Racial differences in lens opacity incidence and progression: The salisbury eye evaluation (SEE) study

PURPOSE. To evaluate racial differences in nuclear and cortical lens opacity incidence and progression over a 2-year period in an older American population. METHODS. Prospective population-based cohort study of a multiethnic population of 2520 people (26% African-American and 74% Caucasian), 65 to 84 years of age, living in Salisbury, Maryland. Data at baseline included race, education level, past steroid use, smoking status, alcohol status, sunlight exposure, and history of hypertension and diabetes. Lens photographs were taken at baseline and at 2-year follow-up and were graded using the Wilmer grading scheme. Multiple logistic regression models were used to examine the independent associations between race, as well as other risk factors, and incidence and progression of cortical and nuclear opacities. RESULTS. African-Americans had lower rates of nuclear opacity incidence (Odds Ratio [OR]: 0.52; 95% Confidence Interval [CI]: 0.35-0.76) and nuclear opacity progression (OR: 0.60; 95% CI: 0.38-0.92) compared with Caucasians. African-Americans had higher rates of cortical opacity incidence (OR: 1.90; 95% CI: 1.21-2.98) and cortical opacity progression (OR: 1.72; 95% CI: 1.21-2.45) compared with Caucasians. Additionally, nuclear opacity incidence was associated with age, female sex, and current smoking status. Nuclear progression was associated with past smoking and current smoking. Cortical opacity incidence was associated with female sex, Ultraviolet-B exposure, and a history of diabetes. Cortical opacity progression was associated with current smoking status. CONCLUSIONS. Differences by race in the type of cataract incidence and progression, even adjusting for personal and environmental risk factors, deserve further exploration.