Refractive error and biometry in older Chinese adults: the Liwan Eye Study
Mingguang He 1*,
Wenyong Huang 2,
Yuetao Li 2,
Yingfeng Zheng 2,
Qiuxia Yin 2,
and
Paul J. Foster 3
1 State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, 54 Xianlie Road, Guangzhou, 510060, China
2 State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangzhou, China
3 Institute of Ophthalmology, University College London, London, United Kingdom
* To whom correspondence should be addressed. E-mail: mingguang_he{at}yahoo.com.
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Abstract |
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Purpose: To assess the prevalence of refractive error and describe the
distribution of ocular biometry and its association with refraction in adult
Chinese.
Methods: Random clustering sampling was used to identify adults aged 50
years and over in Liwan District, Guangzhou. Refraction was determined by
subjective refraction that achieved the best-corrected vision based on
monocular measurement. Ocular biometry was measured by A-mode
ultrasound using a handheld applanation probe.
Results: Among 1405 participants in the study, data from 1269 phakic right
eyes were available for analysis. The prevalence of myopia (SE<-0.5 D),
hyperopia (SE>+0.5 D), and astigmatism (cylinder>0.75 D) was 32.3% (95%
CI: 27.8-34.6%), 40.0% (95% CI: 37.3-42.7%), and 48.3% (95% CI:
45.6-51.1%), respectively. The spherical equivalent tended to become
hyperopic at 60 years and shift toward myopia at 75 years. Axial length did not
change with age but was consistently shorter in women. Lens thickness
increased with age and tended to be greater in women.
Conclusions: The prevalence of myopia and biometric distribution in this
urban Chinese cohort are similar to those observed in Singaporean Chinese
but greater than in Mongolians and Europeans. Further studies are needed to
clarify the role of environmental factors in the myopia rates.
Key Words:
prevalence, myopia, refractive error , biometry
