Posted by Larry Hoover on March 24, 2009, at 13:17:01
In reply to To Larry H. - epidemology info. question, posted by garnet71 on March 24, 2009, at 8:58:56
> I think I spelled that wrong.
Yup. You missed the i after the d.
> Do you know what's up with the myopia rates in the U.S.?
No, but you made me curious.
> I had read that in Taiwan, something like 84% of young adults now have myopia, and rates of high myopia >6 has doubled since the 80s. Singapore and Japan show similar trends, if I remember correctly, Japan's rates were the highest.
Up to 90%! Sheesh!
> So for the U.S., I could not find any trend data. I'm familiar with the Dept. of HHS stats, not competent, but familiar, and every paper I came across cites practically the same myopia population rates from a study from the 80s. Is there any tracking/trend data for U.S. myopia rates that is current, that you know of?
Not that I know of. The most recent data from NHANES indicates a current prevelance rate at 33%. There is a decline in myopia with age, and they did a study to see if that indicated that age reduced the incidence, or if the younger cohort had a higher rate. It turns out that aging alone best explained the decline in rate with age.
Interesting.
Lar
Arch Ophthalmol. 2008 Aug;126(8):1111-9.
Prevalence of refractive error in the United States, 1999-2004.
Vitale S, Ellwein L, Cotch MF, Ferris FL 3rd, Sperduto R.
Division of Epidemiology and Clinical Research, National EyeInstitute, National Institutes of Health, Bethesda, MD 20892-9301, USA. sev@nei.nih.govOBJECTIVE: To describe the prevalence of refractive error in the United States. METHODS: The 1999-2004 National Health and Nutrition Examination Survey (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, we defined clinically important refractive error 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. RESULTS: 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). CONCLUSION: 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.
Invest Ophthalmol Vis Sci. 2000 Jul;41(8):2103-7.
Age-related decreases in the prevalence of myopia: longitudinal change or cohort effect?
Mutti DO, Zadnik K.
The Ohio State University College of Optometry, Columbus 43210-1240, USA. mutti.2@osu.eduPURPOSE: The prevalence of myopia shows a decline with age in cross-sectional studies. This pattern may represent an increase in the prevalence of myopia in younger generations, possibly through increased exposure to near work, or an intrinsic age-related decline in myopia prevalence. Data were analyzed from published studies to determine which of these two alternatives better explains the data: a cohort effect of changing prevalence by decade or a longitudinal effect of changing prevalence as a function of age. METHODS: Prevalence data were taken from three studies conducted in the late 1980s and compared with those obtained indirectly from a national survey conducted in the early 1970s. The prevalence of myopia was then plotted as a function of age and year of birth. RESULTS: The pattern of change in the prevalence of myopia as a function of age was consistent across all studies when data were scaled relative to the prevalence of myopia at age-range midpoints from 44.5 to 49.5 years. The pattern of change was not consistent as a function of year of birth. When the data were scaled relative to the prevalence of myopia among those with years of birth from 1940 to 1942 and plotted by year of birth, results from the early 1970s were offset from those of later studies by approximately 18 years. CONCLUSIONS: The decline in the prevalence of myopia in older adults between the early 1970s and the late 1980s can be better explained by age than by year of birth. The prevalence of myopia appears to decrease because of an intrinsic age-related decrease in the amount of an individual's myopia rather than because of a cohort effect of increasing prevalence over time. The hypothesis that increasing environmental exposures to near work in recent decades have changed the prevalence of myopia is not supported by this analysis.
poster:Larry Hoover
thread:886785
URL: http://www.dr-bob.org/babble/20090322/msgs/886823.html