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.

Download full-text


Available from: Xiaoliang Chen, Jun 23, 2015
  • Source
    [Show abstract] [Hide abstract]
    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 · 1.90 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To present 9-year incidence data and associated risk factors for pterygium among black participants in the Barbados Eye Studies. Population-based incidence study. A total of 1888 black participants, aged 40 to 84 years, who were free of pterygium at baseline and received an ophthalmologic study examination at the 9-year follow-up. Age and sex-specific 9-year incidence of pterygium is presented. Risk factors were initially identified using Mantel-Haenszel analyses, and significant factors (P<0.10) were subsequently included in multivariate logistic regression models. Odds ratios (OR) and 95% confidence intervals (CI) are provided. Development of pterygium, defined as the presence of a raised fleshy growth that crosses the limbus and encroaches onto the clear cornea. The 9-year incidence of pterygium was 11.6% (95% CI, 10.1-13.1), with no clear pattern with increasing age and no statistically significant differences between genders. Multivariate logistic regression analyses indicated that having a lifetime outdoor job location was positively associated with the development of pterygium (OR = 1.51; 95% CI, 1.05-2.16), whereas darker skin color (OR = 0.67; 95% CI, 0.46-0.97) and use of any prescription lenses (OR = 0.58; 95% CI, 0.42-0.81) were found to be protective factors. The incidence of pterygium was high in this population, for an average of 1.3% per year. Working outdoors increased the risk 1.5-fold, whereas having a darker skin complexion and using eyewear for either reading or distance substantially decreased the risk of developing pterygium. These data suggest that absorption of ultraviolet light plays a role in this condition and that preventive strategies are needed to decrease the burden of pterygium development in this and other populations. The authors have no proprietary or commercial interest in any materials discussed in this article.
    Ophthalmology 10/2008; 115(12):2153-8. DOI:10.1016/j.ophtha.2008.08.003 · 6.17 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To determine the prevalence and risk factors for pterygium in a Japanese population aged 40 years or older on Kumejima Island, Japan. Cross-sectional, population-based study. All residents of Kumejima Island, Japan, located in Southwestern Japan (Eastern longitude 126 degrees, 48 feet and Northern latitude 26 degrees, 20 feet), aged 40 years and older were asked to undergo a comprehensive questionnaire and ocular examination. Of the 4,632 residents, 3,762 (81.2%) underwent the examination. The presence of pterygium could not be determined in 15 subjects. Of the 3,747 eligible subjects, 1,154 (30.8%; 95% confidence interval [CI], 29.3% to 32.3%) had pterygium in at least 1 eye and 491 subjects (13.1%; 95% CI, 12.1% to 14.3%) had pterygium in both eyes. In the logistic regression analysis, older age (P < .001), male gender (P = .024), hyperopic refraction (P = .001), lower intraocular pressure (P = .002), and outdoor job experience (P < .001) were independently associated with a higher risk of pterygium. The prevalence of pterygium is 30.8% among adult Japanese aged 40 years and older in Kumejima. Older age, male gender, hyperopic refraction, lower intraocular pressure, and outdoor job history were independently associated with a higher risk of pterygium.
    American Journal of Ophthalmology 09/2009; 148(5):766-771.e1. DOI:10.1016/j.ajo.2009.06.006 · 4.02 Impact Factor

Similar Publications