Comparison of Dynamic Contour Tonometry and Goldmann Applanation Tonometry in Relation to Central Corneal Thickness

Abstract

Purpose: In this study we compared the intraocular pressures (IOPs) measured using dynamic contour tonometry (DCT) and Goldmann applanation tonometry (GAT) and investigated the correlation between central corneal thickness (CCT) and IOP. Methods: In a prospective study, 178 eyes of 91 subjects with glaucoma and glaucoma suspect were enrolled. IOP was measured using DCT and GAT and CCT was measured using ultrasound pachymetry. Each eye was classified into 1 of 3 groups according to their CCT: low CCT (Group A; CCT < 525 μm), normal CCT (Group B; 525 ≤ CCT < 561 μm), and high CCT (Group C; CCT ≥ 561 μm). In each group, we investigated the correlation between CCT and IOP measurement using GAT and DCT. Results: A significant correlation was found between CCT and IOP measured using GAT (p < 0.001), but not between CCT and IOP measured using DCT (p = 0.108) in all patients. Subgroup analysis showed that CCT affected IOP measured with GAT only in Group A (p = 0.027) and IOP measured with DCT was not affected by CCT in all 3 groups. Conclusions: IOP measured using GAT and DCT were significantly affected by CCT, especially when the CCT was low. CCT may have no effect on DCT thus, IOP measured using DCT is more reliable than GAT in patients with thin corneas. J Korean Ophthalmol Soc 2015;56(9):1392-1399

Challenges of the Intraocular Pressure Measurements in the Keratitis

“…Tear film instability can lead to fluctuations in IOP measurements due to changes in tear volume and composition. Several studies have reported that tear film instability can affect the accuracy of IOP measurements obtained using GAT, the most commonly used method for measuring IOP [4,5]. However, the effects of tear film can be avoided by dynamic contour tonometry, rebound tonometer, noncontact tonometry [6,7].…”