Prevalence of Lens Opacities in Adult Chinese Americans: The Chinese American Eye Study (CHES)

PURPOSE. We determined the age- and sex-specific prevalence of posterior subcapsular (PSC), nuclear, cortical, and mixed lens opacities in a population-based sample of Chinese-American adults. METHODS. A population-based sample of Chinese-Americans 50 years and older, from 10 census tracts in Monterey Park, CA, USA, underwent a detailed interview and a comprehensive clinical examination that included assessment of different types of lens opacities by the slit-lamp-based Lens Opacities Classification System II (LOCS II). All lens changes (including pseudophakia/aphakia), PSC, nuclear, and/or cortical opacities, were evaluated and graded. RESULTS. Of the 5782 eligible subjects, 4582 (79.2%) Chinese Americans aged 50 years and older completed a comprehensive eye examination. Of the participants with LOCS II grading (n = 4234/4582, 92%), 3.0% had PSC opacities, 38.1% had nuclear opacities, and 23.4% had cortical opacities. The prevalence of all lens changes was 48.0% for all age groups and was higher by 10-year increasing age groups (P < 0.0001). The prevalence of visual impairment in the better-seeing eye with cortical only, nuclear only, PSC only, and mixed opacities was 3.9%, 5.0%, 14.3%, and 9.4%, respectively. A total of 454 (9.9%) individuals had undergone cataract extraction in at least one eye. CONCLUSIONS. Chinese Americans have a high prevalence of visual impairment associated with lens opacities, and a high prevalence of nuclear opacities. Public health policies and programs designed to improve cataract detection and treatment could help reduce the burden of visual impairment in Chinese Americans.