Abstract
Purpose: :
To compare the prevalence of myopia in Singapore male military conscripts over a 14 year period from 1996-1997 to 2009-2010.
Methods: :
All new male military conscripts (n=15,086) aged 16 to 26 years were refracted in 1996-1997 and a repeat survey of 29,170 similar aged male conscripts enlisted using the same methods was conducted in 2009-2010. Military service is compulsory for all young males and exemption is only granted for severe medical conditions. The stand-alone autorefractor, the Huvitz MRK-3100P machine was used.
Results: :
The overall prevalence of myopia [spherical equivalent (SE) worse than -0.5 Diopters (D)] increased slightly from 79.3% (95% confidence intervals (CI) 78.6, 80.0) in 1996 to 81.3% (95% CI 81.2, 82.1) in 2009 (p=0.04). The myopia prevalence was highest in Chinese compared with Malays and Indians. The prevalence increased from 82.2 to 85.9 in Chinese (p<0.001), 65.0 to 70.7 in Malays (p<0.001) and 68.7 to 74.5 in Indians (p=0.03). The overall high myopia (SE worse than -6.0D) prevalence increased from 13.1 to 14.8% (p<0.001). In Chinese, the prevalence of high myopia increased from 14.8% to 18.2% (p<0.001), 5.0 to 6.6% in Malays (p=0.011), but there was no significant change (6.3% to 7.2%; p=0.42) in Indians. The increase in myopia prevalence was highest amongst conscripts with elementary education (62.3% to 78.4%; p<0.001), and there was a decrease in conscripts with university education (85.7% to 84.0%; p=0.004).
Conclusions: :
There is a growing epidemic of myopia in Asia as reflected by the secular increase in the prevalence of myopia in young male adults in Singapore over the past 14 years. There is a rise in myopia prevalence in all 3 ethnic groups, but an increase in myopic prevalence only in conscripts with less formal education. This rise may reflect changing environmental lifestyles such as more time reading and less time spent outdoors especially in the less educated and myopia prevalence in conscripts with university education may have reached the maximum threshold.
Keywords: myopia • refractive error development • emmetropization