What should you know about choroidal malignant melanoma?

The choroid is the pigmented, blood-vessel-rich layer behind the retina. A tumour there may be found during a routine eye examination, or after blurred vision, flashes, floaters, a missing area in the field of vision, or a visible change in the eye. These symptoms can have other causes, so they do not establish a diagnosis by themselves.

An ophthalmic oncology team may use a dilated examination, ultrasound and photographs to assess the lesion. They consider its position, size, effect on vision and whether there are signs of spread. The condition differs from skin melanoma, although both involve pigment-producing cells; learn more in the guide to Melanoma.

Keep the specialist appointment and bring a list of medicines, previous eye records and details of when vision changes began. Treatment may aim to control the tumour while preserving useful vision. Options can include focused radiation, removal of the eye in selected circumstances, or another procedure chosen for the tumour's location and extent.

Ask how the proposed treatment may affect sight, eye comfort and daily activities. Follow instructions about eye drops and review visits. Long-term monitoring can include eye checks and assessment of the liver or other organs because this melanoma can spread beyond the eye; follow-up after cancer treatment helps organize that surveillance.

Arrange urgent eye assessment for a sudden loss of vision, a new curtain or shadow, severe eye pain, marked redness, or a sudden burst of flashes and floaters. Seek emergency help when vision loss is abrupt or accompanied by weakness, confusion or a severe headache. A known diagnosis also warrants prompt review of new persistent vision change, yellowing of the skin, abdominal swelling or unexplained worsening fatigue.

Ask where the tumour is located, how its size and features were measured, whether the retina or optic nerve is involved, which treatment preserves the most useful vision, and what warning symptoms should trigger a call. Clarify the visit schedule and which tests will check for spread.