A comparison of intraocular pressure values obtained using a Goldmann applanation tonometer and a handheld version of applanation resonance tonometer: A preliminary report

Background. Despite the development of various methods of intraocular pressure (IOP) measurement, Goldmann applanation tonometry (GAT) is still the most popular. The measurement using GAT depends on the biomechanical properties of the cornea, such as the thickness, the radius of curvature, as well as the amount of the fluorescein used. Objectives. The aim of the study was to compare IOP values measured by GAT with those measured by applanation resonance tonometry (ART). Material and methods. A total of 47 patients (94 eyes), including 28 patients with primary open-angle glaucoma (POAG) and 19 subjects from the control group, were examined at the Glaucoma Outpatient Clinic of the Department and Clinic of Ophthalmology at Wroclaw Medical University (Poland). The measurements of IOP were performed using GAT and a handheld version of ART. Also, the central corneal thickness (CCT) of all patients was measured. Results. The study showed that the IOP values measured by both tonometers were comparable, but ART-acquired values were higher than GAT-obtained values both in the glaucomatous group and in the control group. CCT had little impact on mean IOP difference between GAT- and ART-obtained values. Conclusions. Applanation resonance tonometry is a precise method of IOP measurement and is less affected by biomechanical properties of the cornea than GAT. Our results show that ART is a new, promising, comfortable for both patients and doctors method of IOP measurement, which, in the future, can replace GAT.