title: Central corneal thickness and Diaton transpalpebral tonometry.
abstract: BACKGROUND
  To examine the effects of central corneal thickness on the measures obtained from transpalpebral tonometry (Diaton), and to identify correlations between intraocular pressure (IOP) measurements with Diaton and the Goldmann applanation tonometer (GAT).
  
  
  METHODS
  In this cross-sectional study, 162 eyes of 81 participants were included. Intraocular pressure measurements were obtained in all patients using Diaton and GAT. Central corneal thickness was determined by ultrasound pachymetry. The participants were stratified by corneal thickness: group I <530 microm (n = 56), group II 530-560 microm (n = 65), and group III >560 microm (n = 41).
  
  
  RESULTS
  There were moderate correlations between IOP readings obtained using the Diaton and corrected GAT (C-GAT) (r = 0.303; P < 0.0001), and between corrected Diaton (C-Diaton), and C-GAT (r = 0.399; P < 0.0001). The mean Diaton tonometer readings were lower than C-GAT measurements (Diaton-corrected GAT mean difference, 0.9 +/- 3.8 mmHg; c-Diaton-corrected GAT mean difference, 0.7 +/- 3.5 mmHg). Differences were detected between the groups of patients for the GAT values [2.4 +/- 3.6 mmHg for those with the thinnest corneas (<530 microm), 0.7 +/- 3.6 mmHg for those with moderate corneas (between 531 microm and 560 microm), and -0.6 +/- 3.6 mmHg for those with the thickest (>560 microm) corneas], whereas a significantly lower difference (0.9 +/- 3.8 mmHg) was noted for the Diaton values of all individuals.
  
  
  CONCLUSIONS
  The Diaton measurements show moderate correlation with those provided by applanation tonometry. The Diaton tonometer seems to be more affected by the corneal thickness, especially in the thinnest corneas.
authors.affiliation: Department of Ophthalmology, Cumhuriyet University School of Medicine, 58140 Sivas, Turkey. ilkertoker@gmail.com
authors.forename: Mustafa Ilker
authors.initials: MI
authors.lastname: Toker
authors.forename: Ayse
authors.initials: A
authors.lastname: Vural
authors.forename: Haydar
authors.initials: H
authors.lastname: Erdogan
authors.forename: Aysen
authors.initials: A
authors.lastname: Topalkara
authors.forename: Mustafa Kemal
authors.initials: MK
authors.lastname: Arici
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001837:Body Weights and Measures; D003315:Cornea / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D003430:Cross-Sectional Studies; D004547:Elastic Tissue; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D014065:Tonometry, Ocular; D014463:Ultrasonography