title: Crossover Evaluation of Silicone Hydrogel Daily Disposable Contact Lenses.
abstract: OBJECTIVE
  To assess the surface tear breakup time and clinical performance of three daily disposable silicone hydrogel contact lenses over 16 hours of wear.
  
  
  METHODS
  Thirty-nine patients (mean [± SD] age, 22.1 [± 3.5] years) bilaterally wore (narafilcon A, filcon II-3, and delefilcon A) contact lenses in a prospective, randomized, masked, 1-week crossover clinical trial. Tear film was assessed by the tear meniscus height (TMH), ocular/contact lens surface temperature dynamics, and lens surface noninvasive breakup time at 8, 12, and 16 hours of wear. Clinical performance and ocular physiology were assessed by subjective questionnaire, by high-/low-contrast logMAR (logarithm of the minimum angle of resolution) acuity, and through bulbar and limbal hyperemia grading. Corneal and conjunctival staining were assessed after lens removal.
  
  
  RESULTS
  Delefilcon A demonstrated a longer noninvasive breakup time (13.4 [± 4.4] seconds) than filcon II-3 (11.6 [± 3.7] seconds; p < 0.001) and narafilcon A (12.3 [± 3.7] seconds; p < 0.001). A greater TMH (0.35 [± 0.11] mm) was shown by delefilcon A than filcon II-3 (0.32 [± 0.10] seconds; p = 0.016). Delefilcon A showed less corneal staining after 16 hours of lens wear (0.7 [± 0.6] Efron grade) than filcon II-3 (1.1 [± 0.7]; p < 0.001) and narafilcon A (0.9 [± 0.7]; p = 0.031). Time was not a significant factor for prelens tear film stability (F = 0.594, p = 0.555) or TMH (F = 0.632, p = 0.534). Lens brand did not affect temperature (F = 1.220, p = 0.308), but it decreased toward the end of the day (F = 19.497, p < 0.001). Comfort, quality of vision, visual acuity and contrast acuity, and limbal grading were similar between the lens brands but decreased with time during the day (p < 0.05).
  
  
  CONCLUSIONS
  The tear breakup time over the contact lens surface differed between lens types and may have a role in protecting the ocular surface.
authors.affiliation: *BSc, PhD, FAAO †BSc, PhD ‡BEng, PhD Ophthalmic Research Group, Aston University, Aston Triangle, Birmingham, United Kingdom (JSW, OAH, PB, TD, AS); and School of Health Professions, Faculty of Health and Human Sciences, University of Plymouth, Plymouth, United Kingdom (SM).
authors.forename: James S
authors.initials: JS
authors.lastname: Wolffsohn
authors.forename: Stephanie
authors.initials: S
authors.lastname: Mroczkowska
authors.forename: Olivia A
authors.initials: OA
authors.lastname: Hunt
authors.forename: Paramdeep
authors.initials: P
authors.lastname: Bilkhu
authors.forename: Tom
authors.initials: T
authors.lastname: Drew
authors.forename: Amy
authors.initials: A
authors.lastname: Sheppard
mesh_terms: D000328:Adult; D001831:Body Temperature / Q000502:physiology; D003263:Contact Lenses, Hydrophilic; D015350:Contrast Sensitivity / Q000502:physiology; D018592:Cross-Over Studies; D004209:Disposable Equipment; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D008297:Male; D017060:Patient Satisfaction; D011446:Prospective Studies; D012828:Silicones; D011795:Surveys and Questionnaires; D013666:Tears / Q000737:chemistry; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: D012828:Silicones; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate