What Factors are Associated with Myopia in Young Adults? A Survey Study in Taiwan Military Conscripts

Abstract

PURPOSE. We investigated the independent impact of potential risk factors on myopia in young adults. METHODS.A survey study was conducted with male military conscripts aged 18 to 24 years between February 2010 and March 2011 in Taiwan. The participants were examined using non-cycloplegic autorefraction and biometry. The participants provided data about potential risk factors, including age, parental myopia, education, near work, outdoor activity, and urbanization. Myopia was defined as the mean spherical equivalent of the right eye of 0.5 diopters (D).RESULTS. Among 5145 eligible participants, 5048 (98.11%) had refraction and questionnaire data available; 2316 (45.88%) of these received axial length examination. The prevalence of myopia was 86.1% with a mean refractive error of À3.66 D (SD ¼ 2.73) and an axial length of 25.40 mm (SD ¼ 1.38). Older age, having myopic parents, higher education level, more time spent reading, nearer reading distance, less outdoor activity, and higher urbanization level were associated with myopia and longer axial length. More computer use was related to longer axial length. All risk factors associated with myopia also were predictors of high myopia ( À6.0 D), with the exception of outdoor activity. Finally, an interaction analysis showed shorter axial length was associated with more time spent outdoors only at high urbanization level. CONCLUSIONS.Older age, parental myopia, higher education level, more near work, less outdoor activity, and higher urbanization level were independent predictors of myopia. These data provided evidence to the multifactorial nature of myopia in young men in Taiwan. (Invest Ophthalmol Vis Sci.

Differences in Prevalence of Refractive Errors in Young Asian Males in Singapore between 1996–1997 and 2009–2010

“…Table 4 gives a summary of studies examining the prevalence of myopia in young Asian and White men. [14][15][16][17][18] In particular, there were two studies on Korean male conscripts who were living in urban and rural environment. 15,16 The higher prevalence of myopia and high myopia in the urban population suggested that living environment may play a significant role in the development of myopia.…”

Light levels, refractive development, and myopia – A speculative review

“…Mutti et al (2002) initially reported that myopia prevalence was inversely related to time spent participating in sports. Several subsequent studies also have shown that outdoor activity is inversely related to the development of myopia (Dirani et al, 2009; Guo et al, 2013; Jones et al, 2007; Jones-Jordan et al, 2011; Lee et al, 2013; Onal et al, 2007; Rose et al, 2008a; Sherwin et al, 2012b; Wu et al, 2010). Some studies have reported that it is the time outdoors, independent of physical activity, that is the important variable (Guggenheim et al, 2012; Rose et al, 2008a).…”

Serum 25-hydroxyvitamin D level is associated with myopia in the Korea national health and nutrition examination survey

“…[7–9] Although the cause of myopia is as yet unclear, genetic and environmental factors may contribute to its development. [10–15] Some recent studies suggested that increasing time spent outdoors may prevent the development of myopia, [14–17] although the results of some epidemiological studies oppose this theory. [18,19] …”