title: Corneal thickness after overnight wear of an intraocular pressure fluctuation contact lens sensor.
abstract: OBJECTIVE
  To assess the effect of overnight wear of a contact lens-based sensor (CLS) for monitoring of 24-hr intraocular pressure (IOP) fluctuations on central corneal thickness (CCT).
  
  
  METHODS
  Changes in the CCT, mid-peripheral corneal thickness and central corneal radius (CCR) during overnight CLS wear in 20 eligible patients with ocular hypertension or established glaucoma were prospectively studied using ultrasound pachymetry and topography. Corneal thickness and CCR changes were evaluated from pre-to-postsleep, with the fellow eye as control. Paired t-test or Wilcoxon signed-rank test was used as appropriate and with α = 0.05. Relationship between the IOP profile recorded by the CLS and the pre-to-postsleep corneal thickness differences was assessed using the Spearman correlation coefficient.
  
  
  RESULTS
  After CLS wear, mean CCT had changed from 523 to 537 μm (p = 0.015) in the study eye and from 518 to 522 (p = 0.206) in the fellow eye (n = 15). There was no difference in CCT change between eyes (p = 0.075). There were no statistically significant changes in horizontal or vertical CCR in either eye (p > 0.05 for all). No correlation was found between the pre-to-postsleep differences in the CLS signal and the pre-to-postsleep differences in ultrasound CCT measurements (p = 0.974).
  
  
  CONCLUSIONS
  The continuous IOP monitoring does not appear to be affected by differences in corneal thickness that occur during overnight CLS wear, although the CLS did induce some corneal swelling. This effect was not statistically significantly different from the control eye and does not seem to influence the CLS IOP profile.
authors.affiliation: Department of Ophthalmology, Julius Maximilians University, Wuerzburg, Germany. f.freiberg@augenklinik.uni-wuerzburg.de
authors.forename: Florentina J
authors.initials: FJ
authors.lastname: Freiberg
authors.forename: Jeanette
authors.initials: J
authors.lastname: Lindell
authors.forename: Luisa A-L
authors.initials: LA
authors.lastname: Thederan
authors.forename: Swetlana
authors.initials: S
authors.lastname: Leippi
authors.forename: Yanan
authors.initials: Y
authors.lastname: Shen
authors.forename: Thomas
authors.initials: T
authors.lastname: Klink
mesh_terms: D002940:Circadian Rhythm / Q000502:physiology*; D003261:Contact Lenses / Q000706:statistics & numerical data*; D003315:Cornea / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D063171:Corneal Pachymetry; D019781:Corneal Topography; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D011446:Prospective Studies; D014065:Tonometry, Ocular / Q000295:instrumentation*; D014160:Transducers, Pressure; D014463:Ultrasonography; D014792:Visual Acuity / Q000502:physiology