title: Non-Contact and Contact Tonometry in Corneal Edema.
abstract: OBJECTIVE
  To compare the intraocular pressure (IOP) values by Goldmann applanation tonometry (GAT) and Reichert 7 CR noncontact tonometry (R7CR-NCT) in patients with postsurgical corneal edema and to examine the impact of postoperative corneal edema on these values.
  
  
  METHODS
  Forty-six patients with grade 4 and 5 cataracts were included in this study. Intraocular pressure was measured using GAT and R7CR-NCT before and 1 day after phacoemulsification. Central corneal thickness (CCT) was determined before and after surgery to quantify postsurgical corneal edema. The R7CR-NCT provided a Goldmann-correlated IOP (IOPg) and corneal-compensated IOP (IOPcc).
  
  
  RESULTS
  The CCT increased significantly 1 day after surgery (the mean preoperative CCT, 543.5 ± 25.4 μm; the mean postoperative CCT, 681.5 ± 19.8 μm; p < 0.001), a mean increase of 26.7%. The preoperative R7CR-NCT measurements (the mean IOPcc, 18.8 ± 5.6 mm Hg; the mean IOPg, 17.8 ± 4.5 mm Hg) were significantly higher than GAT measurements (the mean GAT-IOP, 16.0 ± 3.4 mm Hg) (p < 0.001). On postoperative day 1, the R7CR-NCT measurement (the mean IOPcc, 27.0 ± 9.8 mm Hg; the mean IOPg, 25.1 ± 8.9 mm Hg) were significantly higher than GAT measurements (the mean GAT-IOP, 18.3 ± 7.9 mm Hg) (p < 0.001). The difference between postoperative R7CR-NCT and GAT-IOP values were significantly higher than the difference between preoperative R7CR-NCT and GAT-IOP values (p < 0.001 for both IOPcc to GAT-IOP and IOPg to GAT-IOP). The difference between postoperative IOPcc and GAT-IOP was significantly correlated to the change in CCT (r = 0.526, p < 0.001). Similarly, the difference between postoperative IOPg and GAT-IOP was significantly correlated to the change in CCT (r = 0.536, p < 0.001).
  
  
  CONCLUSIONS
  The R7CR-NCT IOP values were high in patients with postsurgical intensive corneal edema. Consequently, the difference between R7CR-NCT IOP and GAT-IOP increased in edematous corneas.
authors.affiliation: *MD †PhD Departments of Ophthalmology (SGG, AA, AK, LA, CS) and Biostatistics (ACY), Başkent University, Faculty of Medicine, Ankara, Turkey.
authors.forename: Sirel
authors.initials: S
authors.lastname: Gür Güngör
authors.forename: Ahmet
authors.initials: A
authors.lastname: Akman
authors.forename: Ali
authors.initials: A
authors.lastname: Küçüködük
authors.forename: Leyla
authors.initials: L
authors.lastname: Asena
authors.forename: Cem
authors.initials: C
authors.lastname: Şimşek
authors.forename: Ayşe Canan
authors.initials: AC
authors.lastname: Yazici
mesh_terms: D000368:Aged; D003315:Cornea / Q000473:pathology; D015715:Corneal Edema / Q000209:etiology / Q000503:physiopathology*; D063171:Corneal Pachymetry; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D019654:Lens Implantation, Intraocular; D008297:Male; D008875:Middle Aged; D018918:Phacoemulsification / Q000009:adverse effects; D019591:Pseudophakia / Q000503:physiopathology; D014065:Tonometry, Ocular / Q000295:instrumentation*