Correlation of intraocular pressure measured by applanation tonometry, noncontact tonometry and TonoPen with central corneal thickness
Abstract
The purpose of the study was to determine the dependence of intraocular pressure (IOP) measured by Goldmann applanation tonometer (AT), non-contact tonometer (BT) and Tono-Pen (TP) on central corneal thickness (CCT) as well as the respective comparison in relation to the central corneal thickness. Methods: CCT and IOP were assessed in 106 eyes of 106 subjects aged 7-77 years (mean 34.3 +- 17.1 years).
IOP was measured with BT, TP and AT. Central corneal thickness was assessed using ultrasound pachymetry.
The obtained data were statistically analyzed. Results: The mean CCT in 106 eyes was 572 +- 46 μm (range 455-701 μm).
A positive correlation between IOP and CCT was found in all types of tonometry. The change in measured IOP for a 100μm of CCT was 2.0, 2.5 and 5.6 mmHg for TP, AT and BT, respectively.
Conclusion: IOP measurement by all three methods is affected by CCT. The BT is influenced by CCT significantly more than are AT and TP.