Methodology of the Singapore Indian Chinese Cohort (SICC) eye study: quantifying ethnic variations in the epidemiology of eye diseases in Asians.
OBJECTIVE
Current knowledge of ethnic variability in the epidemiology of major eye diseases in Asia is limited. This report summarizes the rationale and study design of the Singapore Indian Chinese Cohort (SICC) Eye Study, a population-based study of ethnic South Asian (Indians) and East Asian (Chinese) older adults in Singapore.


METHODS
The SICC examined a population-based cross-sectional sample of 3,300 ethnic Indians and 3,300 ethnic Chinese aged 40-80+ years residing in the South-Western part of Singapore.


RESULTS
From two lists of 12,000 names of each ethnic group provided by the Ministry of Home Affairs, age-stratified random sampling was used to select 6,350 names in each group, with a target sample size of 3,300. Invitations were sent to attend a central clinic using letters, telephone calls and home visits. Examination procedures included interviews, measurement of blood pressure, anthropometry, presenting and best-corrected visual acuity, subjective refraction, ocular biometry, Goldmann applanation tonometry, slit-lamp biomicroscopy, optic disc imaging and digital photography of the lens and retina, using a standardized protocol. Selected participants underwent gonioscopic examination, visual field testing, and anterior and posterior segment optical coherence tomography. Blood, tear, and urine samples were collected for biochemical analyses, and stored for genetic and proteomic studies.


CONCLUSIONS
In conjunction with the Singapore Malay Eye Study, the SICC study will permit an in-depth evaluation of the prevalence, risk factors, and impact of major eye diseases in Chinese, Indians and Malays, three distinct Asian ethnic groups, whose combined numbers represent half the world's population.
Lavanya
Raghavan
R
Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.
Jeganathan
V Swetha E
VS
Zheng
Yingfeng
Y
Raju
Prema
P
Cheung
Ning
N
Tai
E Shyong
ES
Wang
Jie Jin
JJ
Lamoureux
Ecosse
E
Mitchell
Paul
P
Young
Terri L
TL
Cajucom-Uy
Howard
H
Foster
Paul J
PJ
Aung
Tin
T
Saw
Seang Mei
SM
Wong
Tien Y
TY
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000208:ethnology*; D002681:China / Q000208:ethnology; D003430:Cross-Sectional Studies; D004812:Epidemiologic Methods; D005006:Ethnicity; D005128:Eye Diseases / Q000208:ethnology*; D005260:Female; D006801:Humans; D007194:India / Q000208:ethnology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012029:Refraction, Ocular; D012307:Risk Factors; D012846:Singapore / Q000453:epidemiology; D011795:Surveys and Questionnaires; D014792:Visual Acuity; D019987:Persons with Visual Disabilities / Q000706:statistics & numerical data*