Prevalence of choroidal naevi using scanning laser ophthalmoscope

To determine the prevalence of choroidal naevi in a healthy population using an ultra-wide scanning laser ophthalmoscope which can capture up to a 200° field of view of the retina, without pupil dilation.

Subjects were recruited from a college population. Each subject underwent an eye examination that included retinal and choroidal imaging using the Optos scanning laser ophthalmoscope and completed a self-administered questionnaire. Univariate and multivariate regression analysis were performed to identify associated factors with choroidal naevi.

The Optomap images of 406 participants (mean age 23.5 ± 4.4) were analysed. Thirty-nine subjects (10%) presented with at least one naevus in one eye, and multiple naevi were observed unilaterally in eight subjects. Drusen were noted in only one eye. The mean naevus diameter was 2.38 mm (± 2.07). Prevalence was not associated with either eye colour, time spent outdoors, visual impairment, or ethnic group, but was significantly associated with male gender (OR 2.41, p = 0.009), blond/red hair colour (OR 2.42, p = 0.037), skin that neither burns nor tans (OR 2.8, p = 0.02) and habitual sunglasses use (OR 0.33, p = 0.002).

A higher prevalence of choroidal naevi was detected in this college population compared to other population-based studies. This is likely due to the use of an ultra-wide field scanning laser ophthalmoscope which provides up to 200° of the fundus. The naevi were associated with several factors.