We report the initial cross-sectional results of a long-term
cohort study in Singapore. This report consists of the entry data on
children aged 7 to 9 years studied in 1999. The study was approved by
the Ethics Committee, Singapore Eye Research Institute and followed the
tenets of the Declaration of Helsinki. Permission to conduct the study
was obtained from the Ministry of Education of Singapore. The study was
supported by the principals and teachers of the two schools. To sample
children from schools with different overall academic performance, two
elementary schools were selected based on prior National Examination
results of their students. One school in the Eastern part of Singapore
ranked among the top 20 schools in the country, and the other school in
the Northern part of Singapore ranked among the bottom 20 schools. All
children in grades 1 and 2, aged 7 to 8 years, in the Eastern school
(n = 639), and grades 1 to 3, aged 7 to 9 years, in the
Northern school (n = 988) were invited to join the
study. Written informed consent was obtained from the parents after the
nature of the study was explained. Children who had a serious medical
condition, such as leukemia or heart disorders, or a
syndrome-associated with myopia or any serious eye disorder, such as
congenital cataract, were excluded. Similarly, children allergic to eye
drops or who refused the instillation of cycloplegic eye drops were
excluded. Three hundred and nine children (48.4%) from the Eastern
school and 696 children (70.4%) from the Northern school elected to
participate. The proportion of children who reported nearsightedness
before the school eye examination was not different in those who
elected to participate (27.3%) and those who did not (26.8%). In
total, there were 522 children aged 7 years, 321 children aged 8 years,
and 162 children aged 9 years. In our sample, there were 729 Chinese
(72.5%) and 276 non-Chinese children (19.4% Malays, 5.6% Indians,
and 2.5% children of other races).