Eye melanoma

What eye melanoma includes

Ocular melanoma originates in melanocytes within eye tissues. Uveal melanoma affects the iris, ciliary body or choroid and is the most frequent primary intraocular malignancy in adults. This does not make it the most common of all eye lesions, nor does every tumour in the eye represent melanoma.

Conjunctival melanoma, affecting the membrane on the eye’s surface, is biologically and therapeutically distinct. Ocular metastases from a cancer arising elsewhere are another different situation. This section focuses mainly on uveal melanoma.

The disease is rare and occurs mainly in adults and older people. The NCI describes an age-adjusted US incidence of approximately 4.3 uveal melanoma cases per million people per year. This is not an Italian estimate and should not be confused with figures for all eye cancers. Historical figures from 2009 are not current case counts.

Symptoms, risk and prevention limits

A lesion may be found during an examination before it causes symptoms. Possible problems include blurred or distorted vision, flashes, floaters, loss of part of the visual field, a changing iris mark and, less often, pain. These symptoms are nonspecific; sudden loss of vision needs urgent assessment for this and other possible causes.

Light-coloured eyes, certain ocular pigmentation conditions and particular inherited predispositions may contribute to risk assessment. Chromosome 3 abnormalities found in tumour tissue mainly provide biological and prognostic information; they do not automatically mean that the person has an inherited predisposition. Suspected familial syndromes require dedicated counselling.

The relationship between ultraviolet exposure and uveal melanoma is less established than for skin melanoma. Sun protection is sensible for eye health but has not been shown to prevent all uveal melanomas. Skin moles alone cannot predict this tumour.

The ocular diagnostic pathway

Assessment includes examination of the anterior segment and, when appropriate, the dilated fundus. Ophthalmoscopy and ultrasound help identify location, shape and size. Ultrasound biomicroscopy is particularly useful for anterior structures; photographs and other tests document change.

Angiography, optical coherence tomography and MRI may address specific questions. CT and biopsy are not mandatory for every lesion. Uveal melanoma can be diagnosed clinically with imaging; sampling is considered when uncertainty needs resolving or prognostic and molecular information is required, with explanation of its limitations and risks.

Staging and subsequent systemic surveillance take account of uveal melanoma’s tendency to spread to the liver. Investigation schedules depend on risk, and normal blood tests alone cannot exclude spread.

Radiotherapy and eye preservation

Selection depends on location, size, extent, visual function and the person’s circumstances. Brachytherapy uses a plaque carrying a radioactive source temporarily positioned on the outer eye wall beside the tumour. Its duration is planned; removing the plaque does not mean the mass has immediately disappeared.

Proton therapy delivers charged particles to a defined target. Tantalum markers may help localisation but are not themselves the therapeutic radiation source. Proton therapy should not be confused with photon treatment. Selected centres also offer stereotactic techniques.

Preserving the eye does not guarantee preservation of the same vision. Possible consequences include retinopathy, cataract and other complications that should be discussed beforehand. Which technique causes fewer adverse effects depends on location rather than a universal ranking.

Surgery and other local procedures

Enucleation removes the eyeball and may be needed for extensive tumours or a painful, severely damaged eye. Rehabilitation includes orbital assessment and a prosthesis; it is not automatic for every ocular melanoma. Selected iris lesions may be treated with iridectomy or iridocyclectomy, removing part of the iris and, in the latter procedure, part of the ciliary body.

Transscleral local resection and transretinal endoresection are specialist procedures for selected cases. Proximity to the optic nerve alone does not determine their indication, and radiotherapy may be combined with surgery. Transpupillary thermotherapy and other laser procedures have limited or complementary roles; they are not standard solutions for every uncertain lesion.

Intraocular corticosteroid or anti-VEGF injections may treat particular complications, such as swelling or vascular damage after irradiation. Anti-VEGF medicines inhibit angiogenic signals; they are not growth-promoting angiogenic factors and are not equivalent to treatment of the melanoma itself.

Advanced disease and follow-up

Advanced uveal melanoma requires a pathway distinct from skin melanoma. In the European Union, tebentafusp is authorised for HLA-A*02:01-positive adults with unresectable or metastatic uveal melanoma. It is not suitable for everyone; eligibility, availability and toxicity are assessed by the oncologist. Other options and liver-directed treatments may be discussed at expert centres or within trials.

Prognosis depends on size, location, extent and biological features. A single percentage for all ocular melanomas offers little guidance for an individual. Follow-up addresses both the treated eye and its complications and possible systemic spread through a personalised plan.