title: Soft Contact Lens-Related Symptoms in North America and the United Kingdom.
abstract: To characterize and compare the prevalence of soft contact lens-related (SCL) dryness symptoms in large populations of SCL wearers in North America (NAm) and the United Kingdom (UK).
  
  
  
  SCL wearers from NAm (n = 1443) and UK (n = 932) sites completed self-administered questionnaires on SCL symptoms and wearing experiences. A categorization for contact lens-related dry eye (CL-DE) was applied that combined Contact Lens Dry Eye Questionnaire (CLDEQ) items on dryness frequency and intensity at the end of the day (CL-DE+ = constantly/frequently/sometimes plus intensity = 3-5, and CL-DE- = never/rarely plus intensity = 0-1, Marginal = all other ratings). Data were analyzed across regions and categories, with p-values <0.05 significant.
  
  
  
  Compared to UK wearers, those in NAm wore fewer toric and multifocal designs, and reported significantly longer average and comfortable wearing times (p < 0.001) but similar levels of general and end-of-day comfort. The prevalence of CL-DE+ differed between the UK and NAm: CL-DE+: 31 vs. 39%, Marginal CL-DE: 13 vs. 14%, and CL-DE-: 56 vs. 47%, p = 0.0001. Although daily disposable (DD) lenses were worn more commonly in the UK than NAm (33 vs. 10%, p < 0.0001), their use did not impact the overall prevalence of dryness symptoms. Between regions, NAm wearers reported significantly more frequent and intense end-of-day discomfort and dryness (p < 0.0001) and were significantly more likely to use treatments for CL-related symptoms yet experienced a lower degree of relief.
  
  
  
  SCL wearers in NAm reported longer hours of wear with significantly more symptoms of dryness and discomfort. NAm wearers used dryness treatments more often, but experienced less relief than UK wearers. In both regions, the CL-DE categorization was useful to predict poorer comfort, shorter comfortable wearing time, and increased use of treatments. These results highlight the need to benchmark SCL performance locally or regionally to understand and focus on the challenges to the lens wearing experience.
authors.affiliation: *OD, FAAO †MPhil, PhD, FCOptom, FAAO ‡PhD §MSc Clinical Trial Consultant, Atlanta, Georgia (RLC); Visioncare Research Ltd, Farnham, United Kingdom (GY, CH); and Alcon Research, Ft. Worth, Texas (JK, LN).
authors.forename: Robin L
authors.initials: RL
authors.lastname: Chalmers
authors.forename: Graeme
authors.initials: G
authors.lastname: Young
authors.forename: Jami
authors.initials: J
authors.lastname: Kern
authors.forename: Leslie
authors.initials: L
authors.lastname: Napier
authors.forename: Chris
authors.initials: C
authors.lastname: Hunt
mesh_terms: D000328:Adult; D003263:Contact Lenses, Hydrophilic / Q000009:adverse effects* / Q000706:statistics & numerical data; D004209:Disposable Equipment; D015352:Dry Eye Syndromes / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D009656:North America / Q000453:epidemiology; D000070659:Patient Comfort; D015995:Prevalence; D012307:Risk Factors; D011795:Surveys and Questionnaires; D006113:United Kingdom / Q000453:epidemiology