title: Prevalence of Pterygia in Hawaii: Examining Cumulative Surfing Hours as a Risk Factor.
abstract: To examine the association between surfing and pterygium prevalence in Hawaii.
  
  
  
  A convenience sampling was performed at four beaches on the island of Oahu, Hawaii. A total of 169 individuals were interviewed and underwent penlight examination to assess grade and extent of pterygium.
  
  
  
  Of 169 participants aged 18-80 years, 88 non-surfers, 41 occasional surfers, 15 recreational surfers and 25 surfing enthusiasts were identified based on their lifetime surfing hours. Overall, 19 participants were found to have pterygia (28 pterygia total) including two non-surfers (2.3%), five occasional surfers (12.2%), three recreational surfers (20.0%), and nine enthusiast surfers (36.0%). Variables associated with pterygium prevalence were lifetime surfing hours (p < 0.0001), outdoor occupation (p = 0.04), Hawaiian residence (p = 0.009), and Hawaiian/Pacific Islander ethnicity (p = 0.002). Multiple logistic regression with the outcome of pterygium was performed, along with multiple linear regression for the continuous outcomes of corneal extent, chord length, and apex-visual axis gap, with lifetime surfing hours as the primary explanatory variable. After adjustment for confounders, a significant linear relationship was observed between chord length and lifetime surfing hours (p = 0.01).
  
  
  
  Surfing was associated with an increased pterygium prevalence and trend towards an association with increased pterygium severity. Increased risk of exposure to wind, particle irritation, and ultraviolet (UV) radiation while surfing may contribute to pterygium development. Implications for public health include promoting UV protective eyewear during surfing, in addition to raising awareness about the association of pterygia and the sport of surfing.
authors.affiliation: a John A. Burns School of Medicine , Honolulu , HI , USA.
authors.forename: Alexander D
authors.initials: AD
authors.lastname: Lin
authors.affiliation: a John A. Burns School of Medicine , Honolulu , HI , USA.
authors.forename: Ku'ulei
authors.initials: K
authors.lastname: Miles
authors.affiliation: b Ophthalmology Department , Oregon Health Sciences University , Portland , OR , USA.
authors.forename: Mitchel V
authors.initials: MV
authors.lastname: Brinks
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006254:Hawaii / Q000453:epidemiology; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011625:Pterygium / Q000453:epidemiology* / Q000209:etiology; D012307:Risk Factors; D013550:Swimming / Q000706:statistics & numerical data*; D055815:Young Adult
keywords: Hawaiian Pacific Islander; prevalence; pterygium; surfing; ultraviolet light exposure