Comperieon of the Tono-Pen and the Goldmann Applanation Tonometry in Csreening Test

ABSTRACT

Tono-Pen was portable, miniaturized digital electronic tonometer. We compared Tono-Pen with Goldmann applanation tonometer through the mass screen studies on 634 eyes of 317 patients to evaluate the reliability of the Tono-Pen in determining intraocular pressure(IOP). We found 60% of the Tono-Pen readings to be within +/-1.5 mmHg of the Goldmann applanation tonometry readings and 85% to be within +/-2.5 mmHg difference. The correlation coefficient between the readings of the two instruments was 0.85. The Tono-Pen tonometry corresponded well to the Goldmann applanation tonometry in the 11 to 20 mmHg interval. We concluded that Tono-Pen tonometry is very useful in screening test to measure the intraocular pressure.