Abstract
Purpose: :
To investigate the change in lens thickness over a ten year interval.
Methods: :
Study examinations of the Beaver Dam Eye Study cohort pertinent to this analysis occurred at baseline (1988-2000) and ten years later. During the course of the study visit, a medical history was obtained and an eye examination was performed. Slit lamp color photographs were taken after pupil dilation. Slit lamp images were digitized in grey scale. A custom designed program detected lens landmarks along the axis through the center of the lens. The location of these landmarks, in particular those delineating the anterior and posterior capsule of the lens, serve as the basis of the measurements we report. The 10-year change in lens thickness was calculated as the percentage of change relative to the baseline lens thickness.
Results: :
For women and men who were 43-54 years of age at baseline, the mean 10-year change in lens thickness was 4.2% for each gender; for those 55-64 years of age, the change was 2.4% for women and 3.8% for men; for those 65-74 years of age, the change was 2.3% for women and 3.8% for men; and for those 75 years of age or older, the change was 3.0% for women and 4.0% for men. In multivariable analysis including age (as a continuous variable), gender, smoking status, diabetes status, nuclear, cortical and posterior subcapsular cataract status in the model, only older age (p<.0001) and gender (being female, p=.012) were significantly associated with change in lens thickness.
Conclusions: :
Age is the most important correlate of lens thickness and its effect varies by gender. While the mechanisms responsible for these changes are not well known, this change may be a marker of biological aging.
Keywords: aging • cataract • clinical (human) or epidemiologic studies: prevalence/incidence