Objective: To estimate the age- and gender-specific prevalence of posterior subcapsular (PSC), nuclear, cortical, and mixed lens opacities in a population-based sample of Latinos 40 years and older.
Design: Population-based, cross-sectional study.
Participants: Six thousand three hundred fifty-seven Latinos 40 years and older from 6 census tracts in Los Angeles, California.
Methods: A population-based sample of Latinos underwent a complete eye examination, including assessment of presence and severity of lens opacification, using the slit lamp-based Lens Opacities Classification System II (LOCS II). All lens changes (including pseudophakia/aphakia); any nuclear, PSC, and cortical opacities; and nuclear-only, PSC-only, and cortical-only opacities were evaluated. Frequency distributions and chi-square test analyses were used to determine the age- and gender-specific prevalences for each opacity type.
Main outcome measures: Prevalences of cortical, nuclear, and posterior subcapsular opacities.
Results: Of the 7789 eligible subjects, 6357 completed a clinical examination (82% participation rate). Of all participants with LOCS II grading, 20% had all lens changes, 7.6% had cortical-only opacities, 3.5% had nuclear-only opacities, 0.4% had PSC-only opacities, and 5.9% had mixed-type opacities. The prevalence of all types of lens opacities increased with age (P<0.0001). Of all participants with mixed opacities, 49% had monocular visual impairment and 20% had binocular impairment. Of all 6357 participants, 3.9% had undergone cataract extraction in at least one eye.
Conclusion: Our data provide the first population-based estimates of the prevalence and severity of lens opacities in Latinos. Cortical opacities were the most common type. The high rate of visual impairment from lens opacities suggests that programs that increase access to cataract surgery for older Latinos could help to reduce the burden of visual impairment in the United States.