Tests for eye cancer (ocular melanoma)

You may have tests to diagnose eye cancer (ocular melanoma), to help plan your treatment or to check how effective it has been.

Tests to diagnose eye cancer

If you have symptoms of eye cancer, you usually start by seeing your optician or GP. If they are unsure what the problem is, they will refer you to see a specialist at the hospital. A specialist eye doctor is called an ophthalmologist.

At the hospital, the ophthalmologist will examine you. The doctor may put eye drops in your eye before or during some tests. This widens (dilates) the black part in the middle of your eye (your pupil). This makes it easier to for the specialist to check your eyes. The drops make your eyesight blurry for a few hours, and you might find bright lights uncomfortable.

Do not drive until your eyesight returns to normal.

You may have some of the following tests.

Examining your eye

The doctor looks at the inside of your eye using a small, handheld lens and light (ophthalmoscope). Or they may ask you to look into a large microscope that sits on a table. They may put eye drops in your eye to widen your pupil.

Ultrasound scan

An ultrasound scan uses sound waves to build up a picture on a computer screen of the inside of your eye and nearby areas. The doctor gently presses a small probe against your closed eyelid and moves it over the skin. This is painless and usually only takes a few minutes.

Fluorescein angiography

The doctor uses this test to examine the back of your eye. They put eye drops in your eye to widen your pupil. They also inject a dye, called fluorescein, into a vein in your arm. The doctor uses a special camera to take photos of the dye as it moves through the blood vessels at the back of your eye.

You may feel warm or flushed for a short time after the injection. After the test, your urine will be bright yellow, and your skin may be slightly yellow. This is caused by the dye. It is harmless and only lasts a few days.


Doctors can often diagnose eye melanoma by looking inside the eye and using the tests we have explained above. But you may need to have a small piece of tissue or cells (biopsy) removed from the eye. You are more likely to have a biopsy if your specialist thinks you may have a conjunctival melanoma.

A biopsy is only done by expert eye doctors, who can do it quickly and without causing you pain. They use a very fine needle. You can have the test with a local anaesthetic, or sometimes with a general anaesthetic.

The tissue is sent to a laboratory to be looked at by a pathologist (a doctor who specialises in studying cells). The pathologist looks at the tissue under a microscope to check for cancer cells. They also check for conditions that may develop into melanoma if left untreated.

Further tests for eye melanoma

You may have other tests to help plan your treatment, or to check how effective treatment has been.


If you need surgery, this test shows exactly where the melanoma is and helps the doctor plan the operation. The doctor turns down the lights in the room and shines a very bright light into your eye to look for abnormal areas.

Colour fundus photography

This test may be used to show what the tumour looks like before and after a treatment, such as radiotherapy. The doctor gives you eye drops to widen your pupil. They use a special camera to take photographs of the back of your eye (fundus).

PET-CT scan

A PET-CT scan is a combination of a CT (computerised tomography) scan, which takes a series of x-rays to build up a three-dimensional picture, and a PET (positron emission tomography) scan.

MRI scan

An MRI scan uses magnetism to build up a detailed picture of areas of your body. You may be given an injection of dye into a vein to improve the images from the scan. This test is painless and takes around 30 minutes.