Background: To determine the risk of growth of presumed choroidal nevi in the adult Chinese population in Greater Beijing.
Methods: The Beijing Eye Study is a population-based study performed in 2001 and in 2006. Out of 126 subjects with presumed choroidal nevi detected in 2001, 75 (60%) subjects returned for the follow-up examination and had readable fundus photographs available. To assess any change in size or shape of the nevi, we used a flicker comparison of the fundus photographs.
Results: An enlargement of the presumed choroidal nevi was detected in 4 (5.3±22.6% (mean±standard deviation); 95% confidence intervals (CI): 0.1%, 10.5%) eyes during the five-year follow-up. In additional 4 (5.3±22.6%; 95% CI: 0.1%, 10.5%) eyes, drusen of the retinal pigment epithelium overlying the nevi increased in size. None of the nevi regressed in size nor showed clinical signs indicating a malignant transformation. The age of the 4 participants with an increase in the nevus size was 43, 45, 46, 56 years respectively at baseline of the study, best corrected visual acuity was 1.0, and frequency doubling perimetry results were normal.
Conclusions: Adult Chinese with an age of 40+ years show an enlargement of presumed choroidal nevi in only a small percentage of subjects during a follow-up of 5 years. Taking into consideration that most of the study participants were already past the age of the highest risk of developing a uveal melanoma in Chinese, the results may suggest a low risk of growth of choroidal nevi into malignant choroidal melanomas in Chinese.