Comparison of Intraocular Pressure Measured by Non-Contact Tonometer, Rebound Tonometer, Tono-Pen, and Goldmann Applanation Tonometer

ABSTRACT

PURPOSE: To compare the level of accuracy of intraocular pressure (IOP) measurements attained by non-contact tonometer (NCT), rebound tonometer (RT) Icare(R), and Tono-Pen (TONO-PEN AVIA(R)), using Goldmann Applanation tonometer (GAT) as a reference value and to explore their clinical usefulness. METHODS: In a prospective study of 71 normal eyes, IOP was measured with NCT, RT, Tono-Pen and GAT. The IOP values of were then compared between the eyes. RESULTS: RT showed statistically most significant agreement with the GAT [ICC 0.811, 95%CI 0.712-0.878]. In analysis of Bland-Altman plots, NCT showed the smallest mean bias (+0.2 mm Hg) and widest CI (95%CI; +/-5.05 mm Hg), RT showed relatively small mean bias (-0.7 mm Hg) and narrowest CI (95%CI; +/-3.75 mm Hg). CONCLUSIONS: There was a significant agreement between the RT and the GAT measurements. We expect RT to be considered as a reliable alternative when IOP measurement with GAT is not feasible.