Concordance between Goldmann, Icare Pro®, Corvis ST® and Tonopen® tonometry, and their correlation with corneal thickness

Introduction: The objective is to evaluate the concordance of intraocular pressure (IOP) values by comparing three tonometers; Corvis ST (COR), Icare Pro (ICA) and Tonopen (TOP) with the gold standard, the Goldmann applanation tonometry (GAT and the effect of the measurements by the central corneal thickness (CCT). Methods: One hundred and eight eyes were selected (59 patients) who underwent IOP measurement with four instruments (Icare, Corvis, Tonopen and Goldmann). An univariate analysis was applied, and then a concordance analysis was performed in which the intraclass correlation coefficient (ICC) was calculated between the different instruments taking into account the corneal thicknesses to eliminate confounding effect in measurements. Results: 109 eyes (59 patients) were included, 66% women and 34% men. Average age 52.2 years (SD 13.87). Univariate analysis was performed and a mean age 52.2 (SD ± 13.87) and mean IOP were obtained for Goldman 15 (SD ± 2.94), Icare 15 (SD ± 2.47), Tonopen 14 ( SD ± 2.85), Corvis 14 (SD ± 2.67)