Abstract
Purpose: :
Little is known about the epidemiology of contrast sensitivity (CS), an indicator of changes in visual function. The purpose of this paper was to measure the prevalence and predictors of impaired CS in middle-aged adults.
Methods: :
As part of the Beaver Dam Offspring Study (BOSS) of adults 21-84 yrs of age (n=3285; 2005-2008), CS was measured with a standardized protocol using the Pelli-Robson chart. The BOSS examination included extensive questionnaire information about behaviors, environmental factors and medical history. Blood pressure was measured using the Dinamap after a brief rest period. Hypertension was defined as a history of diagnosed hypertension or elevated blood pressure at examination (>140mmHg systolic or >90 mmHg diastolic). Diabetes was defined as a history of diagnosed diabetes or HbA1C>6.1% at examination. Cataract and age-related macular degeneration (AMD) were measured with digital images using standardized grading systems. Impaired CS was defined as a score of <1.55 log units in the better eye. CS data were available for 2835 participants (mean age = 49 yrs).
Results: :
The prevalence of impaired CS was 17.7%. In separate age- and sex-adjusted models, age, sex, smoking, hypertension, diabetes, low education, cataract, AMD, peripheral vascular disease, waist circumference and statin use were associated with impaired CS. In a multivariate model, age (Odds Ratio (OR)=1.23, 95%Confidence Interval (CI) =1.13,1.35; 5yrs), sex (OR=0.42, 95%CI=0.30,0.58; M v F), current smoking (OR=1.95, 95%CI=1.34,2.84), hypertension (OR=1.60, 95%CI=1.15,2.22), statin use (OR=1.55, 95%CI=1.06,2.26), and cataract (OR=2.52, 95%CI=1.58,4.02) were associated with impaired CS. Modeling CS continuously, age, sex, smoking, hypertension, and cataract, as well as diabetes and AMD were associated with poorer CS.
Conclusions: :
These data suggest that impaired CS is frequent among middle-aged adults, increases with age, and may be associated with modifiable exposures. Smoking, hypertension, and diabetes may impact CS through neurological or vascular pathways. Statins may have detrimental effects directly on vision or their use may be a marker for the underlying long-term effects of hyperlipidemia. Longitudinal data are necessary to understand the factors leading to changes in contrast sensitivity with aging.