The prevalence and determinants of pterygium in rural areas

PURPOSE To evaluate the prevalence of pterygium and its determinants in the underserved, rural population of Iran. METHODS In this cross-sectional study of 3851 selected individuals, 86.5% participated in the study, and the prevalence of pterygium was evaluated in 3312 participants. A number of villages were selected from the north and south of Iran using multistage cluster sampling. Pterygium was diagnosed by the ophthalmologist using slit-lamp examination. RESULTS The mean age of the study participants was 37.3 ± 21.4 years (2-93 years), and 56.3% (n = 1865) of them were women. The prevalence of pterygium was 13.11% [95%confidence interval (CI):11.75-14.47]. The prevalence of pterygium was 14.99 (95%CI:12.79-17.19) in men and 12.07 (95%CI:10.3-13.84) in women. Pterygium was not seen in children below the age of 5 years. The prevalence of pterygium increased linearly with age; the lowest and highest prevalence of pterygium was observed in the age group 5-20 years (0.19%) and 61-70 years (28.57%). Evaluation of the relationship between pterygium with age, sex, educational level, and place of living using a multiple model showed that age, living in the south of Iran, and low educational level were correlated with pterygium. CONCLUSION The prevalence of pterygium was significantly higher in Iranian villages when compared with the results of previous studies. This finding may represent the effect of a rural lifestyle and its risk factors.