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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    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 · 3.17 Impact Factor
    • "The prevalence between genders in this study was not significant and also the prevalence for laterality was not significant, whereas regarding location, nasal pterygium was more significant than both temporal and double pterygium [Table 3]. Similar results were found by Lu et al. in China,[23] Viso et al. in Spain,[25] Gazzard et al. in Indonesia,[26] Forsius et al. in Rwanda,[27] Sarac et al. in Turkey.[28] "
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    ABSTRACT: To analyze the epidemiology of pterygium in a hospital-based population in Alkhobar, which is located in the eastern province of Saudi Arabia. This was a retrospective, non-randomized, and consecutive case study. Out of 88,666 patients who were seen in the ophthalmology clinic between January 1995 through the end of December 2010, 116 patients were diagnosed with advanced pterygium. The medical records of these patients were evaluated. The overall prevalence of pterygium was found to be 0.074%. There was no significant difference by either gender, side, or by laterality (P > 0.05). A significant increase was noticed in the prevalence of pterygium with increasing age and nasal location (P < 0.05). The overall prevalence rate of pterygium in Alkhobar is low when compared with results reported from other areas of the world.
    09/2013; 20(3):159-61. DOI:10.4103/2230-8229.121980
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    ABSTRACT: To determine the prevalence and causes of pterygium and pinguecula in the population of Tehran in 2002. In a cross-sectional population study with cluster sampling, 6497 residents of Tehran were selected from 160 clusters. Samples were chosen according to a door-to-door head counting and were then invited for free examinations. After the interview, ophthalmic examinations were performed at an eye clinic. Of the selected sample, 4564 people (70.3%) participated in the study. The age- and gender-standardized prevalence of pterygium in this population was 1.3% (95% confidence interval (CI): 0.9-1.6%). The prevalence of pterygium was 1.4 and 1.1% in men and women, respectively (P>0.05). The prevalence of pinguecula in this study was 22.5% (95% CI: 21.1-24.0%); 27.1% in men and 17.7% in women (P<0.001). In both genders, the prevalence of pterygium and pinguecula showed a significant increase with age (P<0.001). This study concerns the status of pterygium and pinguecula according to age and gender in the population of Tehran. The overall prevalence rates were 1.3 and 22.5% for pterygium and pinguecula, respectively. The comparison of the results with those reported from other areas of the world suggests lower prevalence rates in Tehran.
    Eye (London, England) 07/2008; 23(5):1125-9. DOI:10.1038/eye.2008.200 · 2.08 Impact Factor
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