Choroidal naevi or moles at the back of the eye: frequently asked questions

Naevi, also commonly known as moles or freckles, are more or less pigmented lesions that can appear in different parts of the body, especially on the skin and also, although less frequently, at the back of the eye (in a tissue called the posterior uvea or choroid). Although in most cases choroidal naevi do not represent a serious health problem, it is important to know that they require highly specialised medical attention.

What are choroidal naevi?

Choroidal naevi are pigmented lesions located in the posterior uvea or choroid, a layer of the eye situated beneath the retina.

How are they different from skin moles?

• They are not related to sun exposure.
• They are usually congenital or develop in childhood.
• Unlike skin moles, they are not visible to the naked eye and require an ophthalmic examination to detect them.

Should I be worried if I have a naevus in the eye?

Although the vast majority of these naevi are benign, some can grow over time. In exceptional cases, there is a risk of transformation into melanoma.

How is an ocular naevus monitored?

Regular monitoring of a naevus is essential. The ophthalmologist must carry out a thorough examination to rule out clinical signs that could entail a higher potential risk of conversion to a malignant lesion.

Specialised ophthalmic examination

Monitoring should include:

• Retinal photography with autofluorescence
• Ocular ultrasound
• Optical coherence tomography (OCT)

Risk factors that are assessed

The ophthalmologist evaluates:

• The size, extent and height of the naevus
• Documented growth across successive visits
• The presence of fluid or pigment
• The lesion’s ultrasound response

Based on these findings, the frequency of follow-up will be determined.

What is the likelihood of a naevus turning into melanoma?

According to the international literature, only 0.0005% of choroidal naevi progress to melanoma. However, if several signs of progression appear, it is advisable to carry out:

• Assessment by a multidisciplinary medical team
• Staging investigations to rule out metastases

Treatment in cases of ocular melanoma

Cases compatible with melanoma, even small ones, should be treated with very specialised conservative methods:

• Laser
• Local radiotherapy (brachytherapy)
• Conservative surgery
• Enucleation of the eye, if the lesion is very extensive or resistant to other treatments

Choroidal naevi are usually benign lesions, but they require specialised ophthalmic surveillance. At the Barraquer Ophthalmology Centre, we have the technology and experience needed for the diagnosis and follow-up of these lesions, guaranteeing safe and personalised management.

Frequently asked questions about naevi in the eye

1. Is it dangerous to have a naevus at the back of the eye?
   Not always, but it does require follow-up to detect any change.

2. Can a naevus at the back of the eye cause pain?
   The naevus does not cause pain.

3. How often should it be checked?
   Depending on the associated clinical signs, every 6 to 24 months.

4. Can naevi turn into melanoma?
   Yes, although it is uncommon, and the risk factors for transformation are known: changes in size, pigmentation or the presence of fluid.

5. What tests do I need?
   Examination of the back of the eye (fundus examination), photography, OCT and, sometimes, ultrasound.

6. Can a benign naevus be operated on?
   It is not usually necessary, unless it causes symptoms.

7. Do naevi appear because of the sun or genetics?
   They are not clearly linked to the sun, but there may be a genetic predisposition.

Dr. Javier Elizalde, ophthalmologist at the Barraquer Ophthalmology Centre