Data are derived from the Eye Diseases Prevalence Research Group (EDPRG),
2–8 the National Health and Nutrition Examination Survey (NHANES) III,
9 the NHANES 1999 to 2008,
10–13 and the National Health Interview Survey (NHIS).
14 Other sources of data include local population-based studies (the Los Angeles Latino Eye Study [LALES],
15–18 Wisconsin Epidemiologic Study of Diabetic Retinopathy [WESDR],
19 and the Beaver Dam Eye Study [BDES]).
20
The EDPRG was a collaborative effort that combined data from up to 10 different studies of mostly European-derived populations, but including cohorts with persons of African or Mexican heritage: the Baltimore Eye Survey, the Barbados Eye Study, the BDES, the Blue Mountains Eye Study, Proyecto Vision Evaluation and Research, the Rotterdam Study, the Salisbury Eye Evaluation Project, the San Antonio Heart Study, the San Luis Valley Diabetes Study, and the Melbourne Visual Impairment Project.
3–8 The number of studies contributing data depended upon each study's availability of information on a given disease or visual function. The purpose of this collaborative effort was to estimate prevalence in the year 2000 of visual impairment and of five specific eye conditions (refractive error, cataract, open-angle glaucoma, DR, and AMD) in people 40 years of age or older and to project prevalence estimates to the year 2020.
2 The data in these studies were collected from as early as 1980 to as recently as 2000. An attempt was made to standardize diagnostic criteria among the studies. The EDPRG's findings were presented in an issue of the
Archives of Ophthalmology in 2004 and included tables and figures showing the prevalence of the specific condition by age, sex, and race/ethnicity for each study and combined estimates of prevalence and total numbers of persons of each condition in the United States (US) by age, sex, and race/ethnicity. These papers, along with their tables and figures, are available electronically.
3–8
The NHANES was conducted by the National Center for Health Statistics at the Centers for Disease Control and Prevention.
9,11,12,22,23 A stratified four-stage area probability sampling procedure was used to obtain a cross-sectional representative sample of the US civilian noninstitutionalized population aged 13 years and older for the NHANES III. It provided estimates of the prevalence of AMD and DR based on gradings of fundus photographs between 1988 and 1994 (one 45° nonstereoscopic field centered on the optic nerve head). In the 2005 to 2008 survey, two 45° nonstereoscopic fields, one centered on the optic nerve head and the other on the fovea of both eyes, were taken of people 40 years of age and older. In the 1999 to 2004 and 2005 to 2008 NHANES, the best-corrected visual acuity was measured and prevalence estimates of visual impairment were reported.
11,13,24,25
The NHIS Vision Health supplement published in 2002 provides data based on self-reported diagnosed eye conditions (
Table 1).
14 The survey, involving 31,044 persons aged 18 years and older, was conducted by the US Census Bureau through in-person household interviews. The household response rate for the NHIS was 89.5%.
In the current paper, we include data from the LALES because of the limited amount of data on Hispanics, especially for cataract status.
15 The study involved examination of 6357 Latinos 40 years and older living in six census tracts in Los Angeles, California. It included standard protocols to measure visual acuity and the grading of lens for identification of presence and severity of cataract at the slit lamp using the Lens Opacity Classification System II and fundus and optic disc photography; the Wisconsin Age-Related Maculopathy Grading System and the Airlie House classification scheme for DR were used in the grading of these photographs. The main outcomes included the prevalence and incidence of visual impairment, blindness, cataract, glaucoma, DR, and AMD. More detailed information is presented elsewhere.
15