Increased Prevalence of Myopia in the United States Between 1971-1972 and 1999-2004
The goal of this study was to examine whether the prevalence of myopia in the United States had changed during the 30 years between the 1971-1972 and 1999-2004.
The 1971-1972 National Health and Nutrition Examination Survey (NHNES) provided the earliest nationally representative estimates for US myopia prevalence; myopia was diagnosed by an algorithm using either lensometry, pinhole visual acuity, and presenting visual acuity (for presenting visual acuity > or =20/40) or retinoscopy (for presenting visual acuity < or =20/50).
Using a similar method for diagnosing myopia, the sutdy examined data from the 1999-2004 (NHNES) to determine whether myopia prevalence had changed during the 30 years between the 2 surveys.
Using the 1971-1972 method, the estimated prevalence of myopia in persons aged 12 to 54 years was significantly higher in 1999-2004 than in 1971-1972 (41.6% vs 25.0%, respectively; P < .001).
Prevalence estimates were higher in 1999-2004 than in 1971-1972 for black individuals (33.5% vs 13.0%, respectively; P < .001) and white individuals (43.0% vs 26.3%, respectively; P < .001) and for all levels of myopia severity (>-2.0 diopters [D].
The study concluded that when using similar methods for each period, the prevalence of myopia in the United States appears to be substantially higher in 1999-2004 than 30 years earlier.
It also concludes that identifying modifiable risk factors for myopia could lead to the development of cost-effective interventional strategies.