Cataract and mortality in an Afro-Caribbean population: the Barbados eye studies

ABSTRACT

OBJECTIVE: Age related cataract is the major cause of visual impairment globally, and is more prevalent in black than white populations. Several studies have shown associations between cataract and mortality, and this report aimed to examine whether lens opacities were associated with mortality in an Afro-Caribbean population. DESIGN AND METHODS: The Barbados Incidence Study of Eye Disease (BISED) re-examined the Barbados Eye Study (BES) cohort, which was based on a simple random sample of Barbadian-born citizens, age 40 to 84 years. Eighty-five percent of those eligible (3,427 participants) has a 4-year follow-up visit. Both visits included an interview, anthropometric measurements, and a detailed ophthalmologic examination, including lens grading with the LOCS II method. Mortality was verified from records held at the Ministry of Health. RESULTS: Cardiovascular disease was the principal cause of death (3.7 percent), followed by malignant neoplasms (1.4 percent). Cumulative 4-year mortality increased from 3.1 percent among those without cataract to 6.0 percent, 8.9 percent and 19.6 percent for cortical-only, nuclear-only and mixed cataract, respectively. An independent association was demonstrated between mixed opacities and 4-year mortality (death rate ratio 1.6). Co-existing diabetes acted as an effect modifier, increasing mortality in those with mixed lens opacities. The presence of any nuclear cataract (death rate ratio 1.5) was also associated with an increase risk of death. CONCLUSION: This study is the first to confirm an association between cataract and mortality in a population of African descent.(AU)