title: Frequency and seasonal variation of ophthalmology-related internet searches.
abstract: OBJECTIVE
  To use internet search activity to reveal the intensity of public interest and seasonal variation in ophthalmology-related diseases, symptoms, and treatments.
  
  
  METHODS
  Time-series analysis of internet search data.
  
  
  METHODS
  Google trend data for ophthalmology terms for the United States, the United Kingdom, Canada, and Australia from 2004 through 2008 were studied. Mean population-weighted temperature and fraction of schools in session were estimated from databases, and relative potential sunlight intensity was calculated. Multivariable linear regression was used to predict search term frequency based on environmental variables.
  
  
  RESULTS
  Relative to diabetes searches (100%), common US eye-related searches were: "glasses" (44%), "Lasik" (16%), "contact lenses" (12.4%), "pink eye" (9.5%), "glaucoma" (5.9%), "cataract" (4.1%), "dry eyes" (2.1%), "eye twitching" (1.9%), and "eye pain" (1.9%). Seasonal nature was high for "conjunctivitis" (r(2) = 0.37), "pink eye" (r(2) = 0.32), "eye floaters" (r2 = 0.26), and "stye" (r(2) = 0.19), moderate for "glaucoma" (r(2) = 0.09) and "eye twitching" (r(2) = 0.06), and low for "uveitis" (r(2) = 0.02) and "macular degeneration" (r(2) < 0.01). Heat was associated with "stye" and cold was associated with "pink eye," "conjunctivitis," and "glaucoma" (all p < 0.002). Sunlight intensity was associated with "dry eyes" and "eye floaters" (p < 0.01). School sessions were associated positively with "eye twitching" (p >= 0.001) and negatively with "eyeglasses." "Eye allergy," "itchy eyes," and "watery eyes" were highly seasonal (r(2) = 0.75-0.38) and associated with "pollen" searches.
  
  
  CONCLUSIONS
  Internet ophthalmology searches relate (in decreasing order) to refractive correction, eye diseases, and eye symptoms. Search study reveals the seasonality and environmental associations of interest in health terms.
authors.affiliation: Department of Ophthalmology, Virginia Commonwealth University, MCV Campus, Richmond, VA 23298, USA. cleffler@pol.net
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Leffler
authors.forename: Byrd
authors.initials: B
authors.lastname: Davenport
authors.forename: Dana
authors.initials: D
authors.lastname: Chan
mesh_terms: D054626:Consumer Health Information / Q000706:statistics & numerical data*; D016208:Databases, Factual / Q000706:statistics & numerical data*; D005128:Eye Diseases / Q000453:epidemiology*; D006801:Humans; D020407:Internet / Q000706:statistics & numerical data*; D009885:Ophthalmology / Q000706:statistics & numerical data*; D012621:Seasons