To evaluate the risk factors of pterygium in dry, high altitude provine of Ilam, Iran.

The study group consists of patients presenting to ophthalmology clinic of Imam Khomeini hospital, Ilam. Study subjects were divided into two groups: 210 cases diagnosed with pterygium or pinguecula (unilateral or bilateral), and 210 normal controls. Demographic variables, living environment, Disease type, laterality of disorder, familial history and history of smoking, outdoor working, baking or welding, diseases(Keratitis trachomatis, glaucoma, hyperopia and myopia), glass use, dry eye, ultraviolet exposure, and systemic conditions were collected from both groups and compared regarding risk assessment.

Family history, cigarette smoking, history of bakery and blepharitis were significantly associated with an increased incidence of pterygium ,( p= .000, .000,.002 and .002, respectively). Factors such as age, sex, type of profession, primary residence location, level of education, UV confronting, hyperlipidemia, thyroid disease, diabetes, ischemic heart disease and obesity had no significant association with an increased incidence of pterygium.

This study mentioned more risk factors related to prevalence of pterygium rather than the previous studies and confirmed the previous studies’ results. Family history and blepharitis were of risk factors that have not been reported in previous studies and showed significant association with development of ptrygium.