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RESEARCH STUDY

RESEARCH

Prevalence of Refractive Error in the United States, 1999-2004

AUTHOR:

Susan Vitale, PhD, MHS; Leon Ellwein, PhD; Mary Frances Cotch, PhD; Frederick L. Ferris III, MD; Robert Sperduto, MD

SPONSOR/INSTITUTION:

National Center for Health Statistics (NCHS), Centers for Disease Control and Prevention; National Eye Institute, National Institutes of Health

YEAR PUBLISHED:

2004

PUBLICATION:

Arch Ophthalmol

KEY HIGHLIGHTS:

  • The objective of this study is to describe the prevalence of refractive error in the United States.

  • The study used the 1999-2004 National Health and Nutrition Examination Survey (NHANES) data to estimate the population prevalence of refractive error and to describe the refractive characteristics of the US population in greater detail.

  • The 1999-2004 NHANES used an autorefractor to obtain refractive error data on a nationally representative sample of the US noninstitutionalized, civilian population 12 years and older. Using data from the eye with a greater absolute spherical equivalent (SphEq) value, clinically important refractive error was defined as as follows: hyperopia, SphEq value of 3.0 diopters (D) or greater; myopia, SphEq value of −1.0 D or less; and astigmatism, cylinder of 1.0 D or greater in either eye.

  • Of 14 213 participants 20 years or older who completed the NHANES, refractive error data were obtained for 12 010 (84.5%). The age-standardized prevalences of hyperopia, myopia, and astigmatism were 3.6% (95% confidence interval [CI], 3.2%-4.0%), 33.1% (95% CI, 31.5%-34.7%), and 36.2% (95% CI, 34.9%-37.5%), respectively.

  • Myopia was more prevalent in women (39.9%) than in men (32.6%) (P < .001) among 20- to 39-year-old participants. Persons 60 years or older were less likely to have myopia and more likely to have hyperopia and/or astigmatism than younger persons. Myopia was more common in non-Hispanic whites (35.2%) than in non-Hispanic blacks (28.6%) or Mexican Americans (25.1%) (P < .001 for both).

  • Estimates based on the 1999-2004 NHANES vision examination data indicate that clinically important refractive error affects half of the US population 20 years or older.

  • Refractive error is recognized as one of the most important causes of correctable visual impairment, accounting for nearly 80% of the visual impairment in persons 12 years and older in the United States.

  • Providing eye care services to the many persons who use or need refractive correction involves substantial expense: the direct annual cost of refractive correction for distance visual impairment is estimated to be between $3.8 and $7.2 billion for persons 12 years and older (based on an estimated annual direct cost per person of $35-$56) and, in a separate study of persons 40 years and older, $5.5 billion.

  • The study concluded that estimates based on the 1999–2004 NHANES vision examination data indicate that clinically important refractive error affects half of the U.S. population aged ≥20 years.