Clinical Study
Eye (2009) 23, 262–269; doi:10.1038/sj.eye.6703102; published online 25 January 2008
Comparison of Goldmann applanation tonometry and dynamic contour tonometry in healthy and glaucomatous eyes
P Ceruti1, R Morbio1, M Marraffa1 and G Marchini1
1Department of Neurological and Visual Sciences, Eye Clinic, University of Verona, Verona, Italy
Correspondence: P Ceruti, Department of Neurological and Visual Sciences, Eye Clinic, Borgo Trento Hospital, University of Verona, Piazzale Stefani 1, Verona 37126, Italy. Tel: +39 3492 586 819; Fax: +39 0458 122 025; E-mail: pierre77@libero.it
Received 27 June 2007; Accepted 30 December 2007; Published online 25 January 2008.
Abstract
Purpose
To compare the measurements of intraocular pressure (IOP) with dynamic contour tonometry (DCT) and Goldmann applanation tonometry (GAT) in healthy and glaucomatous eyes and to evaluate the influence of corneal thickness (CCT), corneal curvature (CC), axial length (AL), and age on these tonometric alternatives.
Methods
Three hundred eyes of 100 healthy subjects, 100 patients with primary open angle glaucoma, and 100 patients with primary angle-closure glaucoma underwent IOP evaluation with DCT and GAT, and measurements of CCT, CC, and AL. Bland–Altman plots were used to evaluate the agreement between tonometers. Regression analysis was used to evaluate the influence of ocular structural factors on IOP measurements obtained with both tonometers.
Results
Bland–Altman plots indicated that the 95% limits of agreement between tonometers were -1.4 to 6.6 mmHg. DCT values measured 2.6
1.9 mmHg higher than GAT readings (P<0.001). The mean IOP difference between DCT and GAT (
IOP) was higher in healthy than in glaucomatous eyes and the magnitude of difference increased with increasing CCT. A significant reduction of IOP with an increase in both CCT (P<0.001) and IOP values (P<0.001) was found. Regression analysis showed no effect of CC, AL, and age on both DCT and GAT readings. In contrast to GAT (P<0.001), DCT measurements were not influenced by CCT (P=0.43).
Conclusions
IOP readings obtained by DCT were higher and less affected by CCT than those by GAT. The IOP was higher in healthy than in glaucomatous eyes and decreased in relation to increased CCT and IOP values.
Keywords:
tonometry, Goldmann applanation tonometry, dynamic contour tonometry, corneal thickness, glaucoma
MORE ARTICLES LIKE THIS
These links to content published by NPG are automatically generated
