title: Overnight corneal swelling with silicone hydrogel contact lenses with high oxygen transmissibility.
abstract: OBJECTIVE
  To compare central corneal swelling after 8 hours of sleep in eyes wearing 2 different silicone hydrogel lenses with high oxygen transmissibility.
  
  
  METHODS
  Twenty neophyte subjects were randomly assigned to wear a comfilcon A lens (CooperVision Inc) in one eye and a lotrafilcon A lens (CIBA Vision) in the contralateral eye for an 8-hour overnight period. The study was repeated with another 20 neophyte subjects wearing comfilcon A in one eye only and no lens in the contralateral control eye. Central corneal thickness was measured with optical pachometry before lens insertion, immediately after lens removal on waking, at 20 and 40 minutes, 1 hour, 2 hours and 3 hours.
  
  
  RESULTS
  There was no significant difference between the amount of overnight central corneal swelling induced by the 2 lenses (4.1% +/- 1.9% with comfilcon A vs. 4.0% +/- 1.7% with lotrafilcon A; P>0.05). The swelling of the comfilcon A lens-wearing eyes was significantly higher than that found in the non-lens-wearing contralateral eyes (4.5% +/- 2.1% vs. 3.0% +/- 1.7%; P<0.05).
  
  
  CONCLUSIONS
  The same amount of overnight corneal swelling was induced by the 2 study lenses. The higher overnight swelling observed with the comfilcon A lenses compared to the non-lens-wearing eyes is similar to that reported in the literature for studies using lotrafilcon A lenses.
authors.affiliation: Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada.
authors.forename: Amir M
authors.initials: AM
authors.lastname: Moezzi
authors.forename: Desmond
authors.initials: D
authors.lastname: Fonn
authors.forename: Trefford L
authors.initials: TL
authors.lastname: Simpson
mesh_terms: D000328:Adult; D003262:Contact Lenses, Extended-Wear / Q000009:adverse effects*; D003315:Cornea / Q000000981:diagnostic imaging / Q000378:metabolism*; D015715:Corneal Edema / Q000209:etiology* / Q000378:metabolism; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D020100:Hydrogels; D008297:Male; D010100:Oxygen / Q000378:metabolism*; D012828:Silicones; D014463:Ultrasonography
chemical_list: D020100:Hydrogels; D012828:Silicones; D010100:Oxygen