Influence of Corneal Visualization Scheimpflug Technology Tonometry on Intraocular Pressure

Purpose To investigate the effect of Corneal Visualization Scheimpflug Technology tonometry (CST) on intraocular pressure (IOP).Design Cohort study.Participants Patients with and without primary open-angle glaucoma (POAG) were included.Methods Intraocular pressure was measured using the Icare rebound tonometer (ICRT; Icare Finland Oy) and the biomechanically corrected IOP (bIOP) using the CST. Intraocular pressure was measured at baseline with ICRT, followed by a CST measurement in one eye with the fellow eye acting as a control. Icare measurements were repeated at 10 seconds and 1, 2, 4, 8, 15, 30, and 60 minutes in both eyes. The ratio of test eye IOP to fellow eye IOP was used to control for intrasubject variation.Main outcome measures Intraocular pressure change following Corneal Visualization Scheimflug Technology tonometry.Results Forty participants (mean age, 54.09 ± 20.08 years) were included comprising 20 patients with POAG and 20 patients with no ocular abnormalities other than cataract. Mean central corneal thickness was similar in those without POAG (547.4 ± 55.05 μm) and with POAG (520.22 ± 37.59 μm; P = 0.14). No significant change was found in IOP measured with the ICRT in the fellow eye versus the 1-hour period in either the healthy (P = 0.87) or POAG (P = 0.92) group. Significant changes were found in IOP after CST measurement for both healthy (P P Conclusions Corneal Visualization Scheimpflug Technology tonometry causes a significant reduction in IOP in both glaucomatous and healthy eyes that lasts for at least 1 hour afterward.