title: Factors associated with pterygium based on history and clinical examination of patients in Pakistan.
abstract: OBJECTIVE
  The purpose of this study was to determine the factors associated with Pterygium, utilizing history and examination.
  
  
  METHODS
  In this prospective case series study, a total of 1227 patients with Pterygium presenting at the Department of Ophthalmology, Chandka Medical College Hospital Larkana, Pakistan, from January 1997 to January 2015 were included. A standard proforma containing proposed risk factors was filled in for every patient. Clinical examination was performed on slit-lamp biomicroscope to confirm presence of pterygium.
  
  
  RESULTS
  Out of the total 1227 patients, 656 (53.46%) were males, and 571 (46.54%) were females. Mean age ± standard deviation was 53.12 years ± 15.85 years, and the age range was 20-79 years. 1063 (86.63%) patients belonged to areas with hot and dry weather, 421 (34.31%) patients had a positive family history for Pterygium, 740 (60.31%) patients had history of previous exposure to toxic chemicals, and 364 (29.67%) patients had dry eye.
  
  
  CONCLUSIONS
  This study points towards the simultaneous role of multiple risk factors including sun exposure, hot climate, toxic material exposure, familial transmission, and dry eye in association with pterygium.
authors.affiliation: Department of Ophthalmology, Chandka Medical College/SMBB Medical University, Larkana, Pakistan.
authors.forename: Syed Imtiaz Ali
authors.initials: SI
authors.lastname: Shah
authors.affiliation: Department of Ophthalmology, Chandka Medical College, Larkana, Pakistan.
authors.forename: Shujaat Ali
authors.initials: SA
authors.lastname: Shah
authors.affiliation: Department of Ophthalmology, Chandka Medical College/SMBB Medical University, Larkana, Pakistan.
authors.forename: Partab
authors.initials: P
authors.lastname: Rai
keywords: Climate; Dry; Family history; Hot; Pterygium