Abstract
Aims
To determine the prevalence and identify associated risk factors for pterygium in an elderly Mongolian population at high altitude in Henan County, China.
Methods
A population-based survey was conducted from June 2006 to September 2006. A stratified, clustered, random sampling procedure was used to select 2486 Mongolian people aged 40 years and older. Pterygium was diagnosed and graded clinically as grade 1 (transparent), 2 (intermediate), and 3 (opaque). Risk factors associated with pterygium were evaluated with logistic regression models.
Results
From 2486 eligible subjects, 2112 (84.9%) were examined. There were 378 people with either unilateral (n=228) or bilateral (n=150) pterygia, equivalent to an overall prevalence of 17.9% (95% confidence interval (CI) 16.3, 19.5). The prevalence increased with older age (χ2-test of trend P<0.001). Visual acuity decreased with higher group of pterygium (χ2=97.759, P<0.0001). Pterygium was independently associated with Schirmer's test (⩽5 mm) (odds ratio (OR) 2.4; 95% CI, 1.9, 3.1), tear breakup time (⩽10 s) (OR 2.3; 95% CI, 1.8, 2.9), lower education level (<3 years) (OR 2.1; 95% CI, 1.4, 3.2), increasing age (OR 2.0; 95% CI, 1.4, 2.8) for persons 70–79, compared with 40–49, and other risk factors.
Conclusions
The prevalence of pterygium in an older Mongolian population at high altitude is high, primarily because of ocular sun exposure and the other effects of the unique plateau climate, and representing an important health problem. People should be strongly encouraged to wear a wide-brimmed hat and/or sunglasses whenever they are outside.
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Acknowledgements
We acknowledge local government officials and the workers at the seven township clinics for their painstaking and enthusiastic work. We thank the Henan People's Hospital for its organizational support and the Jian Hua Foundation Ltd for its funding support. We are also grateful to the Mongolian participants for their generous participation in the survey. This work as funded by Jian Hua Foundation Ltd.
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Lu, J., Wang, Z., Lu, P. et al. Pterygium in an aged Mongolian population: a population-based study in China. Eye 23, 421–427 (2009). https://doi.org/10.1038/sj.eye.6703005
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DOI: https://doi.org/10.1038/sj.eye.6703005
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