To compare the level of accuracy of intraocular pressure (IOP) measurements attained by non-contact tonometer (NCT), rebound tonometer (RT) Icare®, and Tono-Pen (TONO-PEN AVIA®), using Goldmann Applanation tonometer (GAT) as a reference value and to explore their clinical usefulness.

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.

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).

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.