title: Protein deposition and clinical symptoms in daily wear of etafilcon lenses.
abstract: OBJECTIVE
  To determine the relationship between clinical signs and symptoms and protein deposition over 8 h of wear of etafilcon A lenses in symptomatic and asymptomatic contact lens wearers.
  
  
  METHODS
  Thirty adapted soft contact lens wearers (16 symptomatic and 14 asymptomatic) were fitted with etafilcon A lenses. In vivo wettability, non-invasive tear break-up time, and subjective symptoms (vision, comfort, and dryness) were assessed at baseline and after 2, 4, 6, and 8 h. After 2, 4, 6, and 8 h time points, lenses were collected, and total protein, total lysozyme, and active lysozyme deposition were assessed.
  
  
  RESULTS
  There was a significant reduction (p = 0.032) in the non-invasive tear break-up time at 8 h in both groups. In the symptomatic group, there was a significant reduction in subjective comfort and dryness ratings at 6 and 8 h measurement with respect to baseline (p < 0.05). There was a significant increase in total lysozyme and total protein deposition (p = 0.027) across all time points in both groups; most of the lysozyme remained active (>94% at 8 h). Pearson's correlations between subjective symptoms and protein deposition showed poor correlations for total protein/lysozyme and any subjective factor (r < 0.3; p > 0.05), and only weak correlations between dryness and % active lysozyme (r = 0.3 to 0.5 for all time points). However, stronger correlations were found between active lysozyme and subjective comfort (r = 0.6 to 0.7; p < 0.001).
  
  
  CONCLUSIONS
  In addition to investigating total protein deposited on contact lenses, it is of significant clinical relevance to determine the conformational state of the deposited protein.
authors.affiliation: Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada. lnagapat@uwaterloo.ca
authors.forename: Lakshman N
authors.initials: LN
authors.lastname: Subbaraman
authors.forename: Mary-Ann
authors.initials: MA
authors.lastname: Glasier
authors.forename: Jalaiah
authors.initials: J
authors.lastname: Varikooty
authors.forename: Sruthi
authors.initials: S
authors.lastname: Srinivasan
authors.forename: Lyndon
authors.initials: L
authors.lastname: Jones
mesh_terms: D000328:Adult; D003263:Contact Lenses, Hydrophilic; D004586:Electrophoresis; D005136:Eye Proteins / Q000378:metabolism*; D006801:Humans; D015151:Immunoblotting; D008689:Methacrylates; D011474:Prosthesis Design; D011485:Protein Binding; D011795:Surveys and Questionnaires; D013666:Tears / Q000378:metabolism*; D055815:Young Adult
chemical_list: D005136:Eye Proteins; D008689:Methacrylates; C114176:etafilcon; C042434:tear proteins