title: Myopia in young adults is inversely related to an objective marker of ocular sun exposure: the Western Australian Raine cohort study.
abstract: OBJECTIVE
  To determine the association between ocular sun exposure measured by conjunctival ultraviolet (UV) autofluorescence and myopic refractive error in young adults.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  setting: Population-based cohort in Western Australia. study population: Total of 1344 mostly white subjects aged 19-22 years in the Western Australian Pregnancy Cohort (Raine) Eye Health Study. observation procedures: Cycloplegic autorefraction, conjunctival ultraviolet autofluorescence photography, participant questionnaire. main outcome measures: Prevalence of myopic refractive error (spherical equivalent less than -0.50 diopters) and area of conjunctival ultraviolet autofluorescence in mm(2).
  
  
  RESULTS
  There was an inverse relationship between myopic refractive error and ocular sun exposure, with more than double the prevalence of myopia in the lowest quartile of conjunctival autofluorescence than the highest quartile (33.0% vs 15.6%). Median area of autofluorescence was significantly lower in myopic than in nonmyopic subjects (31.9 mm(2) vs 47.9 mm(2), P < .001). These differences remained significant after adjustment for age, sex, parental history of myopia, and subject level of education. The use of corrective lenses did not explain the lower conjunctival autofluorescence observed in myopic subjects.
  
  
  CONCLUSIONS
  In this young adult population, myopic refractive error was inversely associated with objectively measured ocular sun exposure, even after adjustment for potential confounders. This further supports the inverse association between outdoor activity and myopia.
authors: Centre for Ophthalmology and Visual Science, University of Western Australia, Lions Eye Institute, Perth, Australia. Electronic address: mail@charlottemcknight.com.
authors: Charlotte M
authors: CM
authors: McKnight
authors: Centre for Ophthalmology and Visual Science, University of Western Australia, Lions Eye Institute, Perth, Australia; Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, Australia.
authors: Justin C
authors: JC
authors: Sherwin
authors: Centre for Ophthalmology and Visual Science, University of Western Australia, Lions Eye Institute, Perth, Australia.
authors: Seyhan
authors: S
authors: Yazar
authors: Centre for Ophthalmology and Visual Science, University of Western Australia, Lions Eye Institute, Perth, Australia.
authors: Hannah
authors: H
authors: Forward
authors: Centre for Ophthalmology and Visual Science, University of Western Australia, Lions Eye Institute, Perth, Australia.
authors: Alex X
authors: AX
authors: Tan
authors: Centre for Ophthalmology and Visual Science, University of Western Australia, Lions Eye Institute, Perth, Australia; Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, Australia.
authors: Alex W
authors: AW
authors: Hewitt
authors: School of Women's and Infants' Health, University of Western Australia, Perth, Australia; Telethon Kids Institute, Centre for Child Health Research, University of Western Australia, Perth, Australia.
authors: Craig E
authors: CE
authors: Pennell
authors: Centre for Ophthalmology and Visual Science, University of Western Australia, Lions Eye Institute, Perth, Australia.
authors: Ian L
authors: IL
authors: McAllister
authors: Center for Human Genetics, Duke University, Durham, North Carolina.
authors: Terri L
authors: TL
authors: Young
authors: Department of Ophthalmology, University of New South Wales, Sydney, Australia.
authors: Minas T
authors: MT
authors: Coroneo
authors: Centre for Ophthalmology and Visual Science, University of Western Australia, Lions Eye Institute, Perth, Australia.
authors: David A
authors: DA
authors: Mackey
mesh_terms: D003430:Cross-Sectional Studies; D004781:Environmental Exposure / Q000009:adverse effects*; D005123:Eye / Q000528:radiation effects*; D005260:Female; D005544:Forecasting; D006801:Humans; D015994:Incidence; D008297:Male; D009216:Myopia / Q000453:epidemiology* / Q000209:etiology; D011159:Population Surveillance / Q000379:methods*; D011247:Pregnancy; D012029:Refraction, Ocular / Q000528:radiation effects*; D012307:Risk Factors; D013472:Sunlight / Q000009:adverse effects*; D014904:Western Australia / Q000453:epidemiology; D055815:Young Adult