Epidemiologic study of pterygium in Taiwan
- 39 Downloads
To investigate the incidence, prevalence, and factors related to pterygium in Taiwan.
An ecological study
We analyzed a random sample of 1 million individuals in Taiwan drawn from the National Health Insurance Database (NHIRD), established in 2005, for the period 2000 to 2011. Patients with pterygium were identified using ICD-9-CM diagnostic codes. The prevalence and annual age- and gender-adjusted incidence of pterygium were calculated for each county in Taiwan. The risk factors including ultraviolet (UV) exposure, outdoor occupation, educational level, and average socioeconomic status of each county of each index year were identified. Univariate and backward elimination multivariate selection by the mixed-effects model were performed to identify significant risk factors related to the incidence of pterygium in Taiwan.
A total of 22,063 individuals with pterygium (10,125 men and 11,938 women) were identified in this study. The prevalence of pterygium was 2.14% in the overall population and 3.48% in the population aged 40 years or older. The occurrence of pterygium was greater in women. In addition, this study demonstrated that UV exposure and low educational level are correlated with the age- and gender-adjusted incidence of pterygium.
Our study is the first to use the NHIRD to determine the prevalence (2.14%) and annual age- and gender-adjusted incidence of pterygium among the general population of Taiwan. The relationship of pterygium with UV exposure and educational level suggests a complex and multifactorial etiology for this disease.
KeywordsEpidemiology Pterygium Taiwan Ultraviolet exposure
We extend our deepest gratitude to Professor Hsu Kuang-Hung at Chang Gung University, Taiwan, and to Dr Bing-Yu Chen at the Department of Medical Research and Development, Chang Gung Memorial Hospital, Keelung, Taiwan, for their persistent assistance in reviewing our manuscript with the utmost care and for offering us invaluable advice and informative suggestions along the way regarding the statistical analysis. This study was supported by Grants (Nos. CLRPG2C0021-24 and CLRPG2G0081-82 to C.-C. Sun) from the Chang Gung Medical Research Foundation, Taiwan.
Conflicts of interest
Y.-H. Lin, None; C.-C. Sun, None; L. Yeung, None; Y.-W. Yu, None; M.-H. Sun, None; K.-J. Chen, None.
- 6.Liang QF, Xu L, Jin XY, You QS, Yang XH, Cui TT. Epidemiology of pterygium in aged rural population of Beijing, China. Chin Med J (Engl). 2010;123:1699.Google Scholar
- 9.Shiroma H, Higa A, Sawaguchi S, Iwase A, Tomidokoro A, Amano S, et al. Prevalence and risk factors of pterygium in a southwestern island of Japan: the Kumejima Study. Am J Ophthalmol. 2009;148(766–71):e1.Google Scholar
- 21.Lin SF, Tsai RK, Tung IC, Sheu MM. An epidemiologic study of pterygium in middle-aged and elderly aboriginal populations of the Tao Tribe of Orchid Island in Taiwan. Tzu Chi Med J. 2006;18:283–6.Google Scholar