How is ocular (uveal) melanoma diagnosed?

Ophthalmoscopy (funduscopy) – a test that allows your doctor to look at the inside of your eye to check for abnormalities. You may be asked to look into a large microscope that sits on a table (a slit lamp examination). The doctor may put eye drops in your eye to widen (dilate) your pupil. This will allow the doctor to see inside your eye, so they may not have to perform a biopsy to determine if a tumour is present. The eye drops make your eyesight blurry for a few hours and you might find bright light uncomfortable, so take sunglasses to your appointment. You cannot drive until your eyesight returns to normal.

Colour fundus photography – in this test, photographs of the back of your eye (fundus) will be taken and can help show what the tumour looks like before and after treatment. The doctor will put eye drops in your eye to widen (dilate) your pupil and then use a special camera to take pictures of the fundus.

Ultrasound scan – this test uses soundwaves to create pictures of the inside of your eye and surrounding areas. For this scan a gel will be spread over your closed eyelid and a small device called a transducer is moved over the area. The transducer sends out soundwaves that echo when they come across something dense, like an organ or tumour. The ultrasound images are then projected onto a computer screen. An ultrasound is painless, takes only a few minutes and accurately shows the size of the tumour.

Transillumination – if you need surgery, this test may be done first to show exactly where the melanoma is. The lights in the room are turned down and the doctor shines a very bright light into your eye to look for abnormal areas.

CT (computerised tomography) or MRI (magnetic resonance imaging) scans – special machines are used to scan and create pictures of the inside  of your body and are used to find tumours or to check for any spread of disease. Before the scan you may have an injection of dye (called contrast) into one of your veins, which makes the pictures clearer. During the scan, you will need to lie still on an examination table. For a CT scan the table moves in and out of the scanner which is large and round like a doughnut; the scan itself takes about 10 minutes. For an MRI scan the table slides into a large metal tube that is open at both ends; the scan takes a little longer, about 30–90 minutes to perform and the machine is noisy so you will be given earplugs to wear. Both scans are painless.

Biopsy – most of the time, the ophthalmologist can make a diagnosis from what they can see when they examine your eye, from photographs and  ultrasound pictures. However, sometimes a biopsy is performed. In a biopsy, some tissue is removed from the affected area so it can be examined  more closely under a microscope.