Abstract
Purpose::
To investigate the relationship between intraocular pressure (IOP) measurements by dynamic contour tonometer (DCT) and by Goldmann applanation tonometer (GAT) and functional and structural glaucomatous damage.
Methods::
One hundred seventy-two glaucoma suspected eyes with open angle were evaluated at their initial examination. IOP was measured by DCT and by GAT for each eye. Visual field was evaluated on the Humphrey Field Analyzer (HFA). Retinal nerve fiber layer (RNFL) was evaluated with scanning laser polarimetry with variable corneal compensation (SLP-VCC) and optical coherence tomography (OCT). Linear regression analysis was performed between IOP measurements by DCT or GAT and functional and structural glaucomatous damage assessed by HVFA, SLP-VCC and OCT. We also compared the absolute values of residuals in each regression model to find out the difference between the association of IOP measured by each tonometer with glaucomatous damage.
Results::
Five out of 10 regression models showed statistical significance for both DCT and GAT (P<0.05). IOP measurements by DCT were significantly associated with mean deviation (MD), pattern standard deviation (PSD) among HVF indices, with inferior average among SLP-VCC parameters, and with inferior average, average thickness among OCT parameters (P<0.05). IOP measurements by GAT were significantly associated with MD, PSD, and CPSD among HVF indices, and with inferior average, average thickness among OCT parameters (P<0.05). There was no significant difference between the association of IOP measured by each tonometer and glaucomatous damage in any of the regression models.
Conclusions::
IOP measurements by DCT showed as similar degree of association with glaucomatous damage as those by GAT. DCT seems to be as effective as GAT in revealing the mechanism of pressure-dependent glaucomatous damage.
Keywords: intraocular pressure • nerve fiber layer