Abstract
Purpose: :
Contact lenses remain a significant mode of refractive error correction in the United States; however, little data concerning the prevalence of contact lens use and characteristics of the contact lens population is available. The National Health and Nutrition Examination Survey (NHANES) is conducted by the National Center for Health Statistics in continuous two year cycles. As a component of the survey a subset population is evaluated via mobile examination clinics. During visual acuity testing in the mobile clinics it is documented if subjects are using glasses, contact lenses, or a combination of both. Distance visual acuity is taken for subjects age 10 and older and near visual acuity is checked on subjects 50 and older. The project generates generalizable population estimates of demographic characteristics of contact lens wearers in the United States based on NHANES data.
Methods: :
Data from the 2005-2006 and 2007-2008 NHANES were combined and population estimates were generated on weighted four year prevalence using SAS survey-methods accounting for the complex sampling frame of the NHANES.
Results: :
Based on estimates from NHANES participants in the 2005-2008 period 18.6 million Americans [18.7%(95%CI 16.4,20.9)]over age 10 who used refractive correction for distance vision used contact lenses. Contact lens use was highest among teens aged 10-18 39.0%(95%CI 31.9,46.0) and young adults aged >18-40 [37.1%(95%CI 33.3,40.9)] decreasing dramatically to 5.7%(95%CI 4.1, 7.4)]in adults over age 50. Among those over age 50 wearing contacts, 68.2%(95%CI 57.3,79.0) only wore contacts lenses for near vision testing with the remainder using a contact lens and spectacle combination. Non-Hispanic whites accounted for the majority of contact lens wearers 77%; interestingly, within ethnic group analysis shows that contact lens use was highest among those identified as Mexican American 21.3% (95%CI 16.2,26.5) and others[not White, not Hispanic, not African American] 21.3%(95%CI 14.5,28.1) and lowest among African Americans 14.6%(95%CI 11.3,17.9). Females were more frequent users of contact lenses at all ages, and more than doubled male wearers in the population over age 50.
Conclusions: :
Contact lens use decreases dramatically after age 40. Contact lens use appears be more common among some ethnic groups than non-Hispanic whites.
Keywords: contact lens • clinical (human) or epidemiologic studies: prevalence/incidence • clinical (human) or epidemiologic studies: risk factor assessment