Pterygium in an aged Mongolian population: A population-based study in China

Institute of Developmental Biology, Lanzhou University, China.
Eye (London, England) (Impact Factor: 2.08). 11/2007; 23(2):421-7. DOI: 10.1038/sj.eye.6703005
Source: PubMed


To determine the prevalence and identify associated risk factors for pterygium in an elderly Mongolian population at high altitude in Henan County, China.
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.
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 (chi (2)-test of trend P<0.001). Visual acuity decreased with higher group of pterygium (chi (2)=97.759, P<0.0001). Pterygium was independently associated with Schirmer's test (< or =5 mm) (odds ratio (OR) 2.4; 95% CI, 1.9, 3.1), tear breakup time (< or =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.
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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Available from: Xiaoliang Chen, Jun 23, 2015
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    • "The Handan Study chose a similar rural population as the present study; however, the difference in age and sex distribution as well as geographic locations between Handan and Shandong may account for the different prevalence. The pterygium prevalence in Shandong was lower than that in Henan County of Mongolian (17.9%) [7] and Zeku County of Tibetans (14.49%) [8] which are at the high altitude in China and in Doumen County (33.01%) [10] which is located in the south of China with a typical subtropical climate. The prevalence of pterygium varied with races and geographic locations worldwide (Table 5) [12–26]. "
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