Eye Cancer: Symptoms, Causes and Types

What is Eye Cancer?

Eye cancer develops in the cells in your eyes and neighbouring structures, such as the tear ducts and eyelids. There are many different types of eye cancer that can impact the eye, with ocular melanoma being the most common, according to the Cancer Council.

What are the Symptoms of Eye Cancer?

The symptoms of eye cancer can include blurred vision, flashes of light, partial or complete loss of vision, floaters, brown or dark spots on the sclera, a bulging eye and eye pain. If you experience any of these symptoms, it is recommended you see a health professional. The symptoms of eye cancer are listed below.

• Blurred Vision: Blurred vision is a common symptom of many conditions, on a rare occasion this can be a symptom of eye cancer and is described as vision that lacks sharpness and detail. Blurry vision from eye cancer may be due to different reasons depending on the type of cancer. For example, a tumour's growth may hinder normal eye function by physically obstructing light, damaging cells, or compressing internal structures.
• Flashes of Light: Flashes of light may contribute as a symptom of eye cancer, depending on the type. Cases such as ocular melanoma or metastatic tumours may potentially cause stress on, detach from or pull on the retina.
• Partial or Complete Loss of Vision: Partial or complete loss of vision can occur as a symptom of eye cancer, depending on the severity and type.
• Floaters: Floaters may be a symptom of eye cancer and are characterised as small specks, wavy lines or shadows in your vision.
• Brown or Dark Spot on the Sclera: A brown or dark spot on the sclera may indicate certain types of eye cancers, such as ocular melanoma. Melanomas develop from melanocytes, which are cells that produce pigment.
• Bulging Eye: A bulging eye may be a symptom of eye cancers, depending on the type of cancer. The bulging may be caused by a growth of a tumour in cases such as ocular melanoma or lymphoma.
• Eye Pain: Eye pain can ensue as a symptom of eye cancer as a result of certain complications, such as increased eye pressure, growth of tumours or inflammation.

What Causes Eye Cancer?

The causes of eye cancer are not completely known by medical professionals. However, there may be certain factors that can increase the likelihood of developing the disease, such as DNA mutations, inherited gene defects, random cell errors, UV light exposure, having light-coloured eyes, fair skin, increasing age and a family history of eye cancer.

What are the Types of Eye Cancer?

The types of eye cancer may include intraocular melanoma (uveal melanoma), retinoblastoma, ocular lymphoma, conjunctival melanoma, eyelid cancer and orbital cancer. The types of eye cancers and their definitions are listed below.

• Intraocular melanoma (uveal melanoma): Intraocular melanoma (uveal melanoma) is a type of rare eye cancer that primarily affects the middle layer of the eye, the uvea.
• Retinoblastoma: Retinoblastoma is an eye cancer that initiates in the retina and may occur more commonly in children.
• Conjunctival Melanoma: Conjunctival melanoma is classified as a rare and aggressive form of eye cancer that affects the surface of the eye.
• Eyelid Cancer: Eyelid cancers, such as basal cell carcinoma, which may be the most common type that can potentially arise from excessive sun exposure, along with other factors.
• Orbital Cancer: Orbital cancer can be characterised as malignant tumours that form in the socket of the eye, known as the orbit.
• Ocular Lymphoma: Ocular melanoma is a form of eye cancer that develops in the white blood cells and is considered rare.

1. Intraocular Melanoma (Uveal Melanoma)

Intraocular melanoma (uveal melanoma) is a type of rare eye cancer that impacts the uvea, which is the middle layer of the eye. This condition ensues in the cells that are responsible for producing pigment in the eye and are called melanocytes. It does not typically cause any early symptoms and is detected through a routine eye exam, according to the National Cancer Institute.

2. Retinoblastoma

Retinoblastoma is considered a rare and aggressive type of eye cancer that mainly occurs in children. This condition may stem from the retina and may include symptoms such as the pupil appearing white in colour instead of red when a light is shone into it, eye redness or pain, an eye that is larger than usual and cloudiness in the iris and pupil.

3. Ocular Lymphoma

Ocular lymphoma is considered a rare type of cancer that develops in the white blood cells of the immune system. Unlike other lymphomas, which usually start in the lymph nodes, ocular lymphoma ensues inside the eye or in neighbouring structures.

4. Conjunctival Melanoma

Conjunctival melanoma is characterised as a rare and aggressive cancer that involves the surface of the eye. According to Butt et al., (2024), conjunctival melanoma was recorded to have a global incidence rate of 1 in a million and is increasing to 1.4; however, this is more prevalent among 65-year-olds.

5. Eyelid Cancer

Eyelid cancer may refer to any form of cancer that develops on the eyelid or in the eyelid. Symptoms of eyelid cancer can include inflammation that persists for a long period, discolouration in the skin of the eyelid and a growth on the eyelid, which may bleed or itch. There are many different types of eyelid cancers, with basal cell carcinoma, sebaceous carcinoma and squamous cell carcinoma being some of the most common forms.

6. Orbital Cancer

Orbital cancer refers to orbital tumours that form within the eye socket (orbit). They may initiate in any of the tissues in the socket, including the blood vessels, nerves, bones and connective tissue. A possible indication of this condition includes a bulging eyeball and accompanying symptoms such as eye pain, swelling, double vision and blurry vision.

How is Eye Cancer Diagnosed?

Eye cancer can be diagnosed through a routine eye test. Optometrists are trained to diagnose a range of eye conditions, including eye cancer, according to Cancer Council Australia. They can direct you to a suitable ophthalmologist for further assessment and treatment. If you are concerned, see your optometrist for comprehensive examination.

How Does Eye Cancer Affect the Retina and Vision Function?

Eye cancer can affect the retina and vision function in different ways depending on the type. However, eye cancers may produce tumours, for example, that can impair how light enters the eye or the eye's ability to process light that enters. The retina is responsible for detecting light and converting it into signals for the brain.

How can Eye Cancer Be Misdiagnosed as Other Eye Problems?

Eye cancer may be misdiagnosed as other problems due to the symptoms that tumours can bring about which can be closely similar to the symptoms of other eye conditions. Additional testing methods by a trained healthcare professional such as imaging technology, ultrasound and high resolution biomicroscopy or fluorescein angiography can assist with completing the right diagnosis of eye cancers instead of other eye problems.

How Can You Protect Your Eyes from Eye Cancer Risks?

You may be able to help protect your eyes from cancer risks by taking more preventative measures. It can be helpful to wear UV protection sunglasses when spending time outdoors in the sun and limiting how much time you spend out in the sun to minimise excessive exposure. However, it is important to note that you may not be able to definitively prevent eye cancer risks, as it is dependent on numerous factors.