title: Contact lens deposits, adverse responses, and clinical ocular surface parameters.
abstract: OBJECTIVE
  To correlate clinical responses during contact lens wear with the amount of protein or cholesterol extracted from lenses after wear.
  
  
  METHODS
  Clinical parameters, including adverse response rates and corneal staining, and symptomatology rating during lens wear were collected from a series of clinical tests comprising four different silicone hydrogel lenses with four different multipurpose solutions. To test for correlates, the amount of total protein or cholesterol extracted from lenses after daily wear were compared statistically to clinical parameters.
  
  
  RESULTS
  The amount of protein (p = 0.008) or cholesterol (p = 0.01) extracted from lenses was higher for those subjects who showed solution-induced corneal staining. Amount of protein extracted was correlated (p < 0.01) with conjunctival staining (R = -0.23), lens front surface wetting (r = 0.14), and lens fit tightness (R = -0.20). These clinical parameters accounted for 48% of lens protein deposition. The amount of cholesterol extracted from lenses was much more weakly associated with clinical variables. Amount of protein or cholesterol extracted from lenses was not associated with the production of any corneal infiltrative or mechanical adverse event during wear and was only very weakly correlated with insertion comfort of lenses.
  
  
  CONCLUSIONS
  These results suggest that there may be no physiologically relevant consequence of cholesterol depositing on silicone hydrogel lenses. The amount of protein that deposits onto silicone hydrogel lenses during wear may have more affect on lens performance on-eye. However, the correlations were generally small and may still not indicate any causative relevant physiological response. Further work is required to determine whether there is any direct causative effect to support these correlative findings.
authors.affiliation: Institute for Eye Research, Sydney, New South Wales, Australia.
authors.forename: Zhenjun
authors.initials: Z
authors.lastname: Zhao
authors.forename: Thomas
authors.initials: T
authors.lastname: Naduvilath
authors.forename: Judith L
authors.initials: JL
authors.lastname: Flanagan
authors.forename: Nicole A
authors.initials: NA
authors.lastname: Carnt
authors.forename: Xiaojia
authors.initials: X
authors.lastname: Wei
authors.forename: Jennie
authors.initials: J
authors.lastname: Diec
authors.forename: Vicki
authors.initials: V
authors.lastname: Evans
authors.forename: Mark D P
authors.initials: MD
authors.lastname: Willcox
mesh_terms: D002784:Cholesterol / Q000032:analysis*; D003228:Conjunctiva / Q000737:chemistry; D003263:Contact Lenses, Hydrophilic / Q000009:adverse effects*; D003315:Cornea / Q000737:chemistry; D005136:Eye Proteins / Q000032:analysis*; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D012828:Silicones; D013194:Staining and Labeling
chemical_list: D005136:Eye Proteins; D012828:Silicones; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D002784:Cholesterol