Prevalence and characteristics of choroidal nevi: the Australian National Eye Health Survey.

IMPORTANCE: Choroidal nevi are a common incidental finding on fundus examination. The National Eye Health Survey (NEHS, 2015-2016) provides an up-to-date estimate of the prevalence of choroidal nevi in non-Indigenous and Indigenous Australian adults.

BACKGROUND: To describe the prevalence and characteristics of choroidal nevi among non-Indigenous and Indigenous Australian adults.

DESIGN: Population-based cross-sectional study.

PARTICIPANTS: This study included 3098 non-Indigenous Australians (aged 50-98 years) and 1738 Indigenous Australians (aged 40-92 years) living in 30 randomly selected sites, stratified by remoteness.

METHODS: Choroidal nevi were graded from retinal photographs using standard protocols.

MAIN OUTCOME MEASURES: Prevalence of choroidal nevi.

RESULTS: In the non-Indigenous population aged 50 years and over, the weighted prevalence of choroidal nevi was 2.1% (95% CI: 1.4, 3.3). Among Indigenous Australians aged 40 years and over, the weighted prevalence of choroidal nevi was 0.68% (95% CI: 0.4, 1.3). The average maximum diameter, surface area and distance from the disc of the choroidal nevi was 1730 μm, 2 766 800 μm2 and 3400 μm, respectively. After multivariate adjustments, Indigenous participants (OR = 0.28, P = 0.01) and those of older age (OR = 0.79 per 10 years, P = 0.02) were less likely to have choroidal nevi. Choroidal nevus was not the primary cause of vision loss in any participant.

CONCLUSIONS AND RELEVANCE: Choroidal nevi were relatively infrequent among NEHS participants, however non-Indigenous Australians had a significantly higher prevalence than Indigenous Australians. Choroidal nevi did not affect visual acuity and the majority were small.