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

Institute of Developmental Biology, Lanzhou University, China.
Eye (London, England) (Impact Factor: 1.9). 11/2007; 23(2):421-7. DOI: 10.1038/sj.eye.6703005
Source: PubMed

ABSTRACT 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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    ABSTRACT: Purpose: To determine the prevalence of and associated risk factors for pterygia development in a high-latitude-dwelling Northern Chinese population. Methods: A prospective population-based survey was conducted between November 2008 and July 2009. A stratified, clustered, randomized sampling procedure was used to select 8445 subjects, aged ≥18 years, all with diagnosed, graded pterygia. Risk factors associated with the occurrence of pterygia were evaluated according to logistic regression models. Results: A total of 8445 residents (aged 18–94 years) from the Heilongjiang Province, China, participated in the study. Of these, 208 (2.5%) had at least one diagnosed pterygium. The prevalence of bilateral pterygia was 1.2% (95% confidence interval, CI, 1.0–1.4%). According to multivariable analysis, pterygia were significantly more likely to occur in persons aged 70–94 years than in those aged 18–39 years (odds ratio, OR, 29.0, 95% CI 13.6–61.6, p < 0.01). Pterygia were significantly associated with male sex (OR 1.9, 95% CI 1.4–2.6, p < 0.01) and outdoor work (OR 1.8, 95% CI 1.2-2.6, p < 0.01). Multivariable analysis indicated that pterygia were not associated with smoking status (OR 1.0, 95% CI 0.8–1.4) or alcohol intake (OR 1.0, 95% CI 0.7–1.4, p > 0.05). Conclusions: This study details the occurrence of and risk factors for pterygia in a Chinese population residing in a rural, high-latitude, cold-climate area of Northern China. The primary risk factors for pterygia were age, male sex, and outdoor work.
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    ABSTRACT: To investigate the prevalence and risk factors for pterygium in rural older adults in Shandong Province, eastern China, a population-based, cross-sectional study was performed from April to July 2008. By means of cluster random sampling methods, a total of 19,583 people aged 50 years or above were randomly selected from four rural counties. Out of 19,583 people, 1,767 residents were excluded mainly because they were migrant workers when this study was performed. Finally, 17,816 (90.98%) people were included as eligible subjects. They received a comprehensive eye examination and a structured questionnaire voluntarily. Patients with pterygium were defined as having pterygium at the time of survey or pterygium surgery had been performed. 1,876 people were diagnosed as pterygium, either unilateral (1,083) or bilateral (793), which is equivalent to a prevalence of 10.53% (95% CI, 10.08-10.98). The multivariate logistic regression analysis showed that pterygium was independently associated with older age, areas, outdoor time, educational level, and use of hat and/or sunglasses. The prevalence of pterygium increased with age and hours spent under sunshine per day. Meanwhile, the higher the educational level and the more use of hat and/or sunglasses, the lower the pterygium prevalence.
    BioMed Research International 06/2014; 2014:658648. DOI:10.1155/2014/658648 · 2.71 Impact Factor


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