Myopia - 2012 Lancet review

From the Lancet:

Myopia (nearsightedness) has emerged as a major health issue in east Asia, because of:

- increasingly high prevalence in the past few decades. It now affacts 80-90% in school-leavers.
- sight-threatening pathologies associated with high myopia, which now affect 10-20% of those completing secondary schooling in east Asia.

Similar, but less marked, changes are occurring in other parts of the world.

The higher prevalence of myopia in east Asian cities seems to be associated with increasing educational pressures, combined with life-style changes, which have reduced the time children spend outside.

There are no reported major genes for school myopia, although there are several genes associated with high myopia. Any genetic contribution to ethnic differences may be small.

There are some optical and pharmacological interventions that seem promising for preventing the development of myopia or slowing its progression, but the evidence is still preliminary.

References:

Myopia. Prof Ian G Morgan PhD a b , Prof Kyoko Ohno-Matsui MD c, Prof Seang-Mei Saw PhD. The Lancet, Volume 379, Issue 9827, Pages 1739 - 1748, 5 May 2012.
Nearsighted kids may get worse in winter http://trib.in/VcvmC1 -- Myopia progression seem to decrease in periods with longer days and to increase in periods with shorter days. Children should be encouraged to spend more time outside during daytime to prevent myopia (study) http://buff.ly/X1cFSm
Image source: OpenClipArt.org

Myopia, the most common refractive error, has a prevalence of 10-30% in Western countries, but as high as 80% in Asia

Myopia (nearsightedness), the most common form of refractive error, has a prevalence of about 10-30% in most Western countries, but this figure is as high as 80% in parts of Asia. Furthermore, myopic refractive error is likely to progress during school years, and maintaining appropriate spectacle correction requires regular services for children in these age groups.

A study of self correction of refractive error among young people in rural China showed that although visual acuity was slightly worse with self refraction than automated or subjective refraction, acuity was excellent in nearly all these young people with inadequately corrected refractive error at baseline. Inaccurate power was less common with self refraction than automated refraction.

Self refraction could decrease the requirement for scarce trained personnel, expensive devices, and cycloplegia in children’s vision programs in rural China.

References:

Self correction of refractive error among young people in rural China: results of cross sectional investigation. BMJ 2011; 343 doi: 10.1136/bmj.d4767 (Published 9 August 2011).

Nearsightedness (myopia) becoming more frequent, affects 42% of Americans

Correcting refractive error in low income countries. BMJ 2011; 343 doi: 10.1136/bmj.d4793 (Published 9 August 2011).

20-20-20 rule: For every 20 minutes of reading a screen take a 20-second eye break, look at something beyond 20 feet. NYTimes, 2012.

Nearsighted kids may get worse in winter http://trib.in/VcvmC1 -- Myopia progression seem to decrease in periods with longer days and to increase in periods with shorter days. Children should be encouraged to spend more time outside during daytime to prevent myopia (study) http://buff.ly/X1cFSm

Image source: OpenClipArt.org.