Abstract
Purpose: :
To describe the prevalence and 15-year cumulative incidence of lens retrodots (RTD) (also called White Anterior Cortical Opacities, or WACOs) and their associated risk factors in a population-based study.
Methods: :
Of 4,926 persons, 43-86 years of age at the time of a baseline examination in 1988-1990, living in Beaver Dam, Wisconsin, 3,684, 2,764, and 2,119 participated in 5, 10, and 15-year follow-up examinations, respectively. The presence and location of RTD were determined by masked graders using Neitz retroillumination images of the anterior and posterior lens as well as stereoscopic anterior red reflex color photographs. A General Estimating Equation (GEE) approach was used in models to include data from both eyes. Cumulative incidence was estimated after accounting for the competing events of cataract surgery and death.
Results: :
RTD were found in 10% of right eyes at baseline, increasing in prevalence by the 15 year exam to 17%, with the central area of the lens being the most common location (left eyes were similar). As age increased, the prevalence increased (2% 43-54 years, 4% 55-64 years, 14% 65-74 years, and 31% ≥ 75 years). There was no difference in prevalence between men and women after adjusting for age. Both nuclear cataract and visual loss were more frequent when RTD were present compared to when absent. The 15 year cumulative incidence of RTD increases with age (9% 43-54 years, 22% 55-64 years, 29% 65-74 years, and 21% ≥ 75 years). Those persons with nuclear cataract at baseline were more likely to develop RTD over 15 years than in those without nuclear cataract at baseline (Odds Ratio (OR) of 2.5, p<.001) over 15 yrs. In addition, after adjusting for age, gender and nuclear cataract, RTD at baseline are a significant predictor of incident cataract surgery (OR 2.7, p<.001) and a borderline predictor of vision loss (OR 1.3, p=0.1).
Conclusions: :
The presence of RTD increases with age. It is independently associated with both nuclear cataract and vision loss. RTD are an often overlooked change in the lens that may have an impact on vision loss and subsequent cataract surgery.
Keywords: cataract • clinical (human) or epidemiologic studies: prevalence/incidence