Comparison of the Noncontact Tonometer with Goldmann Tonometer

ABSTRACT

Several kinds of non-contact tonometers have been used since the first non-contact tonometer was introduced in the 1970's in order to measure intraocular pressure with easiness and accuracy. However several problems were still remained because ofhe inaccuracy of the non-contact tonometer in high and low range of intraocular pressure. A new non-contact tonometer (Model CT-20, Japan) was recently introduced by Topcon Company to evaluate the clinical efficacy of the non-ccntact tonometers. The authors measured the intraocular pressure with Topcon tonometer, AO tonometer and Pulsair non-contat tonometer and compared the results with those measured with Goldmann tonometer. The results were as follows 1) The correlation coefficient between Goldmann and Topcon tonometer was 0.8452 (p=0.001), Goldmann and Pulsair tonometer was 0.7084 (p=O.OOl) and Goldmann and AO tonometer was 0.6048 (p=O.OOl) in the normal eyes. 2) The correlation coefficient between Goldmann and Topcon tonometer was 0.8651 (p=0.0001) in the ocular hypertensive or open angle glaucoma eyes. 3) The correlation coefficient between Goldmann and Topcon tonometer was 0.6987 (p=0.000l) in the low lOP eyes. 4) The correlation coefficient between Goldmann and Topcon tonometer was 0.6829 (p=0.0001) in the high myopic eyes. As above, a new-contact tonometer (Model CT-20, Japan) made by Topcon Company was relatively accurate in measuring not only the intraocular pressure of normal eyes but that of ocular hypertensive, low IOP and high myopic eyes.