title: Comparative Study of Prevalence of Cataract at High Altitude and Kathmandu Valley.
abstract: BACKGROUND
  Cataract is the leading cause of avoidable blindness in the world. Many etiological and risk factors for age related cataract has been documented. The present study is conducted to compare the prevalence of cataract at high altitude and Kathmandu valley.Many etiological and risk factors for age related cataract has been documented.
  
  
  METHODS
  A cross sectional comparative study was conducted at Jomsom, Kagbeni, Jharkot and Muktinath of Mustang district and Balaju and Jawalakhel of Kathmandu valley of Nepal in 2009 to 2011 . There were 222 participants at Mustang and186 participants at Kathmandu. The prevalence of cataract was studied among the Tibetans and Thakali population at Mustang and Tibetans at Jawalakhel and Thakali population at Balaju of Kathmandu valley.
  
  
  RESULTS
  Prevalence of cataract at high altitude was 31.5% and 10.2% at Kathmandu valley. The prevalence of cataract is 4.05 times more at high altitude as compared to Kathmandu valley (p value < 0.001).
  
  
  CONCLUSIONS
  The prevalence of cataract was significantly high at high altitude as compared to lower altitude.
authors.affiliation: Nepal Eye Hospital, Kathmandu, Nepal.
authors.forename: S
authors.initials: S
authors.lastname: Shrestha
authors.affiliation: Patan Academy of Health Sciences, Lalitpur, Nepal.
authors.forename: S M
authors.initials: SM
authors.lastname: Shrestha
authors.affiliation: Dhree Birendra Army Hospital, Kathmandu, Nepal.
authors.forename: A
authors.initials: A
authors.lastname: Gurung
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000531:Altitude; D002386:Cataract / Q000453:epidemiology* / Q000209:etiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009390:Nepal / Q000453:epidemiology; D015995:Prevalence; D012307:Risk Factors; D012737:Sex Factors; D013997:Time Factors; D055815:Young Adult
keywords: Altitude; cataract; prevalence; psedophakia.