Four-year incidence and progression of lens opacities preliminary data from the barbados incidence study of eye diseases

PurpOSS- To provide four-year incidence and progression data on lens opacities m a black population, 40 years or older. Methods. The Barbados Incidence Study of Eye Diseases (BISED) followed the cohort from a population-based prevalence study, the Barbados Eye Study (BES), to estimate four-year incidence and progression of major eye diseases, and their risk factors. P-eliminary data included 3155 black participants of the cohort (85% of those eligible). Lens gradings at baseline (BES) and follow-up (BISED) were based on the Lens Op cities Classification System II (LOCS II) at the slit-lamp. A LOCS II score of >2 vas defined as gradable lens opacities, by type. Reproducibility of LOCS II gradingi was maintained throughout BES and BISED. Incidence of nuclear, cortical or posterior subcapsular (PSC) opacities was defined as an increase of two or more steps in the respective LOCS II scores in persons free of opacities in BES. Progression was defined by increases of at least one LOCS II score in persons with pre-existing lens cpacities. Results. The four-year incidences of cortical, nuclear and PSC opacities were 15.6% (95% confidence interval: (14.0. 17.3)), 1.9% (1.4, 2.5), and 2.8% (2 2, 3.5), respectively. Age-specific incidence of these opacity types increased respectively from 17.9%, 0.7%, 1.2% at ages 50-59 years to 38.9%, 10.4%, and 9.2% at ages 70 years or older. Four-year progression rates of cortical (2-step increase), nuclear (1-step increase) and PSC opacities (2-step increase) were 12.4% (10.3, 14.8), 19.1% (1.'.6, 23.0), and 30.6% (16.4, 48.1) respectively. Females tended to have higher incidence of cortical opacities and higher progression of nuclear opacities than males (P=0.0o). Conclusions. Incidence of cortical opacities was high in this Afro-Caribbean population, where opacities of this type are most prevalent. Progression was noted in about one-fifth of persons with nuclear opacities and in one-third of those with PSC opacities.