Myopia in Singapore: taking a public health approach
Benjamin Seet, Tien Yin Wong, Donald T H Tan, Seang Mei Saw, Vivian Balakrishnan, Lionel K H Lee, Arthur S M Lim
Myopia is a problem of public health concern in Singapore for three reasons. Firstly, the prevalence of myopia (more than −0.5 dioptres (D)) is one of the highest worldwide. Twenty per cent of Singapore children are myopic at 7 years at the start of their primary education,1
with prevalence exceeding 70% upon complet- ing college education.2-4 Other population based studies showed myopia prevalence of 15% in preschool 4 year old children,5 80% in military conscripts,6 and nearly 40% in adult Chinese aged 40 and older.7 This is 1.5-3 times higher than similarly aged white or black populations in the United States,8-10 and elsewhere.11 12
Secondly, a large proportion of Singapor- eans has high myopia (more than −6.0 D), which has been observed across the whole age spectrum.1 6 7 While the prevalence of high myopia is less than 2% in most Western popu- lations,10 11 approximately 10% of Singapore adults have the condition.6 7
Thirdly, available data suggest that both prevalence and severity of myopia have in- creased significantly over the past two decades. Based on serial cross sectional data from the Singapore Armed Forces, myopia prevalence in military conscripts has increased from 26% in the late 1970s, to 43% in the 1980s, 66% in the mid 1990s, and 83% by the late 1990s.6 13 14
This is accompanied by a twofold rise in the proportion with myopia worse than −8 D, from 2% to 4% between 1993 and 1997.4 A similar trend of increasing myopia prevalence has been observed in schoolchildren.1 15
The underlying explanation for high myopia prevalence and severity in Singapore is not well understood. Available data suggest that this phenomenon is not unique to Singapore. A high prevalence of myopia has also been described in other east Asian urban popula- tions in Taiwan, Hong Kong, and Japan.16-20 In Taiwan, a substantial increase in the prevalence of myopia in schoolchildren has similarly been observed over the past few decades,16 17 al- though in Japan, the rates may have tapered somewhat.8 19 20 Furthermore, socio- demographic risk factors for myopia in these populations appear to be similar to those reported in the West, and include higher education, higher income, and occupations associated with near work activities.6-8 It is therefore likely that complex and multiple fac- tors, both genetic and environmental, are involved.
In this paper, we systematically examine the impact of myopia in Singapore, propose a model to explain its high prevalence in the population, and outline a strategy for myopia control.
Defining the impact of myopia in Singapore THE MEDICAL PERSPECTIVE
There is concern that blindness from myopia will become a substantial public health prob- lem in the near future. With an ageing popula- tion (more than one third of Singaporeans will be older than 50...