What Is A Choroidal Naevus?
In between the blood vessels of the choroid, there are cells normally present that contain a black-brown pigment called melanin, which is also present in retinal pigment epithelial (RPE) and skin cells. Occasionally, these cells can increase in number and form a benign choroidal naevus. This is the same as a mole in the skin and is fairly common.
It’s estimated that approximately 4% of white Caucasian adults have a choroidal naevus, and each naevus has just a 1 in 9000 chance of developing into a choroidal melanoma.
Choroidal Naevus Symptoms
A choroidal naevus rarely causes symptoms; it’s usually found during an examination or on retinal photography, and is generally determined through examination.
When examined by a retinal specialist, there are specific features that will be noted and a photograph will be taken for later comparison. An ultrasound scan of the naevus is also often necessary to measure its thickness.
If there are any signs of potential malignancy, it is vital to monitor closely and consider referral to an ophthalmologist with a special interest in eye tumours. Even if there are no signs of malignancy, it has been recommended that a review every six months for two years is a reasonable precaution prior to discharge.
What Does A Choroidal Naevus Look Like?
The dark patch at the bottom of this photograph is a choroidal naevus.
This composite photograph shows a very large malignant melanoma of the choroid that bulges forward and has some orange pigment on its surface (left of the photograph).