Intraocular Pressure Study in Healthy Eyes: Goldmann Tonometry Versus Dynamic Contour Tonometry Versus No-Contact Tonometry Versus Scheimpflug Device
Narrative Responses:
Purpose
To determine the agreement in the measurement of intraocular pressure (IOP) between dynamic contour tonometer (DCT), Goldmann applanation tonometer (GAT), Ocular Response Analyzer (ORA) and Corvis (CST, Oculus,Wezlar, Germany) in healthy eyes with different corneal thickness (CCT).
Methods
76 eyes of 76 healthy subjects were examined, every subject underwent a complete ophthalmic evaluation, a Pentacam (Oculus, Wezlar, Germany) scan and three consecutive IOP measurements for each instruments (DCT, GAT, ORA and CST). IOP provided by every device were compared each other and the differences among them has been correlated with morphological parameters obtained by Pentacam. Statistical analysis has been run with SPSS (IBM Corp. Armonk, New York) software version 18.0.
Results
Mean age was 36.83 ± 10.63 years old. The mean IOP measurement obtained with GAT, CST, ORA and DCT was 15.62 ± 2.33, 17.24 ± 3.44, 15.99 ± 3.58 and 17.44 ± 2.51 mm Hg, respectively. The mean CCT was 543.63 ± 36.15 microns. A statistical significant difference between IOPcc and GAT (P < 0.0001), IOPcc and DCT (P < 0.001), GAT and DCT (P<0.0001), IOPg and GAT (P<0.002), and IOPg and DCT (P<0.0001), has been detected. In multivariable regression analysis, DCT IOP and GAT IOP measurements were significantly associated with CH and CRF (P<0.0001 for both)
Conclusion
According to our data, CTS provides IOP values statistically higher then GAT ones and not statistically different from DCT ones. Therefore CTS and GAT cannot be used interchangeably, if CTS should be used as next gold standard, higher IOP values will be considered as normal.