title: Effects of daily and overnight wear of a novel hyper oxygen-transmissible soft contact lens on bacterial binding and corneal epithelium: a 13-month clinical trial.
abstract: OBJECTIVE
  To test prospectively a new biologic rationale for an advanced hyper oxygen-transmissible lens (HOTL) providing prospects for safer daily (DW) or extended (EW) contact lens wear.
  
  
  METHODS
  Prospective, randomized, double-masked, single-center, 13-month clinical trial.
  
  
  METHODS
  One hundred sixty-eight patients completed the DW study (1 month): control lens (n = 70); HOTL (n = 98). One hundred thirty-six patients finished 1 year of EW: controls (n = 56), HOTL (n = 25, 6 nights; n = 55, 30 nights).
  
  
  METHODS
  Irrigation chamber to collect corneal surface cells, confocal microscopy, tear collection at baseline, 2, and 4, weeks of DW, and 24 hours, 1, 3, 6, 9, and 12 months of EW.
  
  
  METHODS
  (1) Pseudomonas aeruginosa (PA) binding to exfoliated corneal surface cells; (2) central epithelial thickness (CET); (3) superficial cell area (SCA); (4) epithelial surface cell exfoliation (DESQ); and (5) tear lactate dehydrogenase (LDH).
  
  
  RESULTS
  Daily wear with control lens increased PA binding from 5.90 +/- 2.60 to 7.81 +/- 3.04 bacteria per cell (P < 0.01); HOTL wear increased PA binding significantly less (5.31 +/- 1.87-5.98 +/- 2.26; P < 0.01). Daily wear produced no significant changes in CET or SCA. Significant decreases in DESQ were seen with both lenses with no significant intergroup differences. Tear LDH increased significantly in DW with HOTL wear versus control (P = 0.0017), but not after 1 month of subsequent EW (P = 0.533). One to 3 months of EW with control lens showed significantly higher PA binding than HOTL wear (P < 0.01); binding adaptively decreased thereafter, returning to baseline at 9 to 12 months. Lens EW produced significantly enlarged SCA, thinning of CET (except 6-night HOTL wear), and decreased DESQ (P < 0.01). Some adaptive recovery was seen with CET and DESQ, but not SCA; importantly, the data indicated no significant difference between 6- or 30-night EW for all outcomes.
  
  
  CONCLUSIONS
  Hyper oxygen-transmissible lens wear (DW or EW) produced significantly decreased PA binding compared with control lens wear, with no significant difference in wearing schedule (6 nights vs. 30 nights); additionally, there was a remarkable and unexpected adaptive recovery in the first 6 months of all soft lens wear, with a return to baseline PA binding levels and partial recovery for the other outcomes except SCA at 1 year. These results suggest that HOTL use should result in a decrease in the incidence of and risk(s) for lens-related microbial keratitis and that further epidemiologic studies should consider time in adapted EW in future risk and incidence analyses.
authors.affiliation: Department of Ophthalmology, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390, USA. Dwight.Cavanagh@UTSouthwestern.edu
authors.forename: H Dwight
authors.initials: HD
authors.lastname: Cavanagh
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Ladage
authors.forename: Susanna L
authors.initials: SL
authors.lastname: Li
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Mike
authors.initials: M
authors.lastname: Molai
authors.forename: David H
authors.initials: DH
authors.lastname: Ren
authors.forename: W Matthew
authors.initials: WM
authors.lastname: Petroll
authors.forename: James V
authors.initials: JV
authors.lastname: Jester
mesh_terms: D001422:Bacterial Adhesion; D003262:Contact Lenses, Extended-Wear; D004311:Double-Blind Method; D019573:Epithelium, Corneal / Q000382:microbiology*; D005260:Female; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008297:Male; D010100:Oxygen / Q000378:metabolism*; D011446:Prospective Studies; D011550:Pseudomonas aeruginosa / Q000502:physiology*; D013666:Tears / Q000201:enzymology
chemical_list: D007770:L-Lactate Dehydrogenase; D010100:Oxygen