Visual Acuity and Mortality in a Chinese Population: The Tanjong Pagar Study
Received 10 October 2006; received in revised form 30 April 2007; accepted 30 April 2007. published online 31 August 2007.
Objective
To examine the relationship between visual acuity and mortality in a Chinese population.
Design
Population-based cohort study.
Participants
Chinese persons in Singapore ages 40 to 79 years at baseline examination.
Methods
The Tanjong Pagar Study in Singapore examined 1232 persons (response rate, 71.8%) at the baseline examination in 1997 and 1998. Participants had measurements of presenting and best-corrected visual acuity (VA) using standardized protocols. Mortality data were obtained from the National Death Registry, which linked subjects who had died since the baseline examination. Cause of death was determined from the International Classification of Diseases 9 codes. Analysis was performed on 1225 (99.4%) participants with VA data.
Main Outcome Measure
All-cause mortality.
Results
By December 31, 2004 (median follow-up, 6.8 years), 126 persons had died. Participants with presenting VA in the better eye worse than 20/40 (logarithm of the minimum angle of resolution [logMAR] score, 0.3) had a significantly higher mortality rate (hazard ratio [HR], 2.9; 95% confidence interval [CI], 1.4–6.3, adjusting for age, gender, hypertension, diabetes, smoking, heart attack, stroke, and income) as compared with participants with VA of 20/20 (logMAR, 0.0). Associations were similar for best-corrected VA in the better eye (HR, 2.7; 95% CI, 1.4–5.5). Among clinic participants with logMAR VA measurements, each 1-line difference in presenting VA (logMAR gain, 0.10) was associated with a 4-fold increased risk of mortality (HR, 4.4; 95% CI, 1.9–10.2).
Conclusions
In this Chinese population in Singapore, visual impairment was associated independently with an increased risk of mortality.
2Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
3Epidemiology & Disease Control Division, Ministry of Health, Singapore.
4Centre for Eye Research Australia, University of Melbourne, Melbourne, Australia.
5Department of Community, Occupational, and Family Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
6Institute of Ophthalmology, University College London, London, United Kingdom.
Correspondence to Tien Yin Wong, PhD, FRANZCO, Centre for Eye Research Australia, University of Melbourne, 32 Gisborne Street, Victoria 3002, Australia.
Manuscript no. 2006-1149.
Supported by the National Medical Research Council, Singapore, and British Council for the Prevention of Blindness, London, United Kingdom.
The authors have no proprietary interests related to the article.
ABSTRACT