title: Intraocular pressure measurement over soft contact lens by rebound tonometer: a comparative study.
abstract: OBJECTIVE
  To evaluate the intraocular pressure (IOP) measurements by Icare rebound tonometer over a contact lens in comparison with Goldmann applanation tonometry (GAT).
  
  
  METHODS
  Fifty patients using contact lens were included in this study. One of the eyes of the patients was selected randomly and their IOP were measured by rebound tonometer with and without contact lens (RTCL, RT respectively) and by GAT, as well as their central corneal thickness (CCT) by optical pachymeter. The results of both methods were compared by correlation analysis, general linear method repeated measure and Bland-Altman analysis.
  
  
  RESULTS
  Mean IOP values measured by RTCL, RT and GAT were 15.68±3.7, 14.50±3.4 and 14.16±2.8 (P<0.001), respectively. Mean IOP by RTCL was significantly higher than the measurements implemented by RT and GAT (P<0.001), while there was no difference between the measurements by GAT and RT (P=0.629). There was a good level of positive correlation between GAT and RTCL as well as RT (r=0.786 P<0.001, r=0.833 P<0.001, respectively). We have observed that CCT increase did not show any correlation with the differences of the measurements between RTCL and RT (P=0.329), RTCL and GAT (P=0.07) as well as RT and GAT (P=0.189) in linear regression model.
  
  
  CONCLUSIONS
  The average of the measurements over contact lens by rebound tonometer was found to be higher than what was measured by GAT. Although this difference is statistically significant, it may be clinically negligible in the normal population.
authors.affiliation: Department of Ophthalmology, Tepecik Traning and Research Hospital, Izmir 35240, Turkey.
authors.forename: Senay Asik
authors.initials: SA
authors.lastname: Nacaroglu
authors.affiliation: Department of Ophthalmology, Tepecik Traning and Research Hospital, Izmir 35240, Turkey.
authors.forename: Emine Seker
authors.initials: ES
authors.lastname: Un
authors.affiliation: Department of Ophthalmology, Tepecik Traning and Research Hospital, Izmir 35240, Turkey.
authors.forename: Mehmet Giray
authors.initials: MG
authors.lastname: Ersoz
authors.affiliation: Department of Ophthalmology, Akdagmadeni State Hospital, Yozgat 66300, Turkey.
authors.forename: Yelda
authors.initials: Y
authors.lastname: Tasci
keywords: contact lens; intraocular pressure; rebound tonometer