HEALTH NEWS

Study Title:

Nearsightedness on the Rise

Study Abstract

Objective To compare US population prevalence estimates for myopia in 1971-1972 and 1999-2004.

Methods The 1971-1972 National Health and Nutrition Examination Survey 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 20/40) or retinoscopy (for presenting visual acuity 20/50). Using a similar method for diagnosing myopia, we examined data from the 1999-2004 National Health and Nutrition Examination Survey to determine whether myopia prevalence had changed during the 30 years between the 2 surveys.

Results 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]: 17.5% vs 13.4%, respectively [P < .001]; –2.0 to >–7.9 D: 22.4% vs 11.4%, respectively [P < .001]; –7.9 D: 1.6% vs 0.2%, respectively [P < .001]).

Conclusions 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. Identifying modifiable risk factors for myopia could lead to the development of cost-effective interventional strategies.

From press release:

Myopia (nearsightedness) may have been more common in Americans from 1999 to 2004 than it was 30 years ago, according to a report in the December issue of Archives of Ophthalmology, one of the JAMA/Archives journals.

"Myopia, or nearsightedness, is a common condition in which the image of an object seen in the distance is focused anterior to the retina and is consequently out of focus when it reaches the retina," according to background information in the article. "Blurred vision caused by myopia can be treated by corrective lenses (eyeglasses or contact lenses) or refractive surgery."

Susan Vitale, Ph.D., M.H.S., and colleagues at the National Eye Institute, National Institutes of Health, Bethesda, Md., compared U.S. population prevalence estimates for myopia from the National Health and Nutrition Examination Survey (NHANES) in 4,436 black and white participants from 1971 to 1972 and in 8,339 black and white participants from 1999 to 2004. Participants' ages ranged from 12 to 54. The same methods were used to determine myopia during 1971 to 1972 and 1999 to 2004.

"The prevalence of myopia for individuals aged 12 to 54 years was statistically significantly higher in 1999 to 2004 than in 1971 to 1972 (41.6 percent vs. 25 percent, respectively)," the authors write. "Prevalence estimates were higher in 1999 to 2004 than in 1971 to 1972 for black individuals (33.5 percent vs. 13 percent, respectively) and white individuals (43 percent vs. 26.3 percent, respectively) and for all levels of myopia severity."

Although myopia can be treated with corrective lenses, its high prevalence costs Americans billions of dollars every year. "The question of whether myopia prevalence is increasing is therefore important to health planners and policy makers," the authors conclude. "Identifying modifiable risk factors for the development of myopia could lead to the development of cost-effective interventional strategies."

Study Information

1.Susan Vitale; Robert D. Sperduto; Frederick L. Ferris, III.
Increased Prevalence of Myopia in the United States Between 1971-1972 and 1999-2004.
Arch Ophthalmol,
2009 December
National Institutes of Health, Bethesda, Md.