Choroidal nevi in children: prevalence, age of onset, and progression

To determine the age of onset and prevalence of choroidal nevi in children.

In this cross-sectional study, the fundus photographs of a pooled sample of children 6 months to 18 years of age with 6-year longitudinal follow-up who participated in the Sydney Paediatric Eye Disease Study, Sydney Myopia Study, and the Sydney Adolescent Vascular Eye Disease Study were reviewed. Prevalence by age, clinical features, and longitudinal follow-up assessment was undertaken.

Of 5,533 children (7,059 examinations), 48 children with a choroidal nevus were identified. Prevalence increased with age: <6 years, 0.47%; 6 years, 0.63%; 12 years, 1.06%; 18 years, 1.79%. Nevus was unilateral in all cases (100%), and the majority were melanotic (46, 96%). Most (36 [75%]) were irregular in shape, with ill-defined margins (45 [94%]). All identified nevi were posterior to the equator. All nevi were small, with the average largest basal diameter of 1.6 mm (range, 0.5-3.2) and were not associated with secondary changes (drusen, orange pigment, subretinal fluid). The majority (18/31 [58%]) of nevi remained stable, with 5 of 31 (16%) demonstrating subtle growth (minimum of 600 μm). Four new-onset nevi were documented. Malignant transformation was not observed in any of the nevi.

In our study cohort, the prevalence of choroidal nevi increased with age up to 18 years. The distribution and prevalence of choroidal melanocytic lesions reported herein can be used for designing population-based studies in children that incorporate emerging imaging technologies.