Prevalence And Associated Risk Factors Of Pterygium In Older Adults In Rural Shandong Province Of China

OBJECTIVE:Ptergium is a common ophthalmic disease. The prevalence of pterygium in different places were various, and recurrent rate after surgical excision is high, So taking effective measures to prevent the formation of pterygium is significant in solving the ophthalmic problem. The study, according to analysing the data of the epidemiologic survey on ocular diseases among olders adults aged50years and above in rural populations in Shandong Province, China, aimed to evaluate the prevalence and analyse the associated risk factors of pterygium among these populations.METHODS:Population-based randon cluster sampling method was adopted in this epidemiological survey.3countries of the different economic development level and a representative outskirts country were selected, geographically defined cluster sampling was used in randomly selecting a cross-section of residents aged50years and above from each country(1). All eligible participants underwent a professional ophthalmic examination and completed a standard questionnaire about associated risk factors for the development of pterygium.Statistical analysis was performed using SPSS16.0for windows.x2-test was used to compare the the prevalence of each group, the influence of genderr、age、region education background、occupation、 outdoor work history、smoking、drinking、glasses and systemic diseases on the development of pterygium was estimated by the Logistic regression analysis.RESULTS:Of the19583subjects aged50years and above,17816participants (examination rate90.98%) underwent the examinations.There were1876cases of pterygium, the prevalence was10.5%[95%confidence interval (CI),10.1%to11.0%].the rates of pterygium among males was10.4%(809/7803)(95%CI, 9.7%~11.0%), and the rates of pterygium among females was10.7%(1067/10013)(95%CI,10.1%~11.3%), the difference of prevalence rates between gender had no statistical significant.of the1876cases,793cases (42.3%;95%CI,40.0%to44.5%) had monocular ptergium and1083cases (57.7%;95%CI,55.5%to60.0%) had binocular pterygium.The prevalence of binocular cases was higher than that of monocular cases (χ2=89.658, p=0.000).The prevalence rate of outdoor workers was10.6%(1867/17689)(95%CI,10.1%~11.0%), which was1.5times as high as that of indoor workers [7.1%(9/127)(95%CI,2.6%~11.6%)], although the difference had no statistical significant in the χ2-test (p=0.205). The differences of the prevalence rates among education background were statistically significant in the x2-test (P=0.018). The prevalence rate of participants spending more than4hours per day on outdoor activities[11.9%(95%CI,11.1%~12.7%)]was higher than that of participants who spent less or equal to4hours on outdoor activities[(9.7%(95%CI,9.2%~10.3%), p=0.000)]. the rate of pterygium of participants wearing glasses while going out [(1.3%,95%CI,0.4%-2.1%)] was significantly lower than that of participatants who did not wear glasses [(10.9%(95%CI,10.4~11.3%), p=0.000)]. The differences of incidence rate between the history of somking (p=0.418)、drinking (p=0.415)、hypertension (HP)(p=0.854)、cardiac (p=0.277) and Storke (p=0.387) were not statistically significant in the x2-test.Based on best-corrected visual acuity (BCVA), the prevalence of presenting visual impairment was0.7%and presenting blindness caused by pterygium was0.2%.In the logistic regression analysis, pterygium formation was associated with age、region、glassese、hangout time and education background (p<0.05)CONCLUSIONS:Pterygium, with high prevalence rate, is a common public health problem in rural populations aged50years and above in Shandong Province. the older age、more hours spending on outdoor activities and education background were associated with the formation of pterygium.Wearing glasses when farmers in the outdoor work can significantly reduce the incidence of pterygium.