Prevalence of lens opacities in the Barbados Eye Study

ABSTRACT

OBJECTIVE: To present population-based data on type and extent of age-related lens opacities in the predominantly black population of the Barbados Eye Study. DESIGN: Prevalence study. SETTING AND PARTICIPANTS: The Barbados Eye Study included 4709 participants (84 percent of those eligible), who were identified from a random sample of Barbadian-born citizens aged 40 to 84 years. DATA COLLECTION Lens gradings at the slit lamp, obtained with the use of the Lens Opacities Classification System II. MAIN OUTCOME MEASURE: Prevalence of posterior subcapsular, nuclear, and cortical opacities (defined as a grade > or = 2 in either eye), as well as prevalence of any lens changes (including history of previous cataract surgery and/or cataract too advanced to grade). RESULTS: Overall, 41 percent of the Barbados Eye Study population had any lens change, including 3 percent with aphakia or an intraocular lens. Among the population of African descent, cortical opacities (34 percent) were most prevalent, followed by nuclear (19 percent) and posterior subcapsular (4 percent) opacities. Prevalence of all opacity types increased with age (P < .001). Cortical and nuclear opacities were more frequent in women than men. When prevalence of a single kind of opacity was considered, 21 percent of participants had cortical only, 6 percent had nuclear only, and 0.4 percent and posterior subcapsular only; 13 percent had mixed opacities. Visual acuity loss to worse than 20/40 in the more affected eye was present in 48 percent, 26 percent, and 18 percent of nuclear only, posterior subcapsular only, and cortical only types, respectively, and in 53 percent of mixed opacities. CONCLUSIONS: The Barbados Eye Study provides the first prevalence data on different types of lens opacities in a large, predominantly black population. Whereas nuclear opacities are most common in white populations, cortical opacities were the most frequent type in the Barbados Eye Study, a finding of possible etiologic relevance. Other results highlight a higher frequency of opacities in women than men and a high prevalence of visual acuity loss in affected eyes.(AU)