Eye cancer

Tumours of the eye are rare, and their main feature is that they announce themselves late: the eye does not hurt, nothing shows from the outside, and vision can stay good for as long as the tumour has not reached the centre of the retina. That is why many of these tumours are found by chance, at an ordinary sight test, when the examiner dilates the pupil and looks at the back of the eye. Hence the main practical conclusion: a regular eye examination does more than any attempt to keep watch on yourself. In adults the tumour in question is most often melanoma of the uvea, the vascular layer of the eye, and it is covered here in most detail.

Which tumours occur in the eye

The phrase "eye cancer" covers very different diseases, and they are treated in different ways.

• Uveal melanoma is the commonest malignant tumour of the eyeball itself in adults. It grows from the same pigment cells as moles on the skin, but it sits inside the eye, usually in the choroid, the layer of blood vessels beneath the retina.
• Conjunctival melanoma, on the visible surface of the eye: a dark patch on the white of the eye that grows, changes colour or acquires its own blood vessels.
• Squamous cell carcinoma of the conjunctiva: a pinkish or jelly-like thickening at the edge of the cornea, more common in people with many years of sun exposure and where immunity is reduced.
• Eyelid tumours. On the eyelids the commonest is basal cell carcinoma: a slowly growing nodule, or a sore that will not close and where the lashes fall out.
• Lymphoma, a tumour of immune system cells; in the eye and in the tissues of the orbit it shows up as a painless pink thickening or as an eye that gradually pushes forward.
• Retinoblastoma, a childhood tumour of the retina, usually in the very young, and often inherited.
• Secondary deposits from other organs, most often the lung and the breast: a tumour can reach the eye from elsewhere, and sometimes it is the eye that gives the illness away first.

A choroidal naevus deserves a separate word — a mole inside the eye. It is a common finding and in most cases harmless; it is simply watched, with its growth, its thickness and any accompanying changes recorded. Watching here is not a fudge, it is the method.

What the person notices

The symptoms depend on where the tumour has grown, and at first there may be none at all. It is worth being seen if you develop:

• shadows, blobs or cobwebs in the field of vision, flashes of light, wavy lines;
• blurred or distorted vision, with straight lines turned wavy;
• a dark patch on the iris or on the white of the eye that is growing or changing colour;
• loss of part of the visual field, as though a curtain had been drawn across from one edge;
• one eye pushing forward, changing position, or double vision;
• a nodule or lump on the eyelid or on the surface of the eye that keeps growing;
• irritation and redness of one eye that goes on for weeks despite drops;
• pain in or around the eye, which with tumours is rather uncommon.

Almost all of these complaints far more often mean something harmless: a vitreous detachment, a migraine with visual aura, ordinary inflammation. But telling one from the other without looking at the back of the eye is impossible, and that is exactly why the visit should not be put off.

What must not wait

Seek help the same day if you develop:

• sudden loss of vision, or a dark curtain creeping in from the edge of the visual field, particularly together with flashes and a sudden shower of floaters — that is what a retinal detachment looks like, and the window is measured in days;
• severe pain in the eye with redness, coloured haloes around lights, nausea and vomiting;
• an eye pushing forward quickly, especially with double vision and a temperature;
• sudden double vision or a drooping eyelid joined by a severe headache or weakness in the limbs.

A separate word about children. Have a child seen at once if the pupil of one eye gives back a white reflection — in flash photographs one pupil comes out red and the other white or yellowish — if a squint appears that was not there before, or if the eye becomes red and painful for no clear reason. These are the commonest first signs of retinoblastoma, and it responds well to treatment when caught early. In that situation there is no waiting for a routine appointment.

An ambulance is called in whatever way is usual in your country; in Spain, Italy, Portugal, Poland and Ukraine the single European number 112 works.

Who gets it more often

Eye melanoma is more common in people with fair skin and light eyes — blue, grey or green — than in people with brown eyes and darker skin. The likelihood rises with age: most cases occur above the age of fifty. The risk is higher in those with many unusual moles on the skin or a previous skin melanoma, and also where there is congenital grey or bluish pigmentation of the white of the eye and the skin around it.

One common confusion is worth avoiding here. In skin melanoma the link with ultraviolet is firmly established; in melanoma inside the eye it is much weaker and still argued over, and of the external exposures the one that stands out most is years of welding without eye protection. That is no reason to give up sunglasses — they protect the eyelids, the conjunctiva and the lens beyond argument — but nor is it a reason to assume that sunbathing was the cause.

A separate chapter, rare but important, is inherited predisposition. There are families in which eye melanoma runs alongside skin melanoma, kidney tumours and mesothelioma; a change in a single gene lies behind it. If close relatives have had such tumours at a young age, tell your doctor: the family may need genetic counselling and regular eye examinations.

How the eye is examined

The foundation of diagnosis is examination of the back of the eye through a dilated pupil. A tumour inside the eye is seen literally by eye, and often that is enough to suspect it and refer on. After that, a specialist centre will usually arrange:

• an ultrasound scan of the eye — a small probe is placed on the closed eyelid; this measures the thickness of the lesion and its borders, and that figure largely determines the choice of treatment;
• optical coherence tomography, a layer-by-layer image of the retina that shows fluid and the changes above the tumour;
• angiography with a dye — a dye is injected into a vein and the vessels at the back of the eye are photographed in a series;
• assessment of the rest of the body, above all the liver, with blood tests and imaging, because that is where eye melanoma spreads most often.

A biopsy of an intraocular tumour is not always taken, and it is not there to confirm the diagnosis, which is usually made without it. A fine needle collects a few cells so that their genetic features can be examined: these predict fairly reliably how likely the tumour is to spread, and that governs how often the person will be followed up afterwards. Whether to agree to it is worth discussing with the doctor, because the information changes not the treatment of the eye but the follow-up plan.

How it is treated

The choice depends on the size of the tumour, on where it sits, and on whether vision remains. The modern approach tries to keep the eye and, where possible, the sight as well.

• Brachytherapy. A small plate carrying radioactive material is stitched onto the sclera from the outside, directly opposite the tumour, and left for a few days, then removed in a second short operation. This is the commonest way of treating a medium-sized melanoma.
• External beam radiotherapy with a narrow beam, including proton beam, when the tumour sits awkwardly for a plate.
• Laser treatment for small tumours, most often as an addition to radiotherapy.
• Surgical removal of the tumour with the eye preserved, where size and position allow.
• Removal of the eye where the tumour is large or the sight has already gone. A few weeks later a prosthesis matched to the other eye is fitted into the socket; it looks and moves naturally, and other people usually notice nothing.
• Drug treatment where the tumour has spread beyond the eye. Here medicines are used that turn the immune system against the tumour cells. Ordinary chemotherapy is barely used in eye melanoma, but it does have a place in other tumours of the eye, for instance in lymphoma and in retinoblastoma.

After radiotherapy the vision in that eye often declines over time: the retina and the optic nerve suffer, and a cataract may appear. This is explained honestly in advance, because it is part of the price of keeping the eye. The other eye is healthy, and everyday life, work and reading included, carries on.

What happens afterwards

The outlook depends above all on how large the tumour was when it was found, on where it sat, and on the genetic features of its cells. Small tumours picked up at a routine examination behave markedly better than large ones.

What is distinctive about eye melanoma is that it spreads mainly through the blood and almost always to the liver, sometimes many years after the eye itself has been treated successfully. Follow-up here is therefore long: regular visits to the eye specialist and periodic assessment of the liver, on a schedule the doctor will set.

What is worth doing yourself: not missing routine sight tests, especially if you have light eyes, many moles or a previous skin melanoma; wearing sunglasses with a genuine ultraviolet filter and using eye protection when welding; and keeping an eye on pigmented patches on the visible part of the eye, showing them to a doctor if they change. And not putting off an appointment because the eye does not hurt: with tumours of the eye, pain is the exception rather than the rule.

Online consultation

You cannot look inside the eye through a screen, and it is fair to say so at the outset. But a remote appointment solves other problems, and solves them quickly: it helps make sense of the flashes, floaters or shadow that have appeared in the visual field and of how urgently a face-to-face examination is needed, separating complaints that can wait for a routine booking from those that mean going in today. The doctor will look at a photograph of a patch on the white of the eye or on the lid, take a family history, explain what the choroidal naevus found at an examination means, go through a report and treatment plan you have already been given, and help set up the follow-up schedule. The signs in the urgent section, and a white pupil in a child, are not handled at a consultation: with those you are seen in person, the same day.

This material is for information only and does not replace medical advice.