What is a choroidal naevus?
You can think of this as being like a mole at the back of the eye. They are usually spotted incidentally by an optician or at an eye check in hospital for other reasons. They very rarely cause any problems.

Can choroidal naevi become malignant?
Malignant transformation of a naevus (to become a choroidal melanoma) has certainly been described, but the vast majority of choroidal naevi will never do this. There are many documented risk factors that can help stratify risk for choroidal melanoma. Your eye surgeon will be able to assess your naevus and advise you whether you are at higher risk or not.

What tests do I need for my choroidal naevus?
If a colour photograph can be captured, that helps enormously both in documenting the baseline appearance, and also if detailed comparisons are needed in future, to help determine if the naevus has started to grow. If an OCT scan can be captured through the naevus, that can help to exclude the presence of subretinal fluid overlying the naevus, which is one of the documented risk factors that raises suspicion of a melanoma. B-mode ultrasound is sometimes used to measure the thickness of the lesion, to help with diagnosis or sometimes when monitoring response of a choroidal melanoma to treatment with plaque radiotherapy.