Original article
Prevalence and Risk Factors for Age-Related Macular Degeneration in Indians: A Comparative Study in Singapore and India

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Purpose

To compare the prevalence and risk factors for age-related macular degeneration (AMD) in 2 Indian populations, 1 living in urban Singapore and 1 in rural central India.

Design

Population-based, cross-sectional studies of Indians aged 40+ years.

Methods

Our analysis included 3337 Singapore-residing participants and 3422 India-residing participants. All participants underwent comprehensive systemic and ocular examinations and retinal photography. AMD was graded from retinal photographs according to the Wisconsin Age-Related Maculopathy Grading System. Systemic and ocular risk factors were assessed for association with AMD.

Results

Singapore-residing participants were older (mean age 57.8 years vs 53.8 years) and, after adjusting for age and sex, were more likely to have previous cataract surgery, higher body mass index, hypertension, diabetes, previous myocardial infarction, higher cholesterol, and lower creatinine levels, but less likely to be current smokers, than India-residing participants. The age-standardized prevalence of early and late AMD was 4.45% and 0.34%, respectively, in Singapore and 5.80% and 0.16%, respectively, in India. Shorter axial length was associated with early AMD in both Singapore and India, whereas previous cataract surgery, higher body mass index, hypertension, and lower cholesterol were associated with early AMD in Singapore but not in India.

Conclusion

The prevalence of AMD was similar among Indian adults living in urban Singapore and rural India, despite differences in cardiovascular risk factor profile and demographics.

Section snippets

Study Design and Population

Data from 2 population-based cross-sectional studies of Indian adults in Singapore and India were used. The Singapore Indian Eye Study examined adult Indians aged 40-83 years living in Singapore between August 2007 and December 200916, 17 and was approved by the Singhealth Institutional Review Board. The Central India Eye and Medical Study was conducted in central India in 8 villages comprising the rural region of central Maharashtra at a distance of approximately 40 km from Nagpur from April

Results

Characteristics of the participants are summarized in Table 1. There are marked differences in body weight, height, and BMI; smoking and alcohol intake; medical history (blood pressure, diabetes, cholesterol, history of myocardial infarction); ocular measurements (axial length, central corneal thickness, IOP); and lens status. In particular, the prevalence of diabetes and hypertension were noted to be markedly lower in the India cohort than in the Singapore cohort. We therefore present the

Discussion

In this paper, we estimated and compared the prevalence and risk factors for AMD in 2 Indian populations, an urban Indian population living in Singapore and a rural Indian population living in central India. Singapore is a highly urbanized city-state of 5 million people comprising a multicultural, largely immigrant population of 74.1% Chinese, 13.4% Malays, and 9.2% Indians.25 From a genetic standpoint, the majority of Singapore-residing Indians originate from India; 59.6% of Singapore

Chui Ming Gemmy Cheung is currently a consultant in the Medical Retina Service of the Singapore National Eye Centre, and a clinician investigator of the Singapore Eye Research Institute, Singapore. Her research interests include the study of risk factors and clinical features of macular diseases which may be unique in Asian populations. Dr Gemmy Cheung is the principal investigator of two ongoing prospective clinical studies: the ‘Phenotyping Asian macular diseases study’ and ‘Myopic Macular

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    Chui Ming Gemmy Cheung is currently a consultant in the Medical Retina Service of the Singapore National Eye Centre, and a clinician investigator of the Singapore Eye Research Institute, Singapore. Her research interests include the study of risk factors and clinical features of macular diseases which may be unique in Asian populations. Dr Gemmy Cheung is the principal investigator of two ongoing prospective clinical studies: the ‘Phenotyping Asian macular diseases study’ and ‘Myopic Macular Degeneration study.’

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