeball. This method helps determine the tumor's location and size. It is commonly used for diagnosing intraocular melanomas.
• Fluorescein angiography, which allows specialists to visualize blood circulation by injecting a special dye into the eye.

If the specialists suspect cancer has spread, additional imaging procedures may be requested. These methods include:

• CT scan
• Chest X-ray
• PET scan
• MRI

Biopsy

A biopsy is a procedure in which a sample is taken from the tumor and examined under a microscope. Eye cancer is usually diagnosed through physical examination, but a biopsy may be used to understand the genetic characteristics of the tumor. Types of biopsy include:

• Fine-needle aspiration biopsy, in which a thin needle is used to remove a sample from the tumor.
• Incisional biopsy, in which a portion of the tumor is removed.
• Excisional biopsy, in which the entire tumor is removed.

Eye Cancer Treatment Methods

For slow-growing tumors or when the diagnosis is uncertain, monitoring the condition may be recommended. Additionally, if the benefits of treatment outweigh its risks, observation may be preferred over immediate treatment.

Laser Therapy and Photodynamic Therapy

Laser therapy is a treatment method that uses heat to destroy eye cancer. The most common type is transpupillary thermotherapy (TTT). During this procedure, infrared light is focused on the tumor, delivering concentrated heat and thereby destroying cancer cells. Laser therapy can be applied alone or after brachytherapy to prevent cancer recurrence.

Radiotherapy (Radiation Therapy)

Radiotherapy is one of the most commonly used treatment methods for eye cancer. It can be applied in two different types. The first type is brachytherapy or internal radiation therapy. It is the most suitable treatment option for eye melanomas. In this treatment, a small disk emitting radiation is placed near the tumor to kill cancer cells.

The second type, external beam radiation therapy (EBRT), involves using a device that does not touch the body to direct radiation to the tumor. Stereotactic surgery is one of the techniques used in which a high dose of radiation is applied to the tumor in a single session. Proton beam radiation therapy is another option, providing targeted high-dose radiation to tumors.

Immunotherapy

Immunotherapy is used to help the patient's immune system detect and destroy cancer cells more effectively. It is especially used for tumors that have spread or are inoperable. It is commonly used for treating uveal melanoma.

Chemotherapy and Targeted Therapies

Chemotherapy is not commonly used for eye cancer, but it may be recommended if the cancer does not respond to other treatments or if it has spread to other areas.

Targeted therapy involves using drugs that target specific weaknesses in cancer cells, destroying them. Targeted treatment is applied when BRAF gene mutations are found in cancer cells. This mutation is commonly found in skin melanomas but can also be used in eye melanomas.

Surgical Intervention and Enucleation (Removal of the Eye)

Surgical intervention is a common treatment for small tumors that have not spread beyond the eyeball. Several procedures are available, including:

Iridectomy

Iridectomy is the removal of part of the iris. Health experts often use this procedure to treat small melanomas.

Iridocyclectomy

Iridocyclectomy involves the removal of part of the iris and ciliary body. This procedure is typically used for treating small melanomas.

Transscleral Resection

Transscleral resection is used to remove melanomas from the choroid or ciliary body.

Enucleation

Enucleation is the removal of the eyeball. This procedure is typically applied for larger tumors or when it is not possible to preserve vision. A prosthetic eye is placed in the socket after the procedure.

Orbital Exenteration

Orbital exenteration involves the removal of the entire eyeball and part of the surrounding tissues. It is applied when cancer has spread to the tissues around the eyeball. A prosthetic eye is placed after the procedure.

Risk Factors for Eye Cancer

Research on eye cancer has identified the following risk factors that may increase the likelihood of developing eye cancer:

Age

Research shows that eye cancer is more common in people over 50. Retinoblastoma, however, occurs in children under 5 years of age.

Skin Color

People with fair and pale skin have a higher risk of developing eye cancer.

Eye Color

People with lighter eye colors are also more likely to develop eye cancer. Though people with brown or dark eyes can also get eye cancer, the risk is lower compared to those with lighter eye colors.

Genetic Factors and Family History

Inherited conditions, such as dysplastic nevus syndrome, which includes multiple atypical moles, can increase the risk of developing certain eye cancers. The BAP1 tumor predisposition syndrome can also increase the risk of developing multiple cancers, including uveal melanoma.

UV Radiation and Sun Exposure

Exposure to UV radiation from the sun or tanning beds increases the risk of melanoma. However, more research is needed on this subject.

Exposure to Chemicals

Exposure to certain chemicals is known to increase the risk of eye cancer. Prolonged exposure to chemicals or even short-term exposure to high amounts can increase the risk.

Eye Trauma and Infections

Trauma or infections in the eye can lead to uncontrolled cell division, potentially leading to cancer.

How to Prevent Eye Cancer

There is no way to prevent eye cancer. However, individuals at high risk for eye cancer should undergo regular eye screenings. For example, those with BAP1 tumor predisposition should not miss their regular checkups.

Life After Eye Cancer

After an eye cancer diagnosis, a patient’s survival rate and quality of life depend on the tumor's location, stage, and whether it has spread. Since many eye cancers are diagnosed early, the chance of successful treatment is quite high.