Diagnosis of eye cancer

Diagnosis is the process of finding out the cause of a health problem. Diagnosing cancer often means first ruling out other health conditions that share similar symptoms with cancer. It can be a very worrying time for you and your loved ones. Sometimes this process is quick. Sometimes it can feel long and frustrating. But it’s important for doctors to get all the information they need before making a diagnosis of cancer.

Diagnosing eye cancer usually begins with a visit to your family doctor or your optometrist (the eye doctor you see for routine eye exams and glasses or contact lenses). They will ask you about any symptoms you have and do an exam. Based on this information, your doctor may refer you to an ophthalmologist (a medical doctor who specializes in eye diseases) and order tests to check for eye cancer or other health problems.

The following tests are usually used to rule out or diagnose eye cancer. Many of the tests that are used to diagnose cancer are also used to find out the size of the tumour, where the cancer is and if it has spread. Your doctor may also order other tests to check your general health and to help plan your treatment.

Your health history is a record of your symptoms and risks and all the medical events and problems you have had in the past. Your doctor will ask questions about your history of:

• symptoms that suggest eye cancer, such as vision problems
• certain eye conditions that increase the risk for eye cancer, including primary acquired melanosis (PAM) and ocular melanocytosis
• skin or eye moles
• HIV or AIDS
• indoor tanning and spending time in the sun
• welding

Your doctor may also ask about a family history of:

• eye cancer
• risks for eye cancer
• other cancers

A physical exam allows your doctor to look for some signs of eye cancer and metastasis. During a physical exam, your doctor may:

• look at the surface of the eye and tissue around it
• look at the inside of your eye
• feel your neck and abdomen for signs of swelling

Find out more about physical exams.

During an eye exam, an ophthalmologist looks closely at different parts of the eyes for possible signs of cancer. An eye exam checks:

• your vision
• eye movements
• the surface of the eye
• inside the eye, including the retina

As part of an eye exam, you’ll usually have eye drops to make the pupils larger (dilate the pupils). This helps the doctor to see the structures inside the eye better. These eye drops cause changes to your vision, including making your vision blurry. You won’t be able to drive for several hours afterwards while the effects slowly go away.

The ophthalmologist may use several instruments and tests to examine your eye.

An ophthalmoscope is an instrument with a light and magnifying lens. It is used to look through your pupil to examine the back of the eye, including the retina and optic nerve.

A slit lamp is a type of microscope that uses a strong beam of light to examine the inside of the eye through the pupil. It is more powerful than the ophthalmoscope and can give the doctor a more detailed look at the retina and optic nerve. Pictures may be taken of your retina during this part of the exam (called fundus photography).

A gonioscope is a special lens placed on the cornea to examine the area of the eye between the cornea and the iris. It is used to see whether the part of the eye that drains aqueous humour is blocked. The eye is numbed before the gonioscope is placed so you won’t feel the lens.

Tonography is a test to measure the pressure inside the eye. It can be done with an instrument placed on the cornea or a puff of air to the front of the eye.

Optical coherence tomography (OCT) is a type of imaging that uses light waves from a laser to take pictures of the retina and choroid. It takes pictures in segments or “slices.” Together the pictures provide a detailed view of the inside of the eye.

Fundus autofluorescence photography is a type of imaging that uses a special kind of light to make a protein called lipofuscin (also called orange pigment) light up. This protein occurs in uveal melanoma that starts in the choroid.

An ultrasound uses high-frequency sound waves to make images of parts of the body. It is used to diagnose eye cancer and determine features of the tumour such as size and location. An ultrasound of the abdomen may also be used to see if cancer has spread to other parts of the body, like the liver.

Ultrasound biomicroscopy (UBM) is a specialized ultrasound that is sometimes used to get a more detailed view of the eye.

The doctor may use anesthetic eye drops to numb the eyeball before an ultrasound. These drops cause changes to your vision, including making your vision blurry. You won’t be able to drive for several hours afterwards while the effects slowly go away.

Learn more about ultrasounds.

An angiography uses x-rays to look at the blood flow through blood vessels. A fluorescent dye that helps the blood vessels show up more clearly on the x-ray is put into a vein in the arm and travels to the blood vessels in the back of the eye.

Before angiography, the doctor will apply eye drops to make the pupils larger (dilate the pupils). These drops cause changes to your vision, including making your vision blurry. You won’t be able to drive for several hours afterwards while the effects slowly go away.

Find out more about angiography.

Magnetic resonance imaging (MRI) uses powerful magnetic forces and radiofrequency waves to make cross-sectional images of organs, tissues, bones and blood vessels. A computer turns the images into 3D pictures.

An MRI can be used to see if eye cancer has spread to anywhere else in the body.

Find out more about MRIs.

A computed tomography (CT) scan uses special x-ray equipment to make 3D and cross-sectional images of organs, tissues, bones and blood vessels inside the body. A computer turns the images into detailed pictures.

A CT scan can be used to see if eye cancer has spread to anywhere else in the body.

Find out more about CT scans.

During a biopsy, the doctor removes tissues or cells from the body so they can be tested in a lab. A report from a pathologist will show whether or not cancer cells are found in the sample.

A biopsy is not needed to diagnose most eye cancers. Your healthcare team can confirm a cancer diagnosis with only an eye exam and other imagining tests. Because removing tissue from the eye for a biopsy can damage the eye or spread cancer cells, doctors try to avoid using them. You are most likely to have a biopsy if:

• a diagnosis cannot be made with an eye exam and imaging tests
• your doctor thinks you have a certain cancerous tumour of the eye, including conjunctival melanoma, orbital melanoma or lymphoma of the eye
• genetic testing needs to be done on the eye cancer cells to help plan your treatment

Depending on the type of eye cancer you are diagnosed with, you may also have a biopsy of other tissues (for example, bone marrow) to check if the cancer has spread.

During fine needle aspiration (FNA), a very thin needle is used to collect a sample of cells, tissue or fluid from an abnormal area or lump. The sample is then examined under a microscope. Find out more about fine needle aspiration (FNA).

During a surgical biopsy, the doctor makes a cut (incision) to remove tissue from a lump or mass for examination under a microscope. If only some of the cancer is removed, it’s called an incisional biopsy. If all of the cancer is removed, it’s called an excisional biopsy. Tissue that is removed during surgery to treat eye cancer can also be tested in a lab. Find out more about surgical biopsy.

A liquid biopsy is a special kind of biopsy that collects a sample of cancer cells, or parts of cancer cells (for example, pieces of DNA) , from the blood, urine (pee) or other bodily fluid. Most people who have a biopsy for eye cancer will have FNA or surgical biopsy. But liquid biopsy is becoming more common for melanoma of the eye because it has fewer risks than other types of biopsy.

Find out more about biopsies.

Genetic tests look for changes in DNA and proteins that are sometimes found in people who have cancer. Along with other tests, the results of genetic tests can help doctors better understand how cancer cells will behave, predict prognosis and plan treatment for eye cancer. Genetic tests can be done on a sample of cells taken during a biopsy or on tissue removed by surgery.

The types of genetic tests that may be used for eye cancer include:

• cytogenetic tests to analyze the shape, number and arrangement of chromosomes
• gene expression tests to find out which genes are turned on in certain cells

Blood chemistry tests measure certain chemicals in the blood. They show how well certain organs are working and can help find problems. Blood chemistry tests used to stage eye cancer include the following.

A complete blood count (CBC) measures the number and quality of white blood cells, red blood cells and platelets. A CBC is done to check your general health.

Find out more about a complete blood count (CBC).

Liver function tests measure different substances that are made by your liver. These blood tests can tell the healthcare team that there may be a problem with the liver caused by eye cancer that has metastasized. The tests are often called a liver panel because it’s a group of tests that are ordered together.

Albumin is a protein made by the liver. Low levels of albumin may be a sign that the liver is damaged or not working normally.

Alkaline phosphatase (ALP) is an enzyme found in the liver and other tissues in the body. A high level of ALP in the blood may be a sign that the liver is not working normally.

Alanine aminotransferase (ALT) is an enzyme found in the liver and kidneys. A high level of ALT in the blood may signal the liver is not working normally.

Aspartate aminotransferase (AST) is an enzyme found in liver and heart cells. When liver or heart cells are damaged, they release AST into the blood. A high level of AST may be a sign of a problem with the liver.

Gamma-glutamyl transferase (GGT) is an enzyme found in the liver, bile ducts and other tissues in the body. When liver or bile duct cells are damaged, they release GGT into the blood. High levels of GGT may be a sign of a problem with the liver.

Lactate dehydrogenase (LDH) is an enzyme found in the liver and other tissues in the body. It is used by cells when they make energy. A high level of LDH in the blood may be a sign that the liver is damaged or not working normally.

Find out more about blood chemistry tests.

Find out more about a diagnosis. To make the decisions that are right for you, ask your healthcare team questions about diagnosis.