Comparison of Accuracy of Diaton Transpalpebral Tonometer Versus Goldmann Applanation Tonometer,Dynamic Contour Tonometer and Ocular Response Analyzer
PURPOSE: To compare intraocular pressure measurements obtained with the diaton transpalpebral tonometer with those from ocular response analyzer (ORA), dynamic (should be in same order as title)contour tonometry (DCT) and Goldmann applanation tonometry (GAT) in patients diagnosed with primary open-angle glaucoma (POAG) and glaucoma suspects, and to determine the effects of central corneal thickness (CCT) and corneal hysteresis (CH) on intraocular pressure (IOP) measurements with these devices.
METHODS: 40 patients (80 eyes) age 42-83 years with POAG and glaucoma suspects were included in the study. The average of ORA (corneal compensated IOP [IOP-ORAcc] and Goldmann-correlated IOP [IOP-ORAg]), DCT, GAT, and Diaton tonometer levels were compared and the devices were examined with respect to CCT and CH. Spearman's correlation tests were used for statistical analysis.
RESULTS: Mean CCT was 561,2±32,4mum and mean CH was 10.6+/-2.0 mmHg. Mean IOP obtained using DCT was 18,9±4,1 mmHg, whereas those provided by ORA were 18,2±3,4 mmHg for IOP-ORAcc and 18,4±3,5 mmHg for IOP-ORAg. The mean IOP obtained using GAT and Diaton were 18,4±4,1 mmHg and 17,0±3,0 mmHg respectively.The performed analysis of correlation between IOP meanings shows high conformity of results of Diaton with IOP-ORAcc and DCT. The differences between the measurements of DCT, ORA and Diaton were statistically significant. Correlated rates relations: between IOP-ORAcc and DCT 0,89; between IOP-ORAcc and Diaton 0,96; IOP-ORAcc and GAT 0,56; between GAT and Diaton 0,61; GAT and DCT 0,73; DCT and Diaton 0,87.
CONCLUSIONS: Transpalpebral Tonometry is an accurate method of IOP measurement that is also independent from the biomechanical characteristics of cornea.It can be recommended for IOP measurements of patients diagnosed with glaucoma including those cases where cornea pathology or cornea characteristics have been altered.